RyR2 inhibitors can be classified into Class I agents like flecainide, which are primarily antiarrhythmic, and Class II agents like dantrolene, which are preferable in heart failure.
Provides a mechanistic classification of RyR2 inhibitors into Class I (antiarrhythmic) and Class II (preferable in heart failure) to guide therapy in arrhythmogenic heart diseases.
Ryanodine receptor type 2 (RyR2) is the principal intracellular calcium release channel in the cardiac sarcoplasmic reticulum (SR). Pathological RyR2 hyperactivity generates arrhythmia risk in genetic and structural heart diseases. RYR2 gain-of-function mutations cause catecholaminergic polymorphic ventricular tachycardia. In structural heart diseases (i.e., heart failure), posttranslation modifications render RyR2 channels leaky, resulting in pathologic calcium release during diastole, contributing to arrhythmogenesis and contractile dysfunction. Hence, RyR2 represents a therapeutic target in arrhythmogenic heart diseases. We provide an overview of the structure and function of RyR2, and then review US Food and Drug Administration–approved and investigational RyR2 inhibitors. A therapeutic classification of RyR2 inhibitors is proposed based on their mechanism of action. Class I RyR2 inhibitors (e.g., flecainide) do not change SR calcium content and are primarily antiarrhythmic. Class II RyR2 inhibitors (e.g., dantrolene) increase SR calcium content, making them less effective as antiarrhythmics but preferable in conditions with reduced SR calcium content such as heart failure.
Q. et al. (2024) conducted a review in Arrhythmogenic heart diseases. RyR2 inhibitors was evaluated. RyR2 inhibitors can be classified into Class I agents like flecainide, which are primarily antiarrhythmic, and Class II agents like dantrolene, which are preferable in heart failure.