ECG Guru - Instructor Resources - Proximal occlusion of LAD https://www.ecgguru.com/ecg/proximal-occlusion-lad en Large Anterior Wall M.I. and Effect of Lead Reversal https://www.ecgguru.com/ecg/large-anterior-wall-mi-and-effect-lead-reversal <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/large-anterior-wall-mi-and-effect-lead-reversal"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/Prox%20LAD%20MI%201%20edit.jpg" width="2227" height="1287" alt="" /></a></div><div class="field-item odd"><a href="/ecg/large-anterior-wall-mi-and-effect-lead-reversal"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/Prox%20LAD%20MI%202_0.jpg" width="1860" height="1230" alt="" /></a></div><div class="field-item even"><a href="/ecg/large-anterior-wall-mi-and-effect-lead-reversal"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/Cath%20lab%20photos%20before%20and%20after_0.jpg" width="1601" height="738" 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>EDIT: Please refer to the comments below this text. The second ECG in this series shows unexpected QRS and ST-T morphology changes, which I tried to explain by way of the patient's long anterior descending coronary artery. However, Dave Richley, who is a very well-known cardiac physiologist and ECG Guru took the time to analyze these morphologies and realize they can be explained by an inadvertent ECG LEAD MISPLACEMENT. This patient does have a proximal lesion of the LAD, proven and repaired in the cath lab. But the inferior wall does not have the injury it appears to have in this second ECG. Thanks to Dave for reminding us to slow down and look closely when things don't look "right".</strong></p><p class="MsoNormal"><strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;">The Patient:</span></strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;"><span style="mso-spacerun: yes;">&nbsp;&nbsp; </span></span><span style="font-size: 10.0pt; line-height: 107%;">These two ECGs, taken 26 minutes apart, were obtained from a 50-year-old man who complained of sudden onset of chest pain.<span style="mso-spacerun: yes;">&nbsp; </span>He denied history of coronary artery disease. He was Covid-positive, and the rest of his medical history was unremarkable.</span></p><p class="MsoNormal"><strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;">ECG No. 1:<span style="mso-spacerun: yes;">&nbsp; </span></span></strong><span style="font-size: 10.0pt; line-height: 107%;">This ECG was obtained by paramedics enroute to the hospital.<span style="mso-spacerun: yes;">&nbsp; </span>For your beginner-level students, it will be easy to demonstrate the large ST elevations in V3 through V6. The machine’s measurements at the bottom confirm that this ECG meets any field criteria for ST elevation M.I. “STEMI”.</span></p><p class="MsoNormal"><span style="font-size: 10.0pt; line-height: 107%;">But there is so much more to see! Taking a methodical approach, and starting with rate and rhythm, we see <strong>sinus bradycardia </strong>at 57 bpm. Intervals and frontal plane axis are within normal limits. R wave progression in the chest leads is stalled in V1- V3 due to loss of initial r waves (narrow QS). The transition to positive deflections in V4 – V6 is abrupt.<span style="mso-spacerun: yes;">&nbsp; </span>These q waves in the V1 and V2 appear narrow, but V3 appears to have a Q wave that is almost wide enough to be considered pathological.<span style="mso-spacerun: yes;">&nbsp; </span>Narrow Q waves may be a transient sign of injury, while wide ones (&gt;40 ms) are an ECG sign of necrosis. </span></p><p class="MsoNormal"><span style="font-size: 10.0pt; line-height: 107%;">A very visible finding on this ECG is the <strong><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4500486/">hyperacute T waves</a></strong>. Hyperacute T waves are defined by comparison to the patient’s normal T waves, if possible. But a general description is broad-based, symmetrical T waves that are unusually tall in comparison to the QRS complex and to the patient’s previous T waves. In this tracing, we see hyperacute T waves in just about all leads.<span style="mso-spacerun: yes;">&nbsp; </span>Hyperacute T waves are a very early sign of subendocardial ischemia in a patient with coronary artery occlusion, and the sign doesn’t last long.</span></p><p class="MsoNormal"><span style="font-size: 10.0pt; line-height: 107%;">This patient is already progressing to the next ECG stage of ischemia and injury:<span style="mso-spacerun: yes;">&nbsp; </span><strong>ST segment elevation</strong>.<span style="mso-spacerun: yes;">&nbsp; </span>There is elevation in V2 through V6, I and aVL, and very slightly in Leads II and aVF.<span style="mso-spacerun: yes;">&nbsp; </span>In addition to this J point elevation, many ST segments have a flat, horizontal shape, which is an abnormal sign, indicative of ischemia. Leads III and aVF are good examples of this abnormal ST segment shape.