ECG Guru - Instructor Resources - High-grade AV Block https://www.ecgguru.com/ecg/high-grade-av-block en High-grade AV Block https://www.ecgguru.com/blog/high-grade-av-block-0 <div class="field field-name-field-blog-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/blog/high-grade-av-block-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/High%20grade%20AVB.jpg" width="3146" height="1729" alt="" /></a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even" property="content:encoded"><p>Why is this a high-grade AV block? If at least 3 P-waves are not conduced and there is normal AV conduction before and after, this can be considered a high-grade AV block. In this Holter strip, P1, P2 and all P-waves from P6 onwards are conducted, albeit with a prolonged PR interval (first-degree AV block). P3, P4, P5 are not conducted. A junctional escape beat is seen before P5. P5 can also not be conducted because the specific conduction system is still refractory at this time due to the junctional escape beat. </p> <p>Furthermore, a long QT time is observed!</p> </div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--2" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give High-grade AV Block 1/5</option><option value="40">Give High-grade AV Block 2/5</option><option value="60">Give High-grade AV Block 3/5</option><option value="80" selected="selected">Give High-grade AV Block 4/5</option><option value="100">Give High-grade AV Block 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.8</span></span> <span class="total-votes">(<span >6</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-mWcdg090beqpJbm95wvf9xWMv4ViK3Bg2DYqpBn2uRE" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_1"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fblog%2Fhigh-grade-av-block-0&amp;title=High-grade%20AV%20Block"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> <script type="text/javascript"> <!--//--><![CDATA[//><!-- if(window.da2a)da2a.script_load(); //--><!]]> </script></span></li> </ul> Mon, 11 Dec 2023 07:07:24 +0000 Dr A Röschl 886 at https://www.ecgguru.com https://www.ecgguru.com/blog/high-grade-av-block-0#comments Complete Heart Block or High Grade AVB? https://www.ecgguru.com/ecg/complete-heart-block-or-high-grade-avb <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/complete-heart-block-or-high-grade-avb"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/032007%20Complete%20AVB%20w%20Junctional%20escape%20edit.jpg" width="1800" height="1471" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal" style="text-align: left;" align="left"><strong><span style="color: #00b050;">The patient:</span></strong><span style="mso-spacerun: yes;">&nbsp; </span>This ECG was obtained from a 91-year-old woman who was complaining of weakness.<span style="mso-spacerun: yes;">&nbsp; </span>Unfortunately, we have no other information.<span style="font-size: 8pt;">&nbsp;</span></p><p class="MsoNormal" style="text-align: left;" align="left"><strong><span style="color: #00b050;">The ECG:<span style="mso-spacerun: yes;">&nbsp; </span></span></strong>This ECG has something for your basic students, and even more for the more advanced learners.<span style="mso-spacerun: yes;">&nbsp; </span>The first thing&nbsp; that anyone should notice is the slow rate.<span style="mso-spacerun: yes;">&nbsp; </span>The ventricular rate is around 35 bpm, and regular.<span style="mso-spacerun: yes;">&nbsp; </span>If the patient is showing signs of poor perfusion, we would stop here and prepare to increase the rate with a temporary pacemaker (transvenous or transcutaneous). Why is the rate so slow?&nbsp; There is no P wave in front of each QRS, so this is not sinus bradycardia.&nbsp; Rather, we see P waves at a rate of approximately 100 bpm, wit a very regular rhythm.&nbsp; Beginners should “march out” the P waves with calipers or by marking a straight edge piece of paper.&nbsp; There are 15 P waves on this ECG – some are buried within QRS complexes (QRS #3) or T waves (QRS #4).</p><p class="MsoNormal" style="text-align: left;" align="left">&nbsp;Because there are two distinct, regular rhythms, but they do not track with one another, we know this is possibly&nbsp;<strong>third-degree AV block</strong> (complete heart block).&nbsp; Another clue is that there are no steady, repetitive PR intervals, which means there is no relationship between the atrial rhythm and the ventricular rhythm.</p><p class="MsoNormal" style="text-align: left;" align="left">&nbsp;For more advanced learners, it is helpful to try to identify the origin of the escape rhythm.&nbsp; If it is junctional, the AV block is above the junction.&nbsp; If the escape is ventricular, the AV block is below the junction.&nbsp; A junctional rhythm is usually between 40 – 60 bpm, with a narrow QRS.&nbsp; Ventricular escape rhythms are usually less than 40 bpm and with wide QRS complexes.&nbsp;&nbsp;<span style="font-size: 8pt; line-height: 107%;">&nbsp;T</span>his ECG will be a little challenging on this front, because the rhythm has some characteristics of junctional rhythm and of ventricular rhythm.</p><p class="MsoNormal" style="text-align: left;" align="left">&nbsp;<span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span>·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><strong style="text-indent: -0.25in;">The QRS is wide</strong><span style="text-indent: -0.25in;">.</span><span style="mso-spacerun: yes;">&nbsp; </span><span style="text-indent: -0.25in;">Normally, that finding favors the diagnosis of ventricular rhythm, but interventricular conduction delays like bundle branch block can widen a junctional QRS. There is a small R’ in V1 and a wide little S wave in I and V6, favoring the diagnosis of right bundle branch block.</span><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><strong style="text-indent: -0.25in;">The frontal plane axis is abnormal</strong><span style="text-indent: -0.25in;">.</span><span style="mso-spacerun: yes;">&nbsp;&nbsp; </span><span style="text-indent: -0.25in;">This can be a sign of a ventricular rhythm, because the axis reflects the direction of the electrical flow in the ventricles.</span><span style="mso-spacerun: yes;">&nbsp; </span><span style="text-indent: -0.25in;">But, this left axis deviation is also seen in left anterior fascicular block, which is frequently paired with RBBB.</span><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><strong style="text-indent: -0.25in;">The slow rate</strong><span style="text-indent: -0.25in;"> is just about on the border between the intrinsic rates of the junctional and ventricular pacemakers.&nbsp;</span><span style="text-indent: -0.25in;">&nbsp;For those who care for patients in an emergency or primary care setting, it is important to emphasize that the origin of the block is not as important as supporting the patient’s need for rate as part of the important cardiac output equation.&nbsp;&nbsp;</span><span style="font-size: 8.0pt; line-height: 107%;">&nbsp;</span><span style="text-indent: -0.25in;">Another consideration for this patient is “what caused the AV block”?&nbsp; She is very old, and that certainly is a factor.&nbsp; But, on close inspection, we see ST changes.&nbsp; Specifically, there are flattened, slightly depressed ST segments in II, III, and aVF.&nbsp; AVR has the same flat shape, with some elevation. V1 has a very subtle ST changes, as well.