ECG Review-An Abnormal ECG in an Asymptomatic Man

Clinical Scenario: The ECG shown in the Figure was obtained from a completely asymptomatic 56-year-old man. How would you interpret this ECG? What would you suspect the patient to have (have had)?

Interpretation: There is a normal sinus rhythm at a rate of 85 beats/minute. The PR interval is normal. However, everything else on this tracing is distinctly abnormal. The QRS complex is clearly prolonged in a pattern consistent with bifascicular block. Specifically, the qR complex in lead V1 with tall R wave and the wide terminal S waves in leads I and V6 are consistent with right bundle branch block (RBBB). In addition, the markedly deepened S wave component of the QRS complex in lead I, together with relatively positive complexes in the inferior leads, is consistent with the rightward axis of left posterior hemiblock (LPHB). The relatively tall and peaked P waves in lead II, and biphasic P wave in lead V1 with peaked initial component and deep negative terminal component are consistent with biatrial enlargement. Small but definite Q waves are seen both in inferior and anterior precordial leads (the latter most likely responsible for loss of the rsR’ pattern in lead V1). Finally, ST segment and T wave morphology is abnormal: The upright T wave in lead V1 suggests a primary T wave change (the T wave in lead V1 with RBBB is usually directed opposite to the tall terminal R wave)—and beginning T wave inversion in leads V3 and V5 suggests an ischemic process.

In view of the fact that this patient is completely asymptomatic, the changes on this ECG are probably not acute. However, biatrial enlargement, bifascicular block, inferior and anterior Q waves, and abnormal ST-T wave changes all strongly suggest a cardiomyopathy that is most likely ischemic in etiology from prior silent infarction(s). At the least, further evaluation with an echocardiogram would seem warranted.