Myocardial Dysfunction in Silent Myocardial Ischemia as Demonstrated by Ambulatory Radionuclide Left Ventricular Function Studies

Prognostic implications of mental stress-induced silent left ventricular dysfunction in patients with stable angina pectoris

Thirty patients with stable angina pectoris and ischemia on stress perfusion imaging underwent continuous ambulatory left ventricular (LV) function monitoring. Mental stress was induced by mental arithmetic. Fifteen patients developed transient LV dysfunction during mental arithmetic. Patients were followed for 2 years for adverse cardiac events. Twelve patients had cardiac events over 1 year (myocardial infarction in 4, and unstable angina in 8). Nine of 15 patients (60%) with and only 3 of 15 (20%) without mental stress-induced LV dysfunction developed cardiac events (p = 0.025). A higher proportion of patients with cardiac events were taking beta blockers (p = 0.01) and had lower resting heart rates (p = 0.002) than those without cardiac events. There was no difference in the baseline characteristics between the groups of patients with and without cardiac events. At 2-year follow-up, 10 of 15 patients (67%) with mental stress-induced LV dysfunction had adverse events compared with only 4 of 15 (27%) with no mental stress-induced LV dysfunction (p = 0.025). Thus, in this cohort of patients with stable angina pectoris, mental stress-induced LV dysfunction was associated with higher cardiac events on follow-up. The exact mechanism of this association is not clear. Mental stress may be a trigger for adverse cardiac events in these patients. Transient LV dysfunction in response to mental stress may be a marker of abnormal cardiovascular reactivity to emotional and psychological stimuli in patients with coronary artery disease and may be useful for risk stratification.