CARDIOVASCULAR-RESPONSE AND SEIZURE DURATION AS DETERMINED BY ELECTROENCEPHALOGRAPHY DURING UNILATERAL ELECTROCONVULSIVE-THERAPY

The effect of pulse unilateral electroconvulsive therapy (ECT) on hear t rate, blood pressure and the product of heart rate and systolic bloo d pressure, an index of myocardial oxygen consumption, was studied dur ing 48 ECT sessions in 7 patients with major depression. Intraindividu ally, hyperventilation-induced hypocapnia compared with normocapnia ma rkedly augmented the ECT-induced increase in heart rate (47% vs 28%) a nd the product of heart rate and systolic blood pressure (82% vs 60%). Over all ECT seizures, the maximum and increase in heart rate and the product of heart rate and systolic blood pressure were significantly correlated with seizure duration as determined by electroencephalograp hy. However, significant correlations were only present for the seizur es during hypocapnia and not during normocapnia. Combining measures of magnitude and length of ECT-induced tachycardia to motor responses ma y increase the potential for clinical seizure evaluation.