Early-Morning Type Ventricular Fibrillation With J Wave

Area of Science:

• Cardiology
• Electrophysiology

Background:

• A 67-year-old male experienced cardiopulmonary arrest (CPA), successfully resuscitated with bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use.
• Electrocardiogram revealed J waves in inferior leads, prompting implantable cardioverter defibrillator (ICD) implantation.

Observation:

• Post-ICD implantation, the patient experienced recurrent ventricular fibrillation (VF) episodes twice monthly, predominantly between 1:00 and 6:00 AM.
• Ventricular premature contractions (VPCs) consistently preceded VF events, suggesting a pattern of autonomic nervous system influence.

Findings:

• Administration of long-acting disopyramide (150 mg/day at bedtime) was initiated to target the early morning VF occurrences.
• Disopyramide, a muscarinic receptor antagonist, demonstrated efficacy in preventing further VF episodes.

Implications:

• Long-acting disopyramide can be an effective therapeutic option for managing recurrent, early-morning ventricular fibrillation.
• Targeting autonomic dysfunction with pharmacological agents like disopyramide may reduce ICD shocks and improve patient outcomes.