Myocardial Infarction with Dual Culprit Lesions

A 59-year-old man without prior cardiac history presented with three hours of severe upper sternal chest pressure that radiated to his throat, which he described as “strangulating.” An ECG was obtained, and is shown here. It demonstrates a sinus rhythm at rate of approximately 75 bpm. The PR and QT intervals are normal. There is concerning 1 mm of ST-elevation in V5 and V6 with ST-segment depression in V2 and V3, suggestive of a posterior myocardial infarction. The initial ECG was concerning for 1 mm of ST-elevation in V5 and V6 with ST-segment depression in V2 and V3. This is suggestive of a posterior myocardial infarction, prompting us to obtain a posterior ECG. This can be done by removing the leads for V4 thru V6 and placing them on the back at the same thoracic level. The lead for V7 is placed more posterior than V6, V8 is placed in line with the tip of the scapula, and V9 is placed in the left paraspinal region. The other leads remain the same. These leads generally record lower voltage levels because the distance to the heart is greater for them. The patient’s posterior ECG was obtained about 10 minutes after the initial ECG.   The QRS complex and T-wave does indeed have low voltage in leads V7 thru V9, but the T-wave is large in proportion to the R-wave. These hyperacute T-waves can be seen shortly after occlusion of an artery and after reperfusion. No ongoing ST-elevation of the posterior leads is present as was seen in V5 and V6. Interestingly, the ...
Source: Spontaneous Circulation - Category: Emergency Medicine Tags: Blog Posts Source Type: blogs