&nbsp; This is a sign of diffuse ischemia (chronic or acute).&nbsp; The machine read the QTc as prolonged, but I measured using an online measuring tool, and got 464.8 with the Bazett equation.&nbsp;</span></p><p class="MsoNormal" style="text-align: left;" align="left">&nbsp;ECGs should always be approached in a systematic manner.&nbsp; When possible, patient presentation and symptoms should inform one’s decisions.</p><p class="MsoNormal" style="text-align: left;" align="left">EDIT:&nbsp; Please read the comment below from David Richley and Ken Grauer.&nbsp; They bring up a very good argument for "high-grade" AVB, which is a good conversation to have with more advanced students.&nbsp;&nbsp;</p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--2" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--4" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Complete Heart Block or High Grade AVB? 1/5</option><option value="40">Give Complete Heart Block or High Grade AVB? 2/5</option><option value="60">Give Complete Heart Block or High Grade AVB? 3/5</option><option value="80" selected="selected">Give Complete Heart Block or High Grade AVB? 4/5</option><option value="100">Give Complete Heart Block or High Grade AVB? 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.6</span></span> <span class="total-votes">(<span >5</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--2" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-F5Tnh-hj0qs6oppB1djuQA0v5vdNPu_S2uSzGwIKGTQ" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/subtle-st-changes" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Subtle ST changes</a></div><div class="field-item odd"><a href="/ecg/complete-heart-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Complete heart block</a></div><div class="field-item even"><a href="/ecg/third-degree-av-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Third-degree AV block</a></div><div class="field-item odd"><a href="/ecg/junctional-escape-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Junctional escape rhythm</a></div><div class="field-item even"><a href="/ecg/idioventricular-escape-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Idioventricular escape rhythm</a></div><div class="field-item odd"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item even"><a href="/ecg/diffuse-ischemia" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Diffuse ischemia</a></div><div class="field-item odd"><a href="/ecg/av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">AV Block</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_2"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fcomplete-heart-block-or-high-grade-avb&amp;title=Complete%20Heart%20Block%20or%20High%20Grade%20AVB%3F"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Wed, 11 Oct 2023 21:22:59 +0000 Dawn 873 at https://www.ecgguru.com https://www.ecgguru.com/ecg/complete-heart-block-or-high-grade-avb#comments Second-degree AV Block, Mobitz Type II https://www.ecgguru.com/blog/second-degree-av-block-mobitz-type-ii <div class="field field-name-field-blog-image field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/blog/second-degree-av-block-mobitz-type-ii"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/1_0.jpg" width="3063" height="1249" alt="" /></a></div><div class="field-item odd"><a href="/blog/second-degree-av-block-mobitz-type-ii"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/2_0.jpg" width="3061" height="1303" alt="" /></a></div></div></div><div class="field field-name-body field-type-text-with-summary field-label-hidden"><div class="field-items"><div class="field-item even" property="content:encoded"><p><span style="font-size: 10px;">We are observing EKG strip 1 in a Holter EKG recording; what can be said about it? There is a sinus rhythm with a normal PQ interval. After 3 sinus beats, a 2:1 AV block develops. When 2:1 AV block occurs, we should not refer to this as Wenckebach (Mobitz I) or Mobitz II, but rather as a high-grade AV block (other forms include: 3:1, 4:1, 5:1, etc.). The 2:1 block can be intranodally localized and behave benignly like a Wenckebach block typically does. However, it could also be infranodally localized with a potentially serious prognosis. Only EKG strip 2 allows us to make a precise diagnosis: here, the criteria for a Mobitz II block are met: sudden and unexpected failure of AV conduction with constant PP intervals (exception: ventriculophasic sinusarhrythmia), and PR intervals. Thus, a pacemaker indication is generally present here, unless there are remediable causes for the AV block. </span></p> <p><span style="font-size: 10px;">In general, it is important to note that the indication for a pacemaker must always be made in the context of all available facts and findings.</span></p> </div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--3" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--6" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Second-degree AV Block, Mobitz Type II 1/5</option><option value="40">Give Second-degree AV Block, Mobitz Type II 2/5</option><option value="60">Give Second-degree AV Block, Mobitz Type II 3/5</option><option value="80">Give Second-degree AV Block, Mobitz Type II 4/5</option><option value="100">Give Second-degree AV Block, Mobitz Type II 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="empty">No votes yet</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--3" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-3jtacF6aTPZvfcsbj1OdN1eY3TpUBng_Tu1NjcL19_4" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_3"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fblog%2Fsecond-degree-av-block-mobitz-type-ii&amp;title=Second-degree%20AV%20Block%2C%20Mobitz%20Type%20II"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Wed, 02 Aug 2023 08:35:01 +0000 Dr A Röschl 860 at https://www.ecgguru.com https://www.ecgguru.com/blog/second-degree-av-block-mobitz-type-ii#comments High-grade AV Block With Profound Bradycardia https://www.ecgguru.com/ecg/high-grade-av-block-profound-bradycardia <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/high-grade-av-block-profound-bradycardia"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AVB120%20High%20grade%20w%20sinus%20brady.jpg" width="1800" height="768" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">If you are an ECG instructor, you probably carefully choose ECGs to illustrate the topic you are teaching. One of the reasons for the existence of the ECG Guru website is our desire to provide lots of such illustrations for you to choose from.</p><p class="MsoNormal">Sometimes, though, an ECG does not clearly illustrate one specific dysrhythmia well, because the interpretation of the ECG depends on so many other factors.<span style="mso-spacerun: yes;">&nbsp; </span>In order to get it “right”, we would need to know information about the patient’s history, presentation, lab results, or previous ECGs. We might need to see the ECG done immediately before or after the one we are looking at.<span style="mso-spacerun: yes;">&nbsp; </span>Some ECG findings must ultimately be confirmed by an electrophysiology study before we can know for sure what is going on.</p><p class="MsoNormal">For those of us who are “ECG nerds”, it can be fun to debate our opinions and even more fun to hear from wiser, more advanced practitioners about their interpretations.