Calcium/calmodulin-dependent kinase II (CaMKII) is a multifunctional 
serine/threonine kinase expressed abundantly in the heart. CaMKII targets 
numerous proteins involved in excitation-contraction coupling and excitability, 
and its activation may simultaneously contribute to heart failure and cardiac 
arrhythmias. In this review, we summarize the modulatory effects of CaMKII on 
cardiac ion channel function and expression and illustrate potential 
implications in the onset of arrhythmias via a computer model.