What Do You Think 61

This ECG was presented during coronary care unit rounds and came from a patient in cardiogenic shock and right ventricular failure.

What do you think?

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The rhythm is sinus tachycardia (red arrows), rate 130 bpm and atrial ectopics (blue arrow).

There is evidence of an acute inferiorSTEMI (ST elevation myocardial infarction) with ST elevation and developing Q waves in leads II, III and aVF (red highlight). Note that the most prominent ST segment elevation is in lead III.

There are also reciprocal changes in the antero-lateral leads I, aVL, V2 to V6 (yellow highlight).

Although the signs are subtle, there is a right bundle branch block (120 ms) with an rsR in V1 and a broad Swave in V6.

There is another feature that makes this ECG unusual.

ST elevation in V1 and markedST depression in V2, V3.

This combination with an evolving acute inferior myocardial infarction is diagnostic of right ventricular infarction.

Aright ventricular infarct is rarely recognised on the ECG as the features are subtle and hence not recognised.

These include:

• ‍An evolving acute inferior infarct. Although a right ventricular infarct can be an isolated event, it is usually diagnosed in the presence of an acute inferior infarct.‍
• ST elevation V1. This is the only lead in a routine12-lead ECG which looks at the right ventricle. In this situation, a V4R recording would be even more helpful.‍
• Marked ST depression in V2, V3. The features are very specific for right ventricular infarction when combined with ST elevation in V1/V4R. ‍
• LeadIII lies on the right, whereas lead II lieson the left. Lead III is therefore closer to the right ventricle and with right ventricular infarction, the ST elevation is most pronounced in this lead.‍
• Marked sinus tachycardia reflects the low left ventricular output created by the right ventricular infarction with peripheral pooling and a low systemic blood pressure which is treated with fluid loading. Vasodilators such as nitrates are contraindicated as they exacerbate the pooling and low blood pressure.
• It is not surprising that the infarction also involves the right bundle branch resulting in a right bundle branch block.

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Harry Mond