The role of psychologic stress in the genesis of lethal arrhythmias in patients with coronary artery disease.

To investigate the influence of psychologic stress on the electrophysiology of the heart and the genesis of cardiac arrhythmias, programmed ventricular stimulation was performed in 19 patients with recent uncomplicated myocardial infarction (37 +/- 10 days after the acute episode) during control conditions and during mental arithmetic. Psychological assessment showed a normal profile in all subjects. During mental stress, blood pressure increased (from 147 +/- 16/96 +/- 9 to 171 +/- 16/106 +/- 8 mmHg, P less than 0.001), and the mean ventricular refractory period decreased by 8 ms (1-3 extrastimuli P less than 0.05-0.001). Unsustained ventricular tachycardia (greater than or equal to 6 beats) was induced in 2 and 7 patients during control and during stress stimulation respectively (P less than 0.05). Ventricular fibrillation was provoked by double (1 patient) and triple (1 patient) extrastimuli during stress. In conclusion mental stress can induce measurable cardiac electrophysiological modifications in uncomplicated postinfarct patients and such modifications may favour the appearance of life-threatening arrhythmias.