[Runaway pacemaker caused by the defect of a Lem-Dynacor pacemaker (author's transl)]

Caused by the defect of a Lem-Dynacor pacemaker, a critical diminution of the period time till 20 ms developed. Fortunately, ventricular fibrillation did not occur because of diminution of the impulse amplitude beyond the threshold value of ventricular stimulation. Recognition of the defect with the ECG is possible if considered. It is easy to confuse with overlapping of alternating current.