**Abstract**

The rhythmic contraction of the heart relies on tightly regulated calcium (Ca) release from the sarcoplasmic reticulum (SR) Ca release channel, Ryanodine receptor (RyR2). Genetic mutations in components of the calcium release unit such as RyR2, cardiac calsequestrin and other proteins have been shown to cause a genetic arrhythmic syndrome known as catecholaminergic polymorphic ventricular tachycardia (CPVT). This book chapter will focus on the following: (1) to describing CPVT as a stress-induced cardiac arrhythmia syndrome and its genetic causes. (2) Discussing the regulation of SR Ca release, and how dysregulation of Ca release contributes to arrhythmogenesis. (3) Discussing molecular mechanisms of CPVT with a focus on impaired Ca signaling refractoriness as a unifying mechanism underlying different genetic forms of CPVT. (4) Discussing pharmacological approaches as CPVT treatments as well as other potential future therapies. Since dysregulated SR Ca release has been implicated in multiple cardiac disorders including heart failure and metabolic heart diseases, knowledge obtained from CPVT studies will also shed light on the development of therapeutic approaches for these devastating cardiac dysfunctions as a whole.

**Keywords:** EC coupling, Ca-dependent arrhythmias, RyR2, Ca signaling, sudden cardiac death, DCR
