Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare genetic heart condition characterized by an abnormal heart rhythm (arrhythmia) that can lead to sudden cardiac arrest, particularly during physical activity or emotional stress. The condition is caused by mutations in genes responsible for regulating calcium levels in the heart muscle cells, leading to irregular electrical signals and potentially life-threatening ventricular tachycardia.