Calcium is an important mediator in cardiac excitation and disorders in cardiac 
Ca(2+) homeostasis have great influence on the cardiac action potential. 
Therefore dysfunction in regulatory proteins that are involved in Ca(2+) 
handling can lead to the occurrence of severe arrhythmia. Although mutations in 
Ca(2+) regulating proteins are quite rare, they can offer general insights into 
arrhythmogenesis. Here, we briefly review some important aspects of 
arrhythmia-associated mutations in Ca(2+) regulating proteins with special 
emphasis to its associated pathophysiology.