CaMKII and a failing strategy for growth in heart.

Patients with systolic left ventricular dysfunction die progressively from congestive heart failure or die suddenly from cardiac arrhythmias. Myocardial hypertrophy is an early event in most forms of heart failure, but the majority of patients with myocardial hypertrophy do not develop heart failure. Developing improved therapies for targeting the cell signaling pathways that enable this deadly transition from early myocardial insult to heart failure and sudden death is a key goal for improving public health. In this issue of the JCI, Ling and colleagues provide new evidence that activation of the multifunctional Ca(2+)/calmodulin-dependent kinase IIdelta is a decisive step on the path to heart failure in mice (see the related article beginning on page 1230).