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Updated: May 10, 2026

Dual-Dye Optical Mapping of Hearts from RyR2R2474S Knock-In Mice of Catecholaminergic Polymorphic Ventricular Tachycardia
09:36

Dual-Dye Optical Mapping of Hearts from RyR2R2474S Knock-In Mice of Catecholaminergic Polymorphic Ventricular Tachycardia

Published on: December 22, 2023

Decreased RyR2 refractoriness determines myocardial synchronization of aberrant Ca2+ release in a genetic model of

Lucia Brunello1, Jessica L Slabaugh, Przemyslaw B Radwanski

  • 1D. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH 43210, USA.

Proceedings of the National Academy of Sciences of the United States of America
|June 5, 2013
PubMed

Insights

Synchronized calcium release in heart cells causes dangerous arrhythmias like catecholaminergic polymorphic ventricular tachycardia. This study reveals how these calcium events become synchronized, leading to triggered heart activity.

Area of Science:

  • Cardiovascular Physiology
  • Molecular Cardiology
  • Cardiac Electrophysiology

Background:

  • Dysregulated intracellular calcium (Ca2+) signaling is a key factor in cardiac arrhythmias, particularly catecholaminergic polymorphic ventricular tachycardia.
  • Spontaneous diastolic calcium release (DCR) can trigger arrhythmogenic events, but the mechanisms synchronizing DCR among myocytes are not fully understood.

Purpose of the Study:

  • To investigate the synchronization mechanisms of DCR that lead to untimely action potentials and diastolic contractions (DCs) in a mouse model of catecholaminergic polymorphic ventricular tachycardia.
  • To elucidate how aberrant DCR events become synchronized in the intact myocardium.

Main Methods:

  • Utilized single ryanodine receptor channel recording.
  • Employed optical imaging for Ca2+ and membrane potential analysis.
  • Performed contractile force measurements in ventricular myocytes and intact cardiac muscles.

Main Results:

  • Demonstrated temporally and spatially uniform DCR in myocytes and myocardial tissue from a cardiac calsequestrin mutation mouse model.
  • Showed that synchronized DCR events induce triggered electrical activity and synchronous DCs.
  • Established that abbreviated ryanodine receptor channel refractoriness and preceding synchronous Ca2+ release/reuptake dynamics drive DCR synchronization.

Conclusions:

  • Aberrant DCR events can synchronize within the intact myocardium.
  • This synchronization leads to triggered activity and diastolic contractions in cardiac rhythm disorders.
  • Understanding these mechanisms is crucial for developing treatments for catecholaminergic polymorphic ventricular tachycardia and related arrhythmias.
Keywords:
RyR2 deactivationcalcium-induced calcium releaseluminal calciumsarcoplasmic reticulum

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