ECG Guru - Instructor Resources - Junctional escape https://www.ecgguru.com/ecg/junctional-escape en SSS (SICK SINUS SYNDROME) https://www.ecgguru.com/blog/sss-sick-sinus-syndrome <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/sss-sick-sinus-syndrome"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/SSS%20ecgguru.jpg" width="2802" height="1784" 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 does this EKG indicate a sick sinus node? First, we observe a sinus rhythm with a rate just below 60 bpm. Then, there is a pause of approximately 3000 ms, followed not by a sinus beat, but by a junctional escape beat (retrograde/inverted P-wave immediately after the QRS complex). This ECG was recorded at the general practitioner's office, and it can be assumed that no vagal stimulus contributed to the arrhythmia. The same pause recorded in a Holter monitor during the night under the influence of vagal tone, without any other symptoms from the patient, would be evaluated quite differently.</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/660/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 SSS (SICK SINUS SYNDROME) 1/5</option><option value="40">Give SSS (SICK SINUS SYNDROME) 2/5</option><option value="60">Give SSS (SICK SINUS SYNDROME) 3/5</option><option value="80" selected="selected">Give SSS (SICK SINUS SYNDROME) 4/5</option><option value="100">Give SSS (SICK SINUS SYNDROME) 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.7</span></span> <span class="total-votes">(<span >9</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-epjPlBYx7LuACGTEixUCm6WRmWG0ZV6ilXHEQEjz-4Y" /> <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%2Fsss-sick-sinus-syndrome&amp;title=SSS%20%28SICK%20SINUS%20SYNDROME%29"><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> Thu, 03 Aug 2023 07:37:06 +0000 Dr A Röschl 862 at https://www.ecgguru.com https://www.ecgguru.com/blog/sss-sick-sinus-syndrome#comments Inferior-posterior Wall M.I. and AV Dissociation https://www.ecgguru.com/ecg/inferior-posterior-wall-mi-and-av-dissociation <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-posterior-wall-mi-and-av-dissociation"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/IWMI%200019.jpg" width="1800" height="1104" alt="" /></a></div><div class="field-item odd"><a href="/ecg/inferior-posterior-wall-mi-and-av-dissociation"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/IWMI%200019%20for%20Guru%20RS.jpg" width="1800" height="191" 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">At the ECG Guru website, our main goal is to provide quality teaching materials to those who teach ECG interpretation and other cardiac topics.<span style="mso-spacerun: yes;">&nbsp; </span>This ECG offers teaching opportunities for those who teach any level of student.</p><p class="MsoNormal"><strong><span style="color: #00b050;">The patient:</span></strong><span style="color: #00b050;"><span style="mso-spacerun: yes;">&nbsp;&nbsp; </span></span>This ECG was obtained in the Emergency Department from a 54-year-old man who was complaining of severe chest pain and nausea.<span style="mso-spacerun: yes;">&nbsp; </span>His BP was 130/68.</p><p class="MsoNormal"><strong><span style="color: #00b050;">The ECG:</span></strong><span style="color: #00b050;"><span style="mso-spacerun: yes;">&nbsp; </span></span>The rhythm is interesting and not uncommon in the setting of inferior wall M.I.<span style="mso-spacerun: yes;">&nbsp; </span>The atrial rate is about 158 bpm and the P waves are regular. (Marked in red on accompanying rhythm strip).&nbsp; &nbsp;Some P waves are hidden in T waves or ST segments, but we can see fragments of them. The QRS complexes are narrow and mostly regular at a rate of about 56 bpm.<span style="mso-spacerun: yes;">&nbsp; </span>The second QRS on the strip is early, but from the third QRS on, they are regular. The PR intervals are not consistent.<span style="mso-spacerun: yes;">&nbsp; </span>Careful measurements will show that they get shorter and shorter as the recording progresses.<span style="mso-spacerun: yes;">&nbsp; </span>There are more P waves than QRS complexes and there is NO association between the P waves and the QRS complexes, so there is <strong>AV DISSOCIATION</strong>.<span style="mso-spacerun: yes;">&nbsp; </span>One might argue that the first two QRS complexes are conducted from the P waves, with a shorter PR interval with beat #1 and a longer one with beat #2. This would be a short episode of Wenckebach conduction if that is what is happening.<span style="mso-spacerun: yes;">&nbsp; </span>Since we don’t have a strip preceding this one, we can’t be sure.<span style="mso-spacerun: yes;">&nbsp; </span>Clinically, it is smart to address where the patient is now, and that is <strong>SINUS TACHYCARDIA WITH AV DISSOCIATION AND A JUNCTIONAL</strong> <strong>RHYTHM.</strong> Or, it would be fine, after the first two beats, to say the patient is now in COMPLETE AV BLOCK WITH JUNCTIONAL ESCAPE or THIRD-DEGREE AV BLOCK WITH JUNCTIONAL ESCAPE.<span style="mso-spacerun: yes;">&nbsp; </span>We know that this conduction failure is occurring at the level of the AV node because the escape rhythm is junctional.<span style="mso-spacerun: yes;">&nbsp; </span>Blocks at the AV node level are often temporary. <span style="mso-spacerun: yes;">&nbsp;</span>A block lower than this, from the His Bundle through the common branch of the bundle branches, would produce a ventricular escape rhythm.<span style="mso-spacerun: yes;">&nbsp; </span>The important thing, if you are the patient’s health care provider, is that you assess this rate for adequate perfusion.