ECG Guru - Instructor Resources - Interventricular conduction delay https://www.ecgguru.com/ecg/interventricular-conduction-delay en Second-degree AV Block with Left Bundle Branch Block & Lead Reversal https://www.ecgguru.com/blog/second-degree-av-block-left-bundle-branch-block-lead-reversal <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-left-bundle-branch-block-lead-reversal"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/unnamed.jpg" width="3028" height="1899" alt="" /></a></div><div class="field-item odd"><a href="/blog/second-degree-av-block-left-bundle-branch-block-lead-reversal"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/Arm%20leads%20corrected.jpg" width="1800" height="1150" 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>This ECG shows second-degree AV block, Mobitz Type II and an interventricular conduction delay, probably left bundle branch block. The QRS width is about 130 ms, or .13 seconds. The first ECG was run with the right and left arm electrodes reversed, so we cannot demonstrate the usual criteria of LBBB:&nbsp; Wide QRS, Supraventricular rhythm, V1 negative deflection and Leads I and V6 with positive deflections.&nbsp; When the arm electrodes are reversed, Lead I becomes negative, Leads II and III switch places, and Leads aVL and aVR switch places.&nbsp; The second ECG demonstrates the arm electrodes in the correct position, and LBBB criteria met.&nbsp;</p> <p>In second-degree AVB, Type II, there is almost always ECG evidence of fascicular disease such as right bundle branch block or left bundle branch block, as Type II is most often an <strong>intermittent tri-fascicular block.&nbsp; </strong>That is, one or two fascicles of the bundle branches are completely blocked, and the remaining one or two fascicles are intermittently blocked.&nbsp; So, in this case, the left bundle branch (two fascicles) is blocked, and the right bundle branch (one fascicle) is intermittently blocked.&nbsp; At the moment all three fascicles are blocked, there is complete heart block.&nbsp; So, we could say that second-degree AVB, Type II is an <strong>intermittent trifascicular block</strong>, or <strong>intermittent complete AV block</strong>.</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/711/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 Second-degree AV Block with Left Bundle Branch Block &amp;amp; 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//--><!]]> </script></span></li> </ul> Sat, 27 May 2023 07:46:27 +0000 Dr A Röschl 843 at https://www.ecgguru.com https://www.ecgguru.com/blog/second-degree-av-block-left-bundle-branch-block-lead-reversal#comments Wide QRS Complex With First-degree AV Block https://www.ecgguru.com/ecg/wide-qrs-complex-first-degree-av-block <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/wide-qrs-complex-first-degree-av-block"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/IVCD_0.jpg" width="1800" height="983" 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"><strong style="mso-bidi-font-weight: normal;"><span style="color: #00b050;">The Patient:<span style="mso-spacerun: yes;">&nbsp; </span></span></strong>This ECG was taken from a 73-year-old man with a history of heart failure with preserved ejection fraction, severe left ventricular hypertrophy, Type II diabetes, and stage 4 chronic kidney disease.<span style="mso-spacerun: yes;">&nbsp; </span>He also suffered deep vein thrombosis and is on anticoagulation.<span style="mso-spacerun: yes;">&nbsp; </span>He has a recent diagnosis of IgA myeloma.<span style="mso-spacerun: yes;">&nbsp; </span>He presented with a complaint of nausea and vomiting and was found to have a worsening of acute kidney infection.<span style="mso-spacerun: yes;">&nbsp; </span>There was suspicion of renal and cardiac amyloidosis, but the patient refused biopsy to confirm this.<span style="mso-spacerun: yes;">&nbsp; </span>He was started on chemotherapy for multiple myeloma and will be followed as an outpatient.</p><p class="MsoNormal"><strong style="mso-bidi-font-weight: normal;"><span style="color: #00b050;">The ECG:</span></strong><span style="color: #00b050;"><span style="mso-spacerun: yes;">&nbsp; </span></span>The rhythm is <strong style="mso-bidi-font-weight: normal;">sinus</strong> at around 60 bpm, although the rate varies a little at the beginning of the strip.<span style="mso-spacerun: yes;">&nbsp; </span>The QRS complex is wide at .12 seconds, or 120 ms., representing <strong style="mso-bidi-font-weight: normal;">interventricular conduction</strong> <strong style="mso-bidi-font-weight: normal;">delay (IVCD)</strong>.<span style="mso-spacerun: yes;">&nbsp; </span>The PR interval is .32 seconds, or 320 ms. This constitutes <strong style="mso-bidi-font-weight: normal;">first-degree AV block.<span style="mso-spacerun: yes;">&nbsp; </span></strong>There is left axis deviation in the frontal plane and poor R wave progression in the horizontal plane.</p><p class="MsoNormal"><strong style="mso-bidi-font-weight: normal;"><span style="color: #00b050;">Wide QRS:</span></strong><span style="color: #00b050;"><span style="mso-spacerun: yes;">&nbsp;&nbsp; </span></span>When confronted with wide QRS, there are many diagnostic possibilities.<span style="mso-spacerun: yes;">&nbsp; </span>We can rule out a ventricular origin for the beats, as there are P waves consistently before each QRS. There is no history given of the presence of electronic pacemaker, and no obvious spikes.<span style="mso-spacerun: yes;">&nbsp; </span>One of the most common forms of IVCD is <strong style="mso-bidi-font-weight: normal;">left bundle branch block</strong>. In this ECG, V1 has the appearance of LBBB with it’s monophasic, wide QS pattern.