CaV1.2 sparklets in heart and vascular smooth muscle

► CaV1.2 sparklets are local elevations in intracellular Ca2 + visualized with optics. ► CaV1.2 sparklet activity is heterogeneous in cardiac and smooth muscle cells. ► CaV1.2 sparklets are locally controlled by a signaling hub coordinated by AKAP150. ► Cluster of CaV1.2 channels can open and close in unison (i.e., coupled gating). ► Coupled gating amplifies Ca2 + influx in cardiac and smooth muscle.