Unipolar ventricular electrogram in the diagnosis of right ventricular ischemic injury.

Unipolar ventricular electrograms were recorded in the right ventricular apical area in five patients with clinical, hemodynamic features of the right ventricular infarction. The intracavitary potential exhibited a downward displacement of the ST segment (1.5 mV). This significant negative current of injury in the ventricular electrogram is consistent with ischemic injury of the free right ventricular wall in the area subtended by the intracavitary exploring electrode. We suggest that ventricular electrographic recordings be performed in patients who present with acute inferior wall infarction requiring temporary electrode catheter pacing for serious AV conduction disturbances. The presence of a significant downward ST segment displacement (1.5 mV) provides further support and an electrical criterion for right ventricular ischemic injury.