Arrhythmia characterization and long-term outcomes in catecholaminergic polymorphic ventricular tachycardia

Heart Rhythm. 2011 Jun;8(6):864-71. doi: 10.1016/j.hrthm.2011.01.048. Epub 2011 Feb 9.

Abstract

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is characterized by adrenergically induced ventricular tachycardia (VT) associated with syncope and sudden death.

Objective: This study sought to characterize arrhythmias associated with CPVT with respect to provocation by exercise and drugs, electrocardiographic characteristics, and association with long-term outcomes; and to explore the relation between age and clinical presentation.

Methods: Seventy patients from 16 families were evaluated with exercise and selective adrenaline challenge, and screened for RyR2 mutations. CPVT was diagnosed in probands with symptoms and stress- or adrenaline-provoked VT, or in asymptomatic relatives with provoked VT or RyR2 mutations. Patients were followed up for recurrent syncope, VT, and sudden death.

Results: Twenty-seven patients including 16 probands were identified (median age 35 years, 67% female). Presentation was cardiac arrest in 33% and syncope in 56%, and 11% were asymptomatic. Polymorphic or bidirectional VT was provoked with exercise in 63% and adrenaline in 82%. The initiating beat of VT was late-coupled and wide (coupling interval 418 ± 42 ms; QRSd 131 ± 17 ms), and QRS morphology suggested an outflow tract origin in 59%. During follow-up of 6.2 ± 5.7 years, 2 patients died despite an implantable cardioverter-defibrillator (ICD), 4 patients received ICD therapy for VT, and 5 patients had inappropriate therapy for supraventricular tachycardia. Patients presenting with late-onset CPVT (age > 21; n = 10) were often female (80%) and less likely to have RyR2 (Ryanodine receptor type 2) mutations (33%), and fatal events were not observed during follow-up (4.1 ± 3.6 years).

Conclusion: Ventricular arrhythmia in CPVT is often initiated from the outflow tract region. Despite β-blocker therapy and selective ICD implantation, breakthrough arrhythmias occur and may be associated with adverse outcomes.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adrenergic beta-Antagonists / therapeutic use
  • Adult
  • Aged
  • Catecholamines / metabolism*
  • Child
  • Child, Preschool
  • DNA / genetics*
  • Death, Sudden, Cardiac / epidemiology
  • Death, Sudden, Cardiac / etiology*
  • Death, Sudden, Cardiac / prevention & control
  • Defibrillators, Implantable
  • Electrocardiography
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Mutation*
  • Ontario / epidemiology
  • Risk Factors
  • Ryanodine Receptor Calcium Release Channel / genetics*
  • Survival Rate / trends
  • Syncope / epidemiology
  • Syncope / etiology*
  • Syncope / prevention & control
  • Tachycardia, Ventricular / complications
  • Tachycardia, Ventricular / genetics*
  • Tachycardia, Ventricular / metabolism
  • Time Factors
  • Young Adult

Substances

  • Adrenergic beta-Antagonists
  • Catecholamines
  • Ryanodine Receptor Calcium Release Channel
  • DNA

Supplementary concepts

  • Polymorphic catecholergic ventricular tachycardia