</p><p class="MsoNormal">My belief, as a clinical instructor, is that we must teach strategies for treating the patient who has a “controversial” ECG that take into account the level of the practitioner, the care setting, and the patient’s hemodynamic status.<span style="mso-spacerun: yes;">&nbsp; </span>In some settings, it might be absolutely forbidden for a first-responder to cardiovert atrial fibrillation, for example.<span style="mso-spacerun: yes;">&nbsp; </span>But atrial fib is routinely cardioverted under controlled conditions in hospitals.<span style="mso-spacerun: yes;">&nbsp; </span>The general rule followed by emergency providers that “all wide-complex tachycardias are v tach until proven otherwise” has no doubt prevented deaths in situations where care providers did not agree on the origin of the tachycardia.</p><p class="MsoNormal"><strong><span style="color: #00b050;">The ECG: <span style="mso-spacerun: yes;">&nbsp;</span><span style="mso-spacerun: yes;">&nbsp;</span><span style="mso-spacerun: yes;">&nbsp;</span></span></strong>We do not have much patient information to go with this ECG, just that it is from a 71-year-old woman who developed severe hypotension and lost consciousness, but was revived with transcutaneous pacing.<span style="mso-spacerun: yes;">&nbsp;&nbsp; </span>Here is what we do know about this ECG:</p><p class="MsoListParagraphCxSpFirst" style="text-indent: -.25in; mso-list: l0 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span style="mso-list: Ignore;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><!--[endif]-->There are regular P waves, at a rate of about 39 bpm (sinus bradycardia).</p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -.25in; mso-list: l0 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span style="mso-list: Ignore;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><!--[endif]-->There are only two QRS complexes, shown in a total of six leads, and the rate is 13 bpm.</p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -.25in; mso-list: l0 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span style="mso-list: Ignore;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><!--[endif]-->The two PR intervals that are seen are the same at 368 ms, or .368 seconds (first-degree AVB).</p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -.25in; mso-list: l0 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span style="mso-list: Ignore;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><!--[endif]-->There are three P waves for every QRS complex. (second-degree AVB, Type II).</p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -.25in; mso-list: l0 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span style="mso-list: Ignore;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><!--[endif]-->The QRS complexes are 144 ms wide (.14 seconds).</p><p class="MsoListParagraphCxSpLast" style="text-indent: -.25in; mso-list: l0 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;"><span style="mso-list: Ignore;">·<span style="font: 7.0pt 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span></span><!--[endif]-->The QRS morphology cannot be evaluated in 12 leads here, but the pattern is consistent with right bundle branch block and left anterior fascicular block (bifascicular block).<span style="mso-spacerun: yes;">&nbsp; </span>Were we at the bedside, another 10 seconds of 12-lead ECG might produce a QRS that falls into the remaining leads’ sections of the tracing.</p><p class="MsoNormal">It would be very important to determine what caused the severe slowing of conduction. The paper speed has not been altered, and that should be ruled out whenever all rates and intervals are prolonged.<span style="mso-spacerun: yes;">&nbsp; </span>The severe sinus bradycardia, second-degree AVB, first-degree AVB, and bundle branch block all point to a global cause of poor conduction.<span style="mso-spacerun: yes;">&nbsp; </span>Electrolytes, drugs, vagal stimulation, possible acute M.I. – all of these need to be assessed.<span style="mso-spacerun: yes;">&nbsp; </span>And, eventually, the best definitive treatment will need to be decided.</p><p class="MsoNormal">But what is the <strong>MOST IMPORTANT </strong>issue here?<span style="mso-spacerun: yes;">&nbsp; </span><strong><span style="color: #c00000;">The RATE!</span></strong><span style="color: #c00000;"><span style="mso-spacerun: yes;">&nbsp; </span></span>And the patient’s response to the extremely slow rate.<span style="mso-spacerun: yes;">&nbsp; </span>Before we spend any time on the cause or treatment, we must address the rate and the patient’s hemodynamic status.<span style="mso-spacerun: yes;">&nbsp; </span>A transcutaneous pacemaker, if available, is called for.<span style="mso-spacerun: yes;">&nbsp; </span>CPR may be needed until the pacemaker can provide a perfusing rate. Rate-enhancing drugs may be used, and temporary transvenous pacing.<span style="mso-spacerun: yes;">&nbsp; </span>If the patient’s perfusion status is not addressed, the rest will not matter.</p><p class="MsoNormal">When students are taking an ECG class, they most often want to know, “what is the name of this rhythm?” and “what are some shortcuts or mnemonics I can use to remember the names of the rhythms?”.<span style="mso-spacerun: yes;">&nbsp; </span>They will be distressed if the instructor says, “This could be second-degree AVB, or we could call it high-grade AVB, or a longer strip might show it to be third-degree AVB.”<span style="mso-spacerun: yes;">&nbsp; </span>The instructor may even feel distressed by not knowing “for sure.”<span style="mso-spacerun: yes;">&nbsp; </span>But (and this is admittedly an editorial on my part), I think we do our students a disservice to lead them to believe that there is a “right” answer to every ECG strip. They need to know that some ECGs cannot and should not be read in a vacuum, but rather in light of the patient’s information. They need to know that comparison with a previous ECG, or adding additional leads, or running a longer strip may illuminate the problem.<span style="mso-spacerun: yes;">&nbsp; </span>But most of all, they should understand what immediate actions can safely be taken until we do “know for sure”.</p><p class="MsoNormal">We welcome your comments on this topic, whether you are a teacher, a student, a provider, or all of these.