New Revelations about the Long-QT Syndrome

Sudden death, a devastating event for any family, strikes more than 300,000 Americans each year. Cardiac arrhythmias