Slowing the Racing Heart

Scientists have discovered how we put the brakes on a racing heartbeat. An enzyme acts on the heart's pacemaker to slow the rapid beating of the heart's "fight-or-flight" reaction to adrenaline. A single cell in the upper right chamber is responsible for setting the pace of the beating heart, triggering its neighbor cells to beat. Current treatment of arrhythmia requires destruction of tissue surrounding a chaotic pacemaker, followed by insertion of a mechanical pacemaker that can regulate the heartbeat. "Understanding the molecular regulation of the heart's pacemaker opens the possibility of less drastic treatment options, including drug interventions."