</p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--4" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--8" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give High-grade AV Block With Profound Bradycardia 1/5</option><option value="40">Give High-grade AV Block With Profound Bradycardia 2/5</option><option value="60">Give High-grade AV Block With Profound Bradycardia 3/5</option><option value="80" selected="selected">Give High-grade AV Block With Profound Bradycardia 4/5</option><option value="100">Give High-grade AV Block With Profound Bradycardia 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.5</span></span> <span class="total-votes">(<span >27</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--4" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-GYQ5aNeg1sHwbdLI6uMM9EJttzRt9jFp2Calt2MaAt0" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item odd"><a href="/ecg/sinus-bradycardia" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Sinus bradycardia</a></div><div class="field-item even"><a href="/ecg/second-degree-av-block-type-ii" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Second-degree AV block Type II</a></div><div class="field-item odd"><a href="/ecg/right-bundle-branch-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Right bundle branch block</a></div><div class="field-item even"><a href="/ecg/left-anterior-fascicular-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Left anterior fascicular block</a></div><div class="field-item odd"><a href="/ecg/left-anterior-hemiblock" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Left anterior hemiblock</a></div><div class="field-item even"><a href="/ecg/bifascicular-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Bifascicular block</a></div><div class="field-item odd"><a href="/ecg/first-degree-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">First-degree AV block</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_4"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fhigh-grade-av-block-profound-bradycardia&amp;title=High-grade%20AV%20Block%20With%20Profound%20Bradycardia"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Thu, 04 Jun 2020 20:24:18 +0000 Dawn 785 at https://www.ecgguru.com https://www.ecgguru.com/ecg/high-grade-av-block-profound-bradycardia#comments AV Block of Undetermined Type https://www.ecgguru.com/ecg/av-block-undetermined-type <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/av-block-undetermined-type"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/164%20High%20grade%20AVB.jpg" width="1800" height="265" alt="" /></a></div><div class="field-item odd"><a href="/ecg/av-block-undetermined-type"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/164%20High%20grade%20AVB%20Marked%20up.jpg" width="1800" height="265" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%;">This strip was obtained from a woman who presented to her doctor’s office with hypertension. While there is some artifact in the baseline, it is possible to determine the presence of P waves, thanks in part to having two leads to assess.&nbsp; We have provided an unmarked version of the strip for you to use, and also a marked version for the sake of this discussion.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; color: #00b050;">The underlying rhythm</span><span style="font-size: 12pt; line-height: 107%;"> is sinus bradycardia, at about 60 bpm, but with some slight variation in the P to P intervals (about 920 ms to 1040 ms). Because of the artifact, it is difficult to determine the exact P to P intervals, and the exact morphology of the P waves. So, we can’t say for sure that the P waves are all alike.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; color: #00b050;">The AV block </span><span style="font-size: 12.0pt; line-height: 107%;">occurs at a 3:1 ratio.&nbsp; That is, for every three P waves, one is conducted and produces a QRS complex.&nbsp; When the P waves are not conducted, an escape rhythm occurs.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; color: #00b050;">The escape rhythm </span><span style="font-size: 12.0pt; line-height: 107%;">occurs at an escape interval of about 1720 ms.&nbsp; In other words, when a QRS does not occur by that time, the escape beat is produced.&nbsp; It appears to be from the AV junction, in spite of the slow rate, because the escape QRSs look like the sinus conducted QRSs.&nbsp; Both sinus and junctional rhythms are conducted along the bundle branches and produce the same QRS morphology.&nbsp; The QRS complexes are approximately .08-.10 seconds wide.&nbsp; Note that QRS complexes numbered 3, 5, and 7 have a P wave fused to the beginning of the QRS, making the QRS look wide when it is not.&nbsp;&nbsp; A junctional escape rhythm results from AV block in the AV node, as the junction is the first available pacemaker below the AVN.</span><span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%;">This patient was scheduled for a treadmill stress test in her doctor’s office, which was cancelled. She had no cardiac symptoms at the time of the ECG, except the above-noted hypertension.&nbsp; Unexplained bradycardia, especially when accompanied by AV node blocks, should trigger an assessment for inferior wall M.I., since the inferior wall of the LV shares a blood supply with the SA and AV nodes in the majority of people.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%;">Whether an AV block is "second-degree" or "third-degree" may not matter as much as WHERE the block is and what the resulting rate is.&nbsp; If the block is in the AV node, as opposed to the bundle branches or lower His bundle, the patient will have the benefit of a junctional escape rather than a ventricular escape rhythm. AV node level blocks tend to be temporary and reversible, while sub-Hisian blocks can be more permanent and more life-threatening. The rate, and the cardiac output, matter more to the patient than the "degree".&nbsp; Should the rate be so slow that the patient loses perfusion, a pacemaker may be required to increase it.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%;"> Our thanks to Palm Beach Gardens Fire Rescue for donating this strip.</span></p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--5" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--10" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give AV Block of Undetermined Type 1/5</option><option value="40">Give AV Block of Undetermined Type 2/5</option><option value="60" selected="selected">Give AV Block of Undetermined Type 3/5</option><option value="80">Give AV Block of Undetermined Type 4/5</option><option value="100">Give AV Block of Undetermined Type 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3</span></span> <span class="total-votes">(<span >7</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--5" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-vA-wFEnoc7OCugMZ0iyF2-gsVjhHYyXZ29HeGK099UM" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item odd"><a href="/ecg/second-degree-av-block-type-ii" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Second-degree AV block Type II</a></div><div class="field-item even"><a href="/ecg/escape-capture-bigeminy" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Escape-capture bigeminy</a></div><div class="field-item odd"><a href="/ecg/rhythm-strip" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Rhythm strip</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_5"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fav-block-undetermined-type&amp;title=AV%20Block%20of%20Undetermined%20Type"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Wed, 22 Nov 2017 22:48:37 +0000 Dawn 741 at https://www.ecgguru.com https://www.ecgguru.com/ecg/av-block-undetermined-type#comments Inferior Wall M.I. With Right Ventricular M.I. https://www.ecgguru.com/ecg/inferior-wall-mi-right-ventricular-mi-1 <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/inferior-wall-mi-right-ventricular-mi-1"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/IWR104A_0.jpg" width="1800" height="708" alt="" /></a></div><div class="field-item odd"><a href="/ecg/inferior-wall-mi-right-ventricular-mi-1"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/IWR104B_0.jpg" width="1800" height="687" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal">This ECG was recorded from a 75-year-old man with substernal chest pain and diaphoresis. &nbsp;It shows a pretty classic picture of acute inferior wall M.I. The second ECG is a repeat tracing with the V4 wire moved to the V4 Right position, and it is positive for right ventricular M.I.