<span style="mso-spacerun: yes;">&nbsp; </span>A heart rate of 57 is almost always sufficient for good perfusion, and is actually preferable for a patient with an ongoing M.I.<span style="mso-spacerun: yes;">&nbsp; </span>Which would you rather have if you were having an M.I., a heart rate of 57 or 158 bpm?<span style="mso-spacerun: yes;">&nbsp; </span><strong><em>Could we say that this AV block has actually HELPED this particular patient?</em></strong><span style="mso-spacerun: yes;">&nbsp; </span>I will happily leave more advanced discussions of this arrhythmia to our commenters.</p><p class="MsoNormal">The <strong>ST segments are noticeably elevated</strong> in Leads II, III, and aVF.<span style="mso-spacerun: yes;">&nbsp; </span>There is <strong>reciprocal ST depression</strong> in Leads I and aVL, and also in the anterior leads. Lead III has a deep, but not wide <strong>Q wave.</strong> This pushes the frontal axis a bit to the left (I and aVL are taller than II). <span style="mso-spacerun: yes;">&nbsp;</span>The T waves in many leads are “hyperacute”.<span style="mso-spacerun: yes;">&nbsp; </span>That is, they are taller than expected, which is a sign of ischemia.<span style="mso-spacerun: yes;">&nbsp; </span>This patient was confirmed to have a <strong>INFERIOR WALL M.I. </strong><span style="mso-spacerun: yes;">&nbsp;</span>Since the RCA supplies the inferior wall and the AV node in the majority of people, it is not surprising that there is an AV block at the level of the AV node. Also, the posterior wall is supplied by the RCA in most people, and the ST depression in the anterior wall with prominent R waves in the septal leads point to posterior M.I.&nbsp; The much less prominent ST depression in V1, as compared to V2, indicates that the right ventricle is sending a signal to V1 to "elevate", while the posterior wall tells V1 to "depress". This results in an ST segment that is cancelled by opposing forces.&nbsp; This would be a good patient to perform V4Right, V7, V8, and V9 on (16-lead ECG).</p><p class="MsoNormal">This is a good ECG to demonstrate what ST segment elevation looks like in acute M.I., as opposed to other causes of STE.<span style="mso-spacerun: yes;">&nbsp; </span>In M.I., we see certain characteristics:</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]--><span style="mso-spacerun: yes;">&nbsp;</span>The STE is found localized in related leads</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]--><span style="mso-spacerun: yes;">&nbsp;</span>The ST segments tend to be straight or curved upward, rather than the normal convex shape</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]--><span style="mso-spacerun: yes;">&nbsp;</span>There is ST depression is leads that are opposite the elevation (See III and aVL)</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]--><span style="mso-spacerun: yes;">&nbsp;</span>There are accompanying signs of M.I., such as T wave inversion, hyperacute T waves, and pathological Q waves. <span style="mso-spacerun: yes;">&nbsp;</span></p><p class="MsoNormal">This ECG can also serve to start a conversation with students about when it is appropriate to treat bradycardia, and when it is best left alone.</p><p class="MsoNormal">EDIT: Dr. Ken Grauer has written a very informative and thought-provoking comment below. If you would like to hear his thoughts on this ECG in more depth, go to his blog at&nbsp;<a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-268-76-mobitz-i-vs-complete-av.html?m=1">https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-268-76-mobitz-i-vs-complete-av.html?m=1</a></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/660/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 Inferior-posterior Wall M.I. and AV Dissociation 1/5</option><option value="40">Give Inferior-posterior Wall M.I. and AV Dissociation 2/5</option><option value="60">Give Inferior-posterior Wall M.I. and AV Dissociation 3/5</option><option value="80" selected="selected">Give Inferior-posterior Wall M.I. and AV Dissociation 4/5</option><option value="100">Give Inferior-posterior Wall M.I. and AV Dissociation 5/5</option></select> <div class="description"><div class="fivestar-summary fivestar-summary-average-count"><span class="average-rating">Average: <span >3.1</span></span> <span class="total-votes">(<span >56</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-LC22L9WoCWQVNPRfS1LURMoG3mRy_bhRB06GzFW36-g" /> <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/stemi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">STEMI</a></div><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/reciprocal-st-changes" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Reciprocal ST changes</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/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/posterior-mi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Posterior M.I.</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/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/escape-rhythm" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Escape rhythm</a></div><div class="field-item even"><a href="/ecg/junctional-escape" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Junctional escape</a></div><div class="field-item odd"><a href="/ecg/right-coronary-artery-occlusion" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Right coronary artery occlusion</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%2Finferior-posterior-wall-mi-and-av-dissociation&amp;title=Inferior-posterior%20Wall%20M.I.