Alterations in P wave duration and dispersion in depressive patients following electroconvulsive therapy

Electroconvulsive therapy (ECT) consists of controlled convulsive seizure by electric stimulation of the brain. Although various electrocardiographic (ECG) changes have been reported during ECT, atrial conduction has not been studied extensively. The aim of the present study was to assess the effects of ECT on systemic arterial blood pressure and ECG parameters (P wave duration, P wave dispersion and heart rate).

Thirty depressive patients undergoing ECT were included. Echocardiographic examination was performed on all patients before ECT sessions to exclude systolic heart failure and diastolic dysfunction which may affect P wave duration and dispersion. Twelve-lead ECG records were obtained before the first ECT and after the third session of ECT. Blood pressure was measured before and after convulsive therapy session.

Compared to baseline values, maximum P wave duration (99.3 ± 14.6 to 111.3 ± 8.2 ms, P=.001), P wave dispersion (50 ± 14.8 to 63.3 ± 10.3 ms, P=.001), and systolic (110.7 ± 12 to 116 ± 12.2 mmHg, P=.043) and diastolic blood pressures (70.7 ± 9.4 to 75.3 ± 8.2 mmHg, P=.028) were significantly increased after convulsive therapy session.

We proposed that ECT alone or in combination with atypical antipsychotics or antidepressants may influence atrial conduction as evidenced by the significantly prolonged maximum P wave duration and P wave dispersion. Longer-term follow-up of patients undergoing ECT may be appropriate to evaluate the possible long-term outcomes of our short-term results.