&nbsp; The patient was found to have a 100% occlusion of the right coronary artery, which was opened and stented in the cath lab.</p><p class="MsoNormal">There are several other examples of IWMI with RVMI in our archives, so we will confine this commentary to the ECG signs that make these tracings so typical of right coronary artery occlusion. Once you are familiar with the typical pattern of IWMI / RVMI, it is easy to see, even when the ST elevation is subtle (as this one certainly is NOT).</p><p class="MsoNormal"><strong>Signs of IWMI in these ECGs are</strong>:&nbsp;</p><p class="MsoListParagraphCxSpFirst" style="text-indent: -.25in; mso-list: l1 level1 lfo1;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->ST elevation in inferior leads II, III and aVF.</p><p class="MsoListParagraphCxSpFirst" style="text-indent: -.25in; mso-list: l1 level1 lfo1;"><span style="text-indent: -0.25in; font-size: 13.008px; font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><span style="text-indent: -0.25in; font-size: 13.008px;">Reciprocal ST depression in leads I and aVL.</span><span style="text-indent: -0.25in; font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal"><strong>Signs of RVMI in these ECGs are:</strong></p><p class="MsoListParagraphCxSpFirst" style="text-indent: -.25in; mso-list: l0 level1 lfo2;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->ST elevation in V4 right.</p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -.25in; mso-list: l0 level1 lfo2;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->ST elevation in V1 without ST elevation in V2.</p><p class="MsoListParagraphCxSpLast" style="text-indent: -.25in; mso-list: l0 level1 lfo2;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->ST elevation in lead III is greater than ST elevation in lead II.</p><p class="MsoNormal"><strong>Other common findings in right coronary occlusion that are seen in these ECGs:</strong></p><p class="MsoListParagraphCxSpFirst" style="text-indent: -.25in; mso-list: l2 level1 lfo3;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->ST depression in V2.&nbsp; If not for the RVMI causing elevation in V1, there would be ST depression in V1 also.&nbsp; This is a reciprocal ST depression, reflecting STE in the posterior wall.&nbsp; The posterior wall is called the lateral wall by some because it is oriented behind the anterior wall, but toward the patient’s left side.&nbsp; This area across from V1, V2, and sometimes V3 can have ST elevation if an inferior wall M.I. is large enough to extend up toward the base of the heart.&nbsp; Electrodes placed on the left side of the back might show the STE.</p><p class="MsoListParagraphCxSpMiddle" style="text-indent: -.25in; mso-list: l2 level1 lfo3;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->Bradycardia and heart block.&nbsp; Sinus and AV node blocks often occur in IWMI because the two nodes usually have the same blood supply as the inferior wall and right ventricle.&nbsp; AV blocks are usually of the “Type I” variety.&nbsp; There may be varying amounts of first-degree AVB, second-degree AVB, Type I (Wenckebach), and even third-degree, or complete heart block.&nbsp; In the first ECG, at 3:17, &nbsp;we see some 2:1 AVB. There are also some periods where there is AV dissociation with junctional escape, or possibly very long PR intervals (beats 1,5,6). &nbsp;In the second ECG, at 3:27, we see a slight increase in the sinus rate with Wenckebach periods (beats 5-8).&nbsp;</p><p class="MsoListParagraphCxSpLast" style="text-indent: -.25in; mso-list: l2 level1 lfo3;"><!--[if !supportLists]--><span style="font-family: Symbol; mso-fareast-font-family: Symbol; mso-bidi-font-family: Symbol;">·<span style="font-variant-numeric: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: 'Times New Roman';">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </span></span><!--[endif]-->Bradycardia, even if caused by AV block, might actually be helpful to the M.I. patient, as a rapid rate could use up the heart’s resources and hasten heart failure.&nbsp; The rate should be evaluated in light of the patient’s hemodynamic condition:&nbsp; blood pressure, skin color and temperature, and mental status.<span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal">Being able to quickly and confidently recognize the patterns produced by RCA occlusion will help when you are confronted with a symptomatic patient whose ECG has minimal ST elevation.</p><p class="MsoNormal">&nbsp;</p><p class="MsoNormal">Our thanks to Palm Beach Gardens, FL Fire Rescue for donating these ECGs.&nbsp;</p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--6" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--12" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Inferior Wall M.I. With Right Ventricular M.I. 1/5</option><option value="40">Give Inferior Wall M.I. With Right Ventricular M.I. 2/5</option><option value="60">Give Inferior Wall M.I. With Right Ventricular M.I. 3/5</option><option value="80" selected="selected">Give Inferior Wall M.I. With Right Ventricular M.I. 4/5</option><option value="100">Give Inferior Wall M.I. With Right Ventricular M.I. 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4</span></span> <span class="total-votes">(<span >2</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--6" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-dBvWtEx_STq1ZWjwTOOTJI233L1JEDxE9Ie9JVXUiB4" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/inferior-mi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Inferior M.I.</a></div><div class="field-item odd"><a href="/ecg/right-ventricular-mi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Right ventricular M.I.</a></div><div class="field-item even"><a href="/ecg/stemi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">STEMI</a></div><div class="field-item odd"><a href="/ecg/st-elevation" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">ST elevation</a></div><div class="field-item even"><a href="/ecg/reciprocal-st-changes" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Reciprocal ST changes</a></div><div class="field-item odd"><a href="/ecg/second-degree-av-block-type-i" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Second-degree AV block Type I</a></div><div class="field-item even"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item odd"><a href="/ecg/21-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">2:1 AV block</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_6"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Finferior-wall-mi-right-ventricular-mi-1&amp;title=Inferior%20Wall%20M.I.%20With%20Right%20Ventricular%20M.I."><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Sun, 29 Oct 2017 00:36:38 +0000 Dawn 740 at https://www.ecgguru.com https://www.ecgguru.com/ecg/inferior-wall-mi-right-ventricular-mi-1#comments Second-degree AV Block, Type II? https://www.ecgguru.com/ecg/second-degree-av-block-type-ii-0 <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/second-degree-av-block-type-ii-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/2nd%20deg%20Type%20II%203%20to%201.jpg" width="1887" height="1454" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">This ECG is taken from an elderly woman who complains of feeling weak and tired. We have no other clinical information, unfortunately.