Percussion Pacing as a Rescue for Peri-Stimulus Asystole During Electroconvulsive Therapy.

Electroconvulsive therapy (ECT) can provoke a brief parasympathetic surge, commonly causing transient sinus bradycardia or a short sinus pause. Most events last only seconds and resolve without intervention. Rarely, however, bradyarrhythmia or asystole may persist long enough to threaten cerebral perfusion, requiring anesthesia teams to respond immediately. We report the case of a male patient with treatment-resistant major depressive disorder who underwent bilateral ECT under methohexital and succinylcholine. Baseline sinus bradycardia was present at 47 beats per minute. Immediately after the ECT stimulus, the monitor demonstrated high-grade atrioventricular block that progressed to ventricular asystole with a flat plethysmographic waveform. Within 10 to 15 seconds, while glycopyrrolate and epinephrine were being prepared, percussion pacing was delivered using the ulnar aspect of a closed fist over the left lower sternal edge at ∼ the fourth-to-fifth intercostal space. Each blow produced a QRS complex on electrocardiography and a pulsatile deflection on the plethysmogram. An organized intrinsic rhythm returned after 3 impulses. The patient recovered uneventfully, and subsequent ECT sessions were preceded by prophylactic intravenous glycopyrrolate without recurrence. This case describes percussion pacing as an immediately deployable, equipment-free bridge within the cardiovascular rescue strategy for ECT services, with a low threshold to escalate to chest compressions and advanced cardiac life support.