Conduction disturbances between a pacemaker electrode and the myocardium in right ventricular infarction.

Rate dependent first degree block, which was followed by a complete block, between a pacemaker electrode and the ventricular myocardium, was observed in a patient with inferior myocardial infarction. These conduction disturbances which occurred during pacing at the postero-basal wall of the right ventricle and not during pacing at the apex, suggested that the posterior part of the right ventricle was damaged. This hypothesis was supported by hemodynamic findings which indicated a right ventricular infarction.