Title: Is this a STEMI? <br/>Author: Leen Alblaihed<br/><a href='http://umem.org/profiles/faculty/1309/'>[Click to email author]</a><hr/><p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-eba5d76c-7fff-7b58-65a4-4b0b184a0ea5"><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">52 yo M with chest pain and shortness of breath, ECG as shown, do you activate cath lab?</span></span></p> <div> <img alt="" src="https://umem.org/files/uploads/content/Leen%20Alblaihed/Picture3.jpg" style="width: 920px; height: 518px;" /></div> <div> <br /> <p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-bcd6550a-7fff-e230-292c-d7795d771461"><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">The posterior descending artery (PDA) supplies the posterior third of the interventricular septum, including the posterior and inferior walls of the left ventricle. The vessel most commonly originates from either the right coronary artery (right dominant), left circumflex artery (left dominant), or both (codominant).</span></span></p> <div> </div> <div> <img alt="" src="https://umem.org/files/uploads/content/Leen%20Alblaihed/Coronary.png" style="width: 511px; height: 285px;" /></div> </div> <p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-1345c687-7fff-6bd1-aff9-74b9862228b4"><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">Posterior MI frequently occurs as an extension of an inferior or lateral infarct. </span><span style="font-size: 11pt; font-family: Arial; font-weight: 700; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">Isolated</span><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"> </span><span style="font-size: 11pt; font-family: Arial; font-weight: 700; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">posterior MI</span><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"> occurs in 3 - 5% of cases (1), and is </span><span style="font-size: 11pt; font-family: Arial; font-weight: 700; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">frequently missed on ECGs</span><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">.</span></span></p> <p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-1345c687-7fff-6bd1-aff9-74b9862228b4"><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">The posterior myocardium is </span><span style="font-size: 11pt; font-family: Arial; font-style: italic; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">not directly visualized</span><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"> on a standard 12 lead ECG, but reciprocal changes of STEMI in the anteroseptal leads (V1- V3) are seen (the posterior electrical activity is recorded from the anterior side of the heart) </span></span></p> <p> </p> <p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-1345c687-7fff-6bd1-aff9-74b9862228b4"><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">If in V1- V3 you see </span></span></p> <p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> </p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-1345c687-7fff-6bd1-aff9-74b9862228b4"><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">* ST segment depression </span></span></p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">* </span></span><span style="font-size: 11pt; white-space: pre-wrap;">Tall R wave</span></p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"><span><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"><span id="docs-internal-guid-1345c687-7fff-6bd1-aff9-74b9862228b4"><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">* Upright T waves </span></span></span></span></span></span></p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> </p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> </p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"><img alt="" src="https://umem.org/files/uploads/content/Leen%20Alblaihed/flip%20ECG.png" style="width: 339px; height: 310px;" /></span></span></p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> </p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span id="docs-internal-guid-e46ffab1-7fff-deb8-9015-07ca1f9a9a9e"><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">Consider posterior MI as a cause. You need to then </span><span style="font-size: 11pt; font-weight: 700; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">obtain an ECG with posterior leads</span><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">. If there is 0.5 mm elevation in any posterior lead this is diagnostic of posterior MI. </span></span></p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> </p> <p dir="ltr" role="presentation" style="list-style-type: disc; font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre;line-height:1.38;margin-top:0pt;margin-bottom:0pt;"> <span><span style="font-size: 11pt; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;"><img alt="" src="https://umem.org/files/uploads/content/Leen%20Alblaihed/post%20leads.png" style="width: 300px; height: 169px;" /></span></span></p>
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<fieldset><legend>References</legend>
<p> <span id="docs-internal-guid-25e3c642-7fff-5534-07d9-4520eb3f0d13"><span style="font-size: 11pt; font-family: Arial; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; vertical-align: baseline; white-space: pre-wrap;">van Gorselen EO, Verheugt FW, Meursing BT, Oude Ophuis AJ. Posterior myocardial infarction: the dark side of the moon. Neth Heart J. 2007 Jan;15(1):16-21</span></span></p> </fieldset>