ECG Guru - Instructor Resources - Subtle ST changes https://www.ecgguru.com/ecg/subtle-st-changes en 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/662/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 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" name="op" value="Rate" /><input type="hidden" name="form_build_id" value="form-EBMR-PhZ0DxfF7TCT-RtWLxV3xnOMk_n55S_9bk6KRE" /> <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_1"> <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> <script type="text/javascript"> <!--//--><![CDATA[//><!-- if(window.da2a)da2a.script_load(); //--><!]]> </script></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 Subtle ST Changes https://www.ecgguru.com/ecg/subtle-st-changes-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/subtle-st-changes-0"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AW121%2065%20F%20CP%20Subtle.jpg" width="1800" height="865" 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 is from a 65-year-old woman who presented to the Emergency Department with a complaint of chest pain.&nbsp; We have no other clinical information.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">There are several subtle, but real, abnormalities on the ECG that should be evaluated in conjuction with her clinical situation.&nbsp; This is a good ECG to discuss with your more advanced students who have mastered recognition of blatant ST elevation M.I. (STEMI).&nbsp; But, let’s start with what is NORMAL here.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal"><strong>NORMAL FEATURES &nbsp; &nbsp; &nbsp; &nbsp;</strong><span style="font-size: 13.008px; line-height: 1.538em;">The normal findings are:</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; </span><span style="font-size: 13.008px; line-height: 1.538em;">normal sinus rhythm at about 68 bpm.</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; The rhythm is regular without ectopy.&nbsp;</span><span style="font-size: 13.008px; line-height: 1.538em;">The intervals are within normal limits.</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; </span><span style="font-size: 13.008px; line-height: 1.538em;">The frontal plane axis is normal. The T waves are all upright.</span><span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal"><strong>ABNORMAL FEATURES &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</strong><span style="font-size: 13.008px; line-height: 1.538em;">There is subtle ST segment elevation in Leads V1 through V3, and in I and aVL.</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; </span><span style="font-size: 13.008px; line-height: 1.538em;">The shape of the ST segments is concave upward, or normal.</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; </span><span style="font-size: 13.008px; line-height: 1.538em;">In a young, asymptomatic patient, we probably would not be at all concerned about this amount of ST elevation.</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; </span><span style="font-size: 13.008px; line-height: 1.538em;">However, this is an older patient with chest pain. In the chest leads, the R wave progression is interrupted, as the QRS goes abruptly from negative to positive in Lead V3.</span><span style="font-size: 13.008px; line-height: 1.538em;">&nbsp; </span><span style="font-size: 13.008px; line-height: 1.538em;">This could be due to loss of r waves ( pathological Q waves forming) in V1 and V2 lead placement, or something else.</span><span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">In addition, the inferior leads (II, III, and aVF) show ST flattening, with ST depression in Lead III.&nbsp; Probably the best way to approach such subtle changes in a symptomatic patient is to repeat the ECG frequently while initiating evaluation and treatment of the chest pain.&nbsp; Often, ST segments will change rapidly during an ischemic episode.&nbsp; Lead aVL appears to have a pathological Q wave, but that lead sometimes has a septal q wave, which is normal. Having a prior ECG for comparison is also very helpful for differentiating acute changes.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal"><strong>TEACHING OPPORTUNITIES &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;</strong><span style="font-size: 13.008px; line-height: 1.538em;">This tracing can help you teach students that not all cardiac patients will present with flagrant STEMIs, and we much learn to see subtle abnormalities and consider them in light of clinical features – history, symptoms, labs, and ECG changes.</span></p><p class="MsoNormal">&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/662/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 Subtle ST Changes 1/5</option><option value="40">Give Subtle ST Changes 2/5</option><option value="60">Give Subtle ST Changes 3/5</option><option value="80">Give Subtle ST Changes 4/5</option><option value="100" selected="selected">Give Subtle ST Changes 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >4.4</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-xDJGxEbi45bpHxR3c1QfFHiztge8QflAut7jb-cZ3fg" /> <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/st-elevation" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">ST elevation</a></div><div class="field-item odd"><a href="/ecg/stemi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">STEMI</a></div><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></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%2Fsubtle-st-changes-0&amp;title=%20Subtle%20ST%20Changes"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Tue, 12 Apr 2016 01:18:12 +0000 Dawn 694 at https://www.ecgguru.com https://www.ecgguru.com/ecg/subtle-st-changes-0#comments