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Chronotropic incompetence as a risk predictor in children and young adults with catecholaminergic polymorphic

Sonia Franciosi1, Thomas M Roston1,2,3, Frances K G Perry1

  • 1Division of Cardiology, Department of Pediatrics, Children's Heart Centre, BC Children's Hospital, University of British Columbia, Vancouver, Canada.

Journal of Cardiovascular Electrophysiology
|June 25, 2019
PubMed

Insights

Chronotropic incompetence (CI) during exercise stress tests is linked to worse outcomes in catecholaminergic polymorphic ventricular tachycardia (CPVT) patients. However, antiarrhythmic therapy may mitigate this risk, suggesting CI

Area of Science:

  • Cardiology
  • Electrophysiology
  • Genetics

Background:

  • Catecholaminergic polymorphic ventricular tachycardia (CPVT) poses a significant risk of life-threatening arrhythmias.
  • Current risk stratification tools for CPVT are limited, highlighting the need for improved prognostic markers.
  • The exercise stress test (EST) is crucial for diagnosing and assessing the prognosis of CPVT.

Purpose of the Study:

  • To investigate the association between heart rate (HR) and blood pressure (BP) response during EST and the risk of arrhythmias in CPVT patients.
  • To determine if chronotropic incompetence (CI) during EST is a predictor of ventricular arrhythmia burden.
  • To assess the impact of antiarrhythmic therapy on the prognostic value of CI and BP response in CPVT.

Main Methods:

  • A cohort of 20 CPVT patients underwent EST.
  • Chronotropic incompetence (CI) was defined by HR reserve values <80% (off therapy) and ≤62% (on therapy).
  • Ventricular arrhythmia score (VAS), syncope, cardiac arrest, and BP response during EST were analyzed in relation to CI, both off and on maximal antiarrhythmic therapy.

Main Results:

  • CI in untreated CPVT patients was associated with a higher VAS during EST (P=.046) and a greater frequency of syncope/cardiac arrest (P=.008).
  • Patients with CI exhibited lower peak systolic BP during EST (P=.041), a finding that persisted on maximal therapy (P=.033).
  • Antiarrhythmic therapy appeared to attenuate the increased arrhythmia risk associated with CI, as VAS was similar between CI and non-CI groups on therapy (P=.50).

Conclusions:

  • Chronotropic incompetence during EST is a significant prognostic indicator for ventricular arrhythmias and adverse events in untreated CPVT patients.
  • Antiarrhythmic therapy may modify the risk associated with CI, suggesting its potential as a therapeutic target.
  • Further research is warranted to confirm these findings in larger cohorts and elucidate the underlying mechanisms linking CI to arrhythmia susceptibility in CPVT.
Abstract

Keywords:
CPVTchronotropic incompetenceexercise stress testheart rateventricular arrhythmia

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