Response to exercise in patients taking psychotropic drugs. Arrhythmias and the QT interval (QT wave peak)

Abstract

Psychotropic drugs may prolong the QT interval, potentially predisposing to ventricular arrhythmias and/or sudden death. Exercise prescribed as therapy for depression may also prolong the QT interval and augment arrhythmia risk. To determine QT-interval (QT wave peak or QTPK) response to exercise in patients receiving psychotropic drugs [neuroleptics, tricyclic antidepressants and Li2CO3], treadmill exercise testing was performed on 20 mentally competent psychiatric inpatients clinically free of heart disease. The 24-h ambulatory ECG were performed within 1 day of exercise testing to detect arrhythmias during routine daily activities. Exercise test results for psychiatric patients were compared with those of normal subjects receiving no medication. Separate regression lines relating heart rate of QTPK interval, calculated for each group, showed no significant difference. No serious arrhythmias occurred during routine daily activities or exercise. Patients without heart disease taking psychotropic drugs had appropriate QTPK-interval shortening with exercise.