ADRB2 and cardiac arrhythmia: Notably, βAR dysfunction is closely related to the development of HF and disease:, for example, cytoarchitectural changes that occur in HF affect the distribution and function of βARs.7 LTCCs have also been proposed as a key element in the development of HF,37–39 and we previously showed how their activity and distribution could lead to whole heart arrhythmias.2,40