<span style="mso-spacerun: yes;">&nbsp; </span>However Leads I and V6 do not have the typical LBBB pattern, which would be broad, positive QRS complexes. By ruling out obvious causes of the conduction delay, we are forced to simply call it “<strong style="mso-bidi-font-weight: normal;">interventricular conduction delay (or defect)”.</strong></p><p class="MsoNormal">Conduction delays below the level of the bundle of His can occur any place along the interventricular conduction system, and can even be a feature of the thickened or dilated left ventricle. One way to pinpoint the area of conduction delay is with electrophysiology studies.</p><p class="MsoNormal">In the past, patients who showed signs of LBBB (a bifascicular block) and first-degree AVB were said to have “trifascicular block”. This term is now outdated, and it is felt that it is preferable to just describe the conduction delays seen. The majority of first-degree AV blocks occur at the AV node level, but in the presence of LBBB, first-degree AVB can represent a conduction defect in the right bundle branch. <span style="mso-spacerun: yes;">&nbsp;</span>Of course, EP studies can make the naming of blocks and conduction delays much more accurate. <a href="https://www.ahajournals.org/doi/pdf/10.1161/01.CIR.43.4.491">A 1971 study</a> explored the occurance and location of first-degree AVB in the setting of interventricular conduction delays.</p><p class="MsoNormal"><strong style="mso-bidi-font-weight: normal;"><span style="color: #00b050;">Left Ventricular Enlargement:</span></strong><span style="color: #00b050;"><span style="mso-spacerun: yes;">&nbsp; </span><span style="mso-spacerun: yes;">&nbsp;</span></span>(a term including hypertrophy and dilatation).<span style="mso-spacerun: yes;">&nbsp; </span>The QRS complexes on this ECG do not meet the <a href="https://litfl.com/left-ventricular-hypertrophy-lvh-ecg-library/">Sokolov-Lyon</a> criteria for LVH, but LVH is not diagnosed by ECG findings, which tend to be less than reliable. This patient’s known history of LVH is presumably confirmed by xray and echocardiogram. The slight <strong style="mso-bidi-font-weight: normal;">ST elevations</strong> in V2, V3, and V4 are typical of wide-complex rhythms, in that they are “discordant” to the QRS direction, and proportional to the size of the QRS.<span style="mso-spacerun: yes;">&nbsp; </span>That is, the ST and T waves will point in a direction opposite that of the QRS, and there will be most notable ST elevation or depression in the leads with the tallest or deepest QRS complexes. For more on evaluation of ST elevation or depression in the presence of broad-complexes, see Dr. Smith’s work on the <a href="http://hqmeded-ecg.blogspot.com/2015/11/validation-of-smith-modified-sgarbossa.html">modified Sgarbossa criteria</a>.</p><p class="MsoNormal">It is safe to say that this unfortunate patient has plenty of clinical history to have the ECG changes seen here, and that there are no acute ECG findings.<span style="mso-spacerun: yes;">&nbsp; </span></p><p class="MsoNormal"><strong style="mso-bidi-font-weight: normal;">We would like to thank Dr. Ahmad Nawid Latifi for sharing this most interesting case with us.<span style="mso-spacerun: yes;">&nbsp; </span>You will find another, similar case from Dr. Latifi <a href="https://ecgguru.com/ecg/instructors-collection-ecg-bifascicular-block-first-degree-avb">here</a>.<span style="mso-spacerun: yes;">&nbsp; </span>Some of the discussion is relevant to both ECGs.</strong></p><p class="MsoNormal"><strong style="mso-bidi-font-weight: normal;"><br /></strong></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/711/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 Wide QRS Complex With First-degree AV Block 1/5</option><option value="40">Give Wide QRS Complex With First-degree AV Block 2/5</option><option value="60" selected="selected">Give Wide QRS Complex With First-degree AV Block 3/5</option><option value="80">Give Wide QRS Complex With First-degree AV Block 4/5</option><option value="100">Give Wide QRS Complex With First-degree AV Block 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 >2</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-RgsSdlYqU2wC9kFi4SMwklzhJuRJ1FWavIAt9D4M6Tc" /> <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/interventricular-conduction-delay" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Interventricular conduction delay</a></div><div class="field-item odd"><a href="/ecg/ivcd" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">IVCD</a></div><div class="field-item even"><a href="/ecg/wide-qrs-complex" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Wide QRS complex</a></div><div class="field-item odd"><a href="/ecg/amyloidosis" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Amyloidosis</a></div><div class="field-item even"><a href="/ecg/smith-modified-sgarbossa-criteria" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Smith Modified Sgarbossa Criteria</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 class="field-item even"><a href="/ecg/left-bundle-branch-block-0" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Left bundle branch block</a></div><div class="field-item odd"><a href="/ecg/lbbb" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">LBBB</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%2Fwide-qrs-complex-first-degree-av-block&amp;title=Wide%20QRS%20Complex%20With%20First-degree%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> Fri, 07 Jun 2019 20:48:29 +0000 Dawn 769 at https://www.ecgguru.com https://www.ecgguru.com/ecg/wide-qrs-complex-first-degree-av-block#comments