Induction of myocardial ischaemia by mental stress in coronary heart disease.

To define the importance of mental stress in the genesis of myocardial ischaemia in patients with coronary heart disease, we studied 50 cases in whom ischaemia was provoked by a variety of mental stress tasks: arithmetic calculations, reading aloud and emotionally arousing speech. The haemodynamic responses were compared to those induced by exercise stress tests in 38 of these patients. Thirty four of the 50 patients tested (68%) developed electrocardiographic evidence of ischaemia during mental stress tasks as compared to 29 to 38 patients (76.3%) undergoing treadmill stress test (p > 0.05). The personally relevant emotionally arousing speech task caused more frequent changes as compared to maths and reading tasks (p < 0.01), although reading task provoked more ischaemia than maths task (p < 0.01). The magnitude of ischaemic changes was similar for emotionally arousing speech and treadmill test. On comparison of haemodynamic changes in 38 patients in whom both exercise and speech tasks were performed, it was seen that ischaemic changes occurred at lower heart rates (p < 0.01), lower peak systolic blood pressure (p < 0.01) and a lower double product (p < 0.01) during emotionally arousing speech task than during treadmill stress test.