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">There is an obvious bradycardia, with more P waves than QRS complexes.&nbsp; Here is what we see:</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*&nbsp; Atrial rate is around 115/min. and P waves are regular and all alike.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*&nbsp; Ventricular rate is around 35/min. and QRS complexes are regular and all alike.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*&nbsp; PR intervals, when they occur, are all the same at 162 ms.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*&nbsp; QRS duration is wide at 122 ms.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">*&nbsp; QTc interval is prolonged at 549 ms. </span></p><p class="MsoNormal"><strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">What does this mean? &nbsp;</span></strong><span style="font-family: Arial, sans-serif; font-size: 12pt;">There is sinus tachycardia with second-degree AV block because the atrial rate is over 100/min, but not all P waves are conducted.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">&nbsp; </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">The AV block looks like a Type II (Mobitz II) block because the PR intervals are all the same.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">&nbsp; </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">This is a reliable indicator of conduction. (Not third-degree AVB). &nbsp;</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">The wide QRS complexes are due to right bundle branch block.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">&nbsp; </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">The ECG signs of RBBB are: 1) wide QRS; 2) supraventricular rhythm; and 3) rSR’ pattern in V1 and Rs, with a wide little s wave, in Leads I and V6.</span></p><p class="MsoNormal"><strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">Type II AV blocks</span></strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;"> are almost always blocks of the intraventricular conduction system.&nbsp; That is, they occur in the region of the bundle branches.&nbsp; A second-degree, Type II AVB is an “intermittent tri-fascicular block”.&nbsp; That is, one or two of the three main fascicles of the bundle branches is constantly blocked, and the remaining fascicle(s) is intermittently blocked.&nbsp; When all three fascicles are blocked, there is no QRS following the P wave. When the intermittently-blocked fascicle conducts, we see a QRS.&nbsp; Often, that QRS will be conducted with a bundle branch block pattern.</span></p><p class="MsoNormal"><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">In this case, there is a constant right bundle branch block.&nbsp; The left bundle branch appears to be intermittently blocked, resulting in no conduction for two beats.&nbsp; So, we would call this a 3:1 AV block. </span></p><p class="MsoNormal"><strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">What about the QTc interval?&nbsp;</span></strong><span style="font-family: Arial, sans-serif; font-size: 12pt;">The QT interval (corrected to a rate of 60) is 549 ms.</span><span style="font-family: Arial, sans-serif; font-size: 12pt;">&nbsp; </span><span style="font-family: Arial, sans-serif; font-size: 12pt;">This is prolonged in any age or gender. QTc intervals over 500 ms are associated with an increased risk of </span><a style="font-family: Arial, sans-serif; font-size: 12pt;" href="https://www.ecgguru.com/ecg/atrial-fib-cardiac-arrest/">Torsades de Pointes.</a><span style="font-size: 13.008px;">&nbsp;</span></p><p class="MsoNormal"><strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">Additional teaching points. </span></strong><span style="font-size: 12.0pt; line-height: 107%; font-family: 'Arial',sans-serif;">This is a great ECG to show students how P waves can “hide” in T waves.&nbsp; By carefully marching out the P waves, we can find the hidden ones, and also see how they affect the shapes of the T waves in each lead.&nbsp; V3 shows the P wave occurring on the upslope of the T wave. It is also a good case for discussion of treatment of bradycardias.&nbsp; At this rate, it is very likely that the patient is hemodynamically compromised.&nbsp; Generally, emergency transthoracic pacing is used until a temporary transvenous or permanent transvenous pacemaker can be applied. Patients with Type II blocks do not often respond well to atropine because the problem lies in the intraventricular conduction system. Atropine exerts it’s rate-increasing effect in the SA and AV nodes and by blocking the vagus nerve. Type II AV blocks are generally considered serious and prone to worsening.&nbsp; A complete heart block occurring at this anatomic level would have a ventricular escape rhythm rather than a junctional escape rhythm.&nbsp; AV blocks occurring at the level of the AV node, such as second-degree, Type I &nbsp;(Wenckebach) blocks, would be likely to have junctional escape. Prolonged QT intervals can be very serious, and the patient should be evaluated for reversible causes of the prolonged QT interval, while <a href="http://emedicine.medscape.com/article/157826-treatment#d15">medications known to prolong the QT interval</a> should be avoided.</span></p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--7" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--14" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Second-degree AV Block, Type II? 1/5</option><option value="40">Give Second-degree AV Block, Type II? 2/5</option><option value="60">Give Second-degree AV Block, Type II? 3/5</option><option value="80" selected="selected">Give Second-degree AV Block, Type II? 4/5</option><option value="100">Give Second-degree AV Block, Type II? 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4</span></span> <span class="total-votes">(<span >4</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--7" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-p5EYAjV9JQbTkVN6pd6EfcYH1WZsKOXWCojIFUwTIno" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/21-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">2:1 AV block</a></div><div class="field-item odd"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item even"><a href="/ecg/second-degree-av-block-type-ii" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Second-degree AV block Type II</a></div><div class="field-item odd"><a href="/ecg/prolonged-qt-interval" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Prolonged QT interval</a></div><div class="field-item even"><a href="/ecg/av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">AV Block</a></div><div class="field-item odd"><a href="/ecg/right-bundle-branch-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Right bundle branch block</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_7"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fsecond-degree-av-block-type-ii-0&amp;title=Second-degree%20AV%20Block%2C%20Type%20II%3F"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Thu, 02 Feb 2017 05:09:56 +0000 Dawn 724 at https://www.ecgguru.com https://www.ecgguru.com/ecg/second-degree-av-block-type-ii-0#comments High-Grade AV Block, Second-degree AVB Type II https://www.ecgguru.com/ecg/high-grade-av-block-second-degree-avb-type-ii <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/high-grade-av-block-second-degree-avb-type-ii"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AVB102%202nd%20deg%20AVB%20II%20wrng%20dx.jpg" width="1800" height="687" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p style="margin: 12pt 0in; line-height: 15pt;"><span style="font-size: 10pt; font-family: 'Lucida Sans Unicode', sans-serif;">This ECG shows a <strong>second-degree AV block, Mobitz Type II.