Effect of electroconvulsive therapy on the electrocardiogram and echocardiogram

Although electrocardiographic (ECG) ST segment depression is commonly induced by electroconvulsive therapy (ECT) for depression, it is unknown whether this reflects segmental myocardial ischemia, as is true under most circumstances, or a direct effect of central nervous system stimulation on cardiac repolarization in the absence of ischemic left ventricular regional wall motion abnormalities. We evaluated the association between ECG changes and left ventricular regional wall motion abnormalities detected by the echocardiograms performed before and after ECT in 11 patients. Immediately after ECT, three patients' ECGs revealed 1-mm downsloping or horizontal ST segment depression, one had a nonspecific ECG change (peaked T waves), and the ECG remained normal in seven. All patients had normal baseline echocardiograms. After ECT, at a time when the product of arterial blood pressure and heart rate was 100% above baseline values, five patients developed new left ventricular regional wall motion abnormalities that were confined to hypokinesia; no patient developed myocardial infarction or angina after ECT. Three patients with regional wall motion abnormalities developed ECG ST segment depression after ECT (sensitivity 60%), one had a nonspecific ECG change (peaked T waves), and the ECG of one patient remained normal. In conclusion, ECT may induce ECG changes with simultaneous regional wall motion abnormalities at a time when arterial blood pressure and heart rate are markedly elevated, findings that are highly suggestive of "demand" myocardial ischemia. In this small series, ECG or echocardiographic abnormalities did not predict clinical cardiac morbidity.