Exercise-induced polymorphic ventricular tachycardia in adults without structural heart disease

Area of Science:

• Cardiology
• Electrophysiology
• Genetics

Background:

• Catecholaminergic polymorphic ventricular tachycardia (CPVT) typically manifests in childhood with exercise-induced ventricular arrhythmias (VAs) and often a positive family history.
• Atypical presentations, such as adult onset without a family history, require careful consideration for diagnosis and management.

Purpose of the Study:

• To describe a cohort of adult patients with exercise-induced ventricular arrhythmias (VAs) who presented atypically (adult onset, negative family history).
• To evaluate the efficacy of beta-blocker or calcium channel blocker therapy in managing these patients.

Main Methods:

• Retrospective analysis of exercise treadmill electrocardiographic data from patients referred for exercise-induced VA.
• Inclusion criteria: adult onset of exercise-induced bidirectional, pleomorphic, or polymorphic ventricular tachycardia, negative family history, and no structural heart disease.
• Correlation of VA complexity with heart rate before and after pharmacologic therapy (beta-blocker or calcium channel blocker).

Main Results:

• Eight adult patients with exercise-induced VAs and negative family history were identified.
• Pharmacologic therapy (primarily beta-blockers) effectively controlled symptoms and reduced VA complexity.
• Drug therapy increased the heart rate threshold for VA induction and decreased the duration and complexity of premature ventricular complexes.

Conclusions:

• Adult-onset CPVT can occur without a family history and is often responsive to beta-blocker or calcium channel blocker therapy.
• Pharmacologic management can significantly decrease ectopic complexity and increase the heart rate threshold for inducing VAs.
• These findings suggest a favorable prognosis for adult-onset CPVT managed with appropriate pharmacotherapy.