Stay CALM when the heart skips a beat

A new CALM mutation causes lethal arrhythmia in humans. Using cardiomyocytes — or heart muscle cells — from human iPS cell and recombinant calmodulin proteins, the group studied catecholaminergic polymorphic ventricular tachycardia — or CPVT, a rare and life-threatening genetic condition. The team was able to reproduce severe arrhythmia in patient-derived iPS cell models of exercise-induced CPVT with calmodulin mutations.