</strong>&nbsp; It is also called <a title="LITFL High Grade AV Block" href="http://lifeinthefastlane.com/ecg-library/basics/high-grade-block/"><strong>“high grade AV</strong> <strong>block”</strong></a> because there is a 3:1 ratio of P waves to QRS complexes and a resulting slow rate.</span></p><p style="margin: 12pt 0in; line-height: 15pt;"><span style="font-family: 'Lucida Sans Unicode', sans-serif; font-size: 10pt; line-height: 15pt;">Right bundle branch block and left anterior fascicular block are also present, as is common with Type II blocks.&nbsp; The underlying rhythm is sinus.&nbsp; Second-degree AVB, Type II, usually represents an intermittent tri-fascicular block:&nbsp;&nbsp;often right bundle branch block and left anterior fascicular block (hemiblock) are present, and the left posterior fascicle develops an </span><strong style="font-family: 'Lucida Sans Unicode', sans-serif; font-size: 10pt; line-height: 15pt;">intermittent block</strong><span style="font-family: 'Lucida Sans Unicode', sans-serif; font-size: 10pt; line-height: 15pt;">.&nbsp; During times of tri-fascicular block, the P waves are not conducted.&nbsp; When the posterior fascicle </span><strong style="font-family: 'Lucida Sans Unicode', sans-serif; font-size: 10pt; line-height: 15pt;">is</strong><span style="font-family: 'Lucida Sans Unicode', sans-serif; font-size: 10pt; line-height: 15pt;"> conducting, a QRS occurs.</span></p><p style="margin: 12pt 0in; line-height: 15pt;"><span style="font-size: 10pt; font-family: 'Lucida Sans Unicode', sans-serif;">A differential diagnosis for this ECG is complete heart block with ventricular escape rhythm. &nbsp;A longer strip would be needed to see the P waves eventually dissociate from the QRSs, if they are going to do so. &nbsp;Clinically, there is really little difference in the treatment of a high-grade "second degree" block and a "third degree" block. Both are treated with emergency support of the slow rate, as needed, and then a permanent implanted pacemaker.</span></p><p><span style="font-size: 10pt; line-height: 107%; font-family: 'Lucida Sans Unicode', sans-serif;">It is notable that, in this case, the interpretation given by the machine is completely incorrect, even including the intervals.&nbsp; This is not common, but does occur.&nbsp; The machine's interpretation should be considered, but not followed blindly.<br /> <!--[if !supportLineBreakNewLine]--><br /> <!--[endif]--></span></p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--8" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--16" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give High-Grade AV Block, Second-degree AVB Type II 1/5</option><option value="40">Give High-Grade AV Block, Second-degree AVB Type II 2/5</option><option value="60">Give High-Grade AV Block, Second-degree AVB Type II 3/5</option><option value="80">Give High-Grade AV Block, Second-degree AVB Type II 4/5</option><option value="100" selected="selected">Give High-Grade AV Block, Second-degree AVB Type II 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4.8</span></span> <span class="total-votes">(<span >6</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--8" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-8IWd7uG-vN4CGMkwqKoR1qypfzQA1WIMJRuCbynNh0Y" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/second-degree-av-block-type-ii" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Second-degree AV block Type II</a></div><div class="field-item odd"><a href="/ecg/av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">AV Block</a></div><div class="field-item even"><a href="/ecg/ecg-misdiagnosis-machine" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">ECG misdiagnosis by machine</a></div><div class="field-item odd"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_8"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fhigh-grade-av-block-second-degree-avb-type-ii&amp;title=High-Grade%20AV%20Block%2C%20Second-degree%20AVB%20Type%20II"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Thu, 04 Jun 2015 03:25:16 +0000 Dawn 642 at https://www.ecgguru.com https://www.ecgguru.com/ecg/high-grade-av-block-second-degree-avb-type-ii#comments Complete AV Block https://www.ecgguru.com/ecg/complete-av-block-0 <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/complete-av-block-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AVB110%20B_0.jpg" width="1800" height="644" alt="" /></a></div><div class="field-item odd"><a href="/ecg/complete-av-block-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AVB110%20B%20w%20markup.jpg" width="1800" height="644" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>This ECG is from an 84-year-old man who experienced dizziness and a fall. &nbsp;He was not injured in the fall. &nbsp;In this ECG, we can clearly see regular P waves at about 110 per minute. &nbsp;We also see wide QRS complexes at about 52 per minute. &nbsp;There is AV &nbsp;dissociation - there are no regular PR intervals, or even progressively-prolonging PR intervals. &nbsp;The atrial and the ventricles are beating to separate rhythms. &nbsp;What is interesting about this rhythm is the origin of the escape rhythm. &nbsp;The wide complex suggests a ventricular focus and the rate suggests supraventricular origin. &nbsp;Near the end of the ECG, the escape rhythm either fails or slows significantly. &nbsp;To see the next 12-lead ECG for this patient, go to this<a title="110 C CHB" href="http://ecgguru.com/ecg/third-degree-av-block"> LINK.</a></p><p>The second ECG makes it more clear that this is an idioventricular escape rhythm, but the morphology of the QRS complexes suggested that, even in the first ECG when the rate was faster. &nbsp;There are several clues that this is probably ventricular, including a very "backward" axis with aVR being upright and II, III, and aVF all being negative. &nbsp;Also, V6 is negative, and there is nearly precordial concordance: &nbsp;all except V1 are negative. &nbsp;The morphology of the QRS does not fit a diagnosis of either left bundle branch block OR right bundle branch block. &nbsp;The evidence points to a ventricular origin for this escape rhythm, and the patient quickly goes on to slow down severely. &nbsp;Ventricular escape rhythm strongly suggests a sub-Hisian location for the block, and they tend to be more life-threatening than supra-Hisian blocks.</p><p>The take-home clinical lesson here is to BE PREPARED for worsening of the rate whenever AV block is present, especially high-grade AV block or sub-Hisian block. &nbsp;This ECG is a very good one for teaching students to "march out" P waves, and find "hidden" P waves. &nbsp;We have included a marked copy of this ECG to indicate those P waves.</p><p>Thanks to Sebastian Garay for donating these ECGs.