We analysed a group of 35 consecutive patients with acute myocardial infarction-23 of the inferior, 12 of the anterior wall-who needed temporary pacing for bradycardiac arrhythmias. We observed in three patients ventricular tachycardias induced by pacemaker stimuli falling onto the vulnerable part of the cardiac cycle due to improper sensing. All three had an inferior myocardial infarction involving the right ventricle. Because the pacemaker electrode in this condition lies in the vicinity of the infarcted myocardium sensing problems occur more frequently and re-entry tachycardias can be triggered more easily. It represents a possible risk of pacemaker treatment in his group of patients who, on the other hand, often need cardiac pacing in the acute phase following the development of transient AV-block.