%20and%20AV%20Dissociation"><img src="/sites/all/modules/addtoany/images/share_save_256_24.png" width="256" height="24" alt="Share"/></a> </span> </span></li> </ul> Mon, 06 Dec 2021 23:59:10 +0000 Dawn 810 at https://www.ecgguru.com https://www.ecgguru.com/ecg/inferior-posterior-wall-mi-and-av-dissociation#comments An Irregular Bradycardia https://www.ecgguru.com/ecg/irregular-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/irregular-bradycardia"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/12%20Lead%209%2029%20am.jpg" width="1800" height="1078" alt="" /></a></div><div class="field-item odd"><a href="/ecg/irregular-bradycardia"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/12-Lead%2010%2042%20am.jpg" width="2008" height="1166" 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">Thank you to Alikuni Kllany from Toronto for donating these ECGs.&nbsp; They are from a 59-year-old man who has a history of hypertension and depression.&nbsp; Last year, he was on atenolol when he experienced a brief syncopal episode and bradycardia. He was taken off atenolol and started on amlodipine 5 mg.&nbsp; He also takes ramipril 10 mg, atorvastatin 40 mg, and tamsulosin .4 mg.&nbsp; He continues to have bradycardia and dizziness.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">The first ECG shows grouped beating, with repetitive groups of two and three complexes.&nbsp; The P waves are very small, and hard to evaluate.&nbsp; The best place to see them is in the Lead II rhythm strip at the bottom.&nbsp; The rhythm strip is not run concurrently with the 12-Lead, making it even more difficult to evaluate P wave morphology.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">The beats that begin the groups also END a pause.&nbsp; These are junctional escape beats.&nbsp; After the junctional escape beats, the PR intervals vary.&nbsp; This can be explained by <a href="http://ecgguru.com/expert-review/ask-expert-6">RP / PR reciprocity</a>, first described by Mobitz.&nbsp; He demonstrated that the RP interval can affect the next PR interval. Longer RP intervals (slower rate) cause PR shortening.&nbsp; Shorter RP intervals equal longer PR intervals.&nbsp; The P waves are so small, it is difficult to determine whether there is a P wave in the last T wave of each group, which would indicate non-conducted PACs.&nbsp; So, we are left with a sinus pause or sinus exit block (suggested by the timing of the first six beats.&nbsp; We have used red arrows to suggest where the sinus node probably fired.&nbsp; P waves indicate conduction, of course.&nbsp; Lack of P waves, the impulse failed to exit the sinus node.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">There are many mechanisms by which grouped beating can occur.&nbsp; Second-degree AVB, Type I (Wenckebach) comes to mind first.&nbsp; That rhythm in it’s pure form would have a regular sinus rhythm underlying it. &nbsp;&nbsp;Escape-capture bigeminy often occurs with slow rates and junctional escapes, but does not by itself cause “trigeminy”.&nbsp; Sick sinus syndrome can cause all types of chaos in the rhythm.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">The second tracing shows a junctional escape rhythm with no obvious P waves (unsure because the P waves are small, and the 12-Lead is not concurrent with the rhythm strip at the bottom.)&nbsp; It is interesting that the rhythm strip shows four consecutive sinus beats at just under 60 bpm, and with P waves that look different from the P waves on the first ECG. &nbsp;This rate is similar, but not identical to, the sinus rate seen in the first ECG.<span style="font-size: 8pt; line-height: 107%;">&nbsp;</span></p><p class="MsoNormal">The bottom line for the clinician is that this patient, because he is symptomatic, requires a thorough workup.&nbsp; If the cause of the arrhythmias proves to be cardiac in origin, a pacemaker may be required.</p><p class="MsoNormal"><span style="font-size: 8.0pt; line-height: 107%;">&nbsp;</span></p><p>&nbsp;</p><p class="MsoNormal">We welcome any and all discussions regarding this ECG, realizing that P waves are very difficult to evaluate, and that they are probably multi-focal.</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/660/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 An Irregular Bradycardia 1/5</option><option value="40">Give An Irregular Bradycardia 2/5</option><option value="60">Give An Irregular Bradycardia 3/5</option><option value="80">Give An Irregular Bradycardia 4/5</option><option value="100" selected="selected">Give An Irregular Bradycardia 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 >7</span> votes)</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-pPVeQYZzYsgNruKxAZSYzCzMQim7dmxXcB8FhZEjb-U" /> <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/junctional-escape" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Junctional escape</a></div><div class="field-item odd"><a href="/ecg/escape-capture-bigeminy" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Escape-capture bigeminy</a></div><div class="field-item even"><a href="/ecg/r-p-p-r-reciprocity" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">R-P / P-R reciprocity</a></div><div class="field-item odd"><a href="/ecg/sinus-block" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Sinus block</a></div><div class="field-item even"><a href="/ecg/sinus-pause" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Sinus pause</a></div><div class="field-item odd"><a href="/ecg/bradycardia" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Bradycardia</a></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%2Fecg%2Firregular-bradycardia&amp;title=%20%20An%20Irregular%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, 31 Mar 2016 21:05:12 +0000 Dawn 693 at https://www.ecgguru.com https://www.ecgguru.com/ecg/irregular-bradycardia#comments