</p><p>&nbsp;</p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--9" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--18" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give Complete AV Block 1/5</option><option value="40">Give Complete AV Block 2/5</option><option value="60">Give Complete AV Block 3/5</option><option value="80" selected="selected">Give Complete AV Block 4/5</option><option value="100">Give Complete AV Block 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.5</span></span> <span class="total-votes">(<span >4</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--9" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-q3LK3V5BeEir-DdYLrHKF9Lc58P2p2uwLSAPrUif_Xs" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/complete-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Complete AV block</a></div><div class="field-item odd"><a href="/ecg/idioventricular-escape-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Idioventricular escape rhythm</a></div><div class="field-item even"><a href="/ecg/av-dissociation" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">AV dissociation</a></div><div class="field-item odd"><a href="/ecg/third-degree-av-block-1" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Third-degree AV block</a></div><div class="field-item even"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item odd"><a href="/ecg/ventricular-standstill" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Ventricular standstill</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_9"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fcomplete-av-block-0&amp;title=Complete%20AV%20Block"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Tue, 16 Sep 2014 20:26:50 +0000 Dawn 599 at https://www.ecgguru.com https://www.ecgguru.com/ecg/complete-av-block-0#comments High-grade AV Block https://www.ecgguru.com/ecg/high-grade-av-block-0 <div class="field field-name-field-ecg field-type-image field-label-hidden"><div class="field-items"><div class="field-item even"><a href="/ecg/high-grade-av-block-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AVB113.jpg" width="1800" height="656" alt="" /></a></div><div class="field-item odd"><a href="/ecg/high-grade-av-block-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AVB113%2010%2037.jpg" width="1800" height="695" alt="" /></a></div></div></div><div class="field field-name-field-ecg-interpretation field-type-text-long field-label-hidden"><div class="field-items"><div class="field-item even"><p>To continue on a topic started by Jason Roediger in his <a href="http://ecgguru.com/blog/jasons-blog-ecg-challenge-month-february-2014">February ECG Challenge</a> -</p><p>This series of two ECGs was taken from a 71-year-old man who complained of dizziness and near-syncope the day before these ECGs were done. &nbsp;He was seen in an Emergency Dept., and advised to follow up with a neurologist. On the day of these ECGs, still feeling dizzy and like he would pass out, he called EMS again. &nbsp;He denied chest pain. &nbsp;We do not know his past medical history. &nbsp;The first ECG was taken at 10:22 am. &nbsp;His BP was 177/76 and SpO2 99%. &nbsp;It shows a regular sinus rhythm (p waves marked by small asterisks) at a rate of about 75 / min. &nbsp;There is a high-grade AV block, meaning that some P waves are conducted (beats 2, 4, 7), but most are not. &nbsp;In addition, he has an escape rhythm, probably ventricular, at a rate of just over 40 / min. &nbsp;The overall effect of the escape rhythm is to keep the heart rate above 40 beats per minute.</p><p>Fifteen minutes later, at 10:37 am, another ECG is taken. &nbsp;The patient's BP is 154/86. &nbsp; This ECG shows the high-grade AV block quite well, but this time, most of the QRS complexes on the strip are conducted from P waves. &nbsp;It is difficult to see all the P waves in every lead, but if you remember that all three channels are run simultaneously, you will find evidence of the P waves in at least one of the three leads represented at any given time. &nbsp;(Example: &nbsp;V1, V2, and V3 - V3 shows the P waves well). &nbsp;The next-to-last QRS on the page is interesting, as it has a different PRI than the normally conducting beats. &nbsp;Is this a fusion beat or an aberrantly-conducted one? &nbsp; It probably does not matter to the outcome of the patient.&nbsp;</p><p>The <strong>slowing of the rate</strong> in the second strip gives us a clue as to why the patient felt dizzy, but the blood pressures recorded did not catch hypotension. &nbsp;Possibly if the patient had been standing instead of lying on a stretcher, we would have seen more hemodynamic changes.</p><p>Unfortunately, we do not know the outcome of this patient, but it seems he is a candidate for an implanted pacemaker.</p></div></div></div><div class="field field-name-field-rate-this-content field-type-fivestar field-label-above"><div class="field-label">Rate this content:&nbsp;</div><div class="field-items"><div class="field-item even"><form class="fivestar-widget" action="/taxonomy/term/109/feed" method="post" id="fivestar-custom-widget--10" accept-charset="UTF-8"><div><div class="clearfix fivestar-average-text fivestar-average-stars fivestar-form-item fivestar-hearts"><div class="form-item form-type-fivestar form-item-vote"> <div class="form-item form-type-select form-item-vote"> <select id="edit-vote--20" name="vote" class="form-select"><option value="-">Select rating</option><option value="20">Give High-grade AV Block 1/5</option><option value="40">Give High-grade AV Block 2/5</option><option value="60">Give High-grade AV Block 3/5</option><option value="80">Give High-grade AV Block 4/5</option><option value="100" selected="selected">Give High-grade AV Block 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4.3</span></span> <span class="total-votes">(<span >4</span> votes)</span></div></div> </div> </div> </div><input class="fivestar-submit form-submit" type="submit" id="edit-fivestar-submit--10" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-jHnwbmQ-P1BYTHOIaPW-_4gBT8xP3DmigsJjAYfY11A" /> <input type="hidden" name="form_id" value="fivestar_custom_widget" /> </div></form></div></div></div><div class="field field-name-field-taxonomy field-type-taxonomy-term-reference field-label-above"><div class="field-label">Related Terms:&nbsp;</div><div class="field-items"><div class="field-item even"><a href="/ecg/av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">AV Block</a></div><div class="field-item odd"><a href="/ecg/high-grade-av-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">High-grade AV Block</a></div><div class="field-item even"><a href="/ecg/escape-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Escape rhythm</a></div><div class="field-item odd"><a href="/ecg/second-degree-av-block-type-ii" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Second-degree AV block Type II</a></div><div class="field-item even"><a href="/ecg/idioventricular-escape-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Idioventricular escape rhythm</a></div></div></div><ul class="links inline"><li class="addtoany first last"><span><span class="a2a_kit a2a_target addtoany_list" id="da2a_10"> <a class="a2a_dd addtoany_share_save" href="https://www.addtoany.com/share#url=https%3A%2F%2Fwww.ecgguru.com%2Fecg%2Fhigh-grade-av-block-0&amp;title=High-grade%20AV%20Block"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Thu, 13 Mar 2014 20:42:48 +0000 Dawn 561 at https://www.ecgguru.com https://www.ecgguru.com/ecg/high-grade-av-block-0#comments