<span style="mso-spacerun: yes;">&nbsp;</span></span><span style="font-size: 10pt;">V1 has </span>an inverted T wave<span style="font-size: 10pt;">.</span><span style="mso-spacerun: yes;">&nbsp; V2 shows the T wave transition to upright.&nbsp;&nbsp;</span></p><p class="MsoNormal"><span style="font-size: 13.3333px;">&nbsp;</span></p><p class="MsoNormal"><strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;">ECG No. 2:</span></strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;"><span style="mso-spacerun: yes;">&nbsp; </span></span><span style="font-size: 10.0pt; line-height: 107%;">This ECG was taken in the Emergency Department, 26 minutes after the first one.<span style="mso-spacerun: yes;">&nbsp; </span>The rate and intervals have not changed much.<span style="mso-spacerun: yes;">&nbsp; </span>The QRS duration has lengthened by .04 seconds, the QTc has prolonged by 26 ms.<span style="mso-spacerun: yes;">&nbsp; </span>The axis has shifted slightly to the left, but still within normal limits.</span></p><p class="MsoNormal"><span style="font-size: 10.0pt; line-height: 107%;">Leads II, III, and aVF (inferior wall) have lost voltage and gained quite noticeable ST segment elevation.<span style="mso-spacerun: yes;">&nbsp; </span>Lead III has a narrow Q wave and biphasic T wave, which are new developments.<span style="mso-spacerun: yes;">&nbsp; </span>Leads I and aVL are now so influenced by the STE in the inferior wall, they show ST depression, which is reciprocal to the elevation in the inferior leads.&nbsp;<span style="mso-spacerun: yes;">&nbsp;</span>It has obliterated the ST elevation in those leads, but we remember it is there!</span></p><p class="MsoNormal"><span style="font-size: 10.0pt; line-height: 107%;">Lead V1 has developed concave-down elevation (the “frown”), and has a narrow Q wave.<span style="mso-spacerun: yes;">&nbsp; </span>V2 and V3 have enhanced ST elevation, and the Q waves in those leads have widened to greater than 40 ms. <span style="mso-spacerun: yes;">&nbsp;</span>Leads V5 and V6 have less ST elevation, possibly influenced by simultaneous reciprocal ST depression.<span style="mso-spacerun: yes;">&nbsp; </span>We can say that this M.I. has definitely progressed, and it is <strong>VERY large</strong>.</span></p><p class="MsoNormal"><strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;">Follow Up:</span></strong><span style="font-size: 10.0pt; line-height: 107%; color: #00b050;"><span style="mso-spacerun: yes;">&nbsp; </span></span><span style="font-size: 10.0pt; line-height: 107%;">The patient was taken very quickly to the cath lab, where it was found that he had a proximal LAD occlusion from a fresh clot.<span style="mso-spacerun: yes;">&nbsp; </span>The other arteries showed no signs of CAD.<span style="mso-spacerun: yes;">&nbsp; </span>You might be thinking, “that explains the changes in the chest leads (anterior wall), but how is the inferior wall involved in this M.I.?”<span style="mso-spacerun: yes;">&nbsp; </span>This patient is one of the many people (up to 79% of the population) who has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6528515/">wrap-around LAD</a>.<span style="mso-spacerun: yes;">&nbsp; </span>That is, it perfuses the apex of the left ventricle.<span style="mso-spacerun: yes;">&nbsp; </span>Approximately one fourth of the population has an LAD that wraps around <strong>more than one fourth</strong> of the inferior wall. This type of LAD predicts additional risk of adverse clinical outcomes for M.I. patients because of the large amount of territory covered by this wrap-around artery.<span style="mso-spacerun: yes;">&nbsp; </span>The patient arrived in the cath lab before his troponin levels went up, and had a successful procedure.<span style="mso-spacerun: yes;">&nbsp; </span>He is lost to follow up after that.<span style="mso-spacerun: yes;">&nbsp;&nbsp;</span></span></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/489/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 Large Anterior Wall M.I. and Effect of Lead Reversal 1/5</option><option value="40">Give Large Anterior Wall M.I. and Effect of Lead Reversal 2/5</option><option value="60">Give Large Anterior Wall M.I. and Effect of Lead Reversal 3/5</option><option value="80" selected="selected">Give Large Anterior Wall M.I. and Effect of Lead Reversal 4/5</option><option value="100">Give Large Anterior Wall M.I. and Effect of Lead Reversal 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 >67</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-dOmQkmxgh4PZqJaOmzZnUViBJpKo7gl7Qe6eLVZHP1M" /> <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/lead-reversal" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Lead reversal</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/awmi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">AWMI</a></div><div class="field-item odd"><a href="/ecg/iwmi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">IWMI</a></div><div class="field-item even"><a href="/ecg/lateral-mi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Lateral M.I.</a></div><div class="field-item odd"><a href="/ecg/anterior-mi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Anterior M.I.</a></div><div class="field-item even"><a href="/ecg/proximal-occlusion-lad" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Proximal occlusion of LAD</a></div><div class="field-item odd"><a href="/ecg/hyperacute-t-waves" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Hyperacute T waves</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></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%2Flarge-anterior-wall-mi-and-effect-lead-reversal&amp;title=Large%20Anterior%20Wall%20M.I.%20and%20Effect%20of%20Lead%20Reversal%20"><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, 23 May 2022 21:52:02 +0000 Dawn 814 at https://www.ecgguru.com https://www.ecgguru.com/ecg/large-anterior-wall-mi-and-effect-lead-reversal#comments Acute Anterior-Lateral Wall M.I. https://www.ecgguru.com/ecg/acute-anterior-lateral-wall-mi <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/acute-anterior-lateral-wall-mi"><img typeof="foaf:Image" src="https://www.ecgguru.com/sites/default/files/AW120%20%20ON%20Site.jpg" width="1800" height="509" 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 week's ECG is from a 47-year-old man who experienced a sudden onset of chest pain while mowing his lawn. &nbsp;He went on to suffer a cardiac arrest and was resuscitated. &nbsp;We do not have long-term followup on his outcome.</p><p>The experienced person will have no difficulty identifying a large acute antero-lateral wall M.I. &nbsp;There are massive <strong>ST segment elevations in Leads V1 through V6,</strong> reflecting acute injury from the septal side of the anterior wall (patient's right) to the anterior-lateral wall (patient's left). &nbsp;There are also<strong> ST elevations in Leads I and aVL</strong>, reflecting the high lateral wall. &nbsp;This indicates, and was confirmed in the cath lab, that the lesion is proximal - at or above the bifurcation of the left anterior descending artery and the circumflex artery. &nbsp;The ST depressions in the inferior wall leads (II, III, and aVF) likely represent reciprocal changes. &nbsp;You will note that the ST depression in Lead III has a very similar shape to the ST elevation in Lead aVL.</p><p>More bad news for this patient is the presence of&nbsp;<strong>pathological Q waves&nbsp;</strong>in Leads V1 through V4, reflecting transmural death of the myocardial tissue. &nbsp;This causes akinesis and poor left ventricular function. &nbsp;In addition, it's not only muscle tissue that dies, but also electrical structures , such as bundle branches. &nbsp; Papillary muscles can be infarcted, causing valve malfunction. &nbsp;And remember, all patients who have ST elevation due to acute injury are vulnerable to ventricular tachycardia and ventricular fibrillation, due to re-entry mechanisms in injured tissue. &nbsp;&nbsp;</p><p>This ECG will allow instructors to discuss with their students:</p><p>* &nbsp;which leads reflect changes from which parts of the heart</p><p>* &nbsp;what the ECG signs of acute M.I. are</p><p>* &nbsp;the pathophysiology of pathological Q waves</p><p>* &nbsp;the effect of damage to various parts of the heart on the patient's condition and symptoms</p><p>This "classic" M.I. pattern should be taught to all health care professionals who work in settings where ECG is used.</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/489/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 Acute Anterior-Lateral Wall M.I. 1/5</option><option value="40">Give Acute Anterior-Lateral Wall M.I. 2/5</option><option value="60">Give Acute Anterior-Lateral Wall M.I. 3/5</option><option value="80">Give Acute Anterior-Lateral Wall M.I. 4/5</option><option value="100" selected="selected">Give Acute Anterior-Lateral Wall M.I. 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 >12</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-s9UGYnLJbTFUoSr6n7nI9daPdS2yy4bbJgxMb4FyOPk" /> <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/stemi" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">STEMI</a></div><div class="field-item odd"><a href="/ecg/anterior-wall-mi-5" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Anterior wall M.I.</a></div><div class="field-item even"><a href="/ecg/proximal-occlusion-lad" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Proximal occlusion of LAD</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/pathological-q-waves" typeof="skos:Concept" property="rdfs:label skos:prefLabel" datatype="">Pathological Q waves</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%2Facute-anterior-lateral-wall-mi&amp;title=Acute%20Anterior-Lateral%20Wall%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> Fri, 25 Apr 2014 20:01:47 +0000 Dawn 568 at https://www.ecgguru.com https://www.ecgguru.com/ecg/acute-anterior-lateral-wall-mi#comments