Vortices cause a dangerous stir in the heart

Cardiac ventricular fibrillation is a life-threatening disturbance in heart rhythm and function. It is thought to be triggered by abnormal patterns of electrical activity forming mechanical vortices within the heart muscle. This activity has never been visualized, only inferred from electrical vortices observed on the surface of the heart. Jan Christoph and colleagues combine high-resolution four-dimensional ultrasound imaging with optical mapping to visualize three-dimensional mechanical waves of contracting and dilating tissue propagating throughout the ventricular muscle during regular rhythm in perfused pig hearts. Upon the induction of ventricular fibrillation, electrical and mechanical scroll waves form within the ventricular wall. The findings confirm the prediction made 30 years ago that three-dimensional vortex-like waves inside the heart drive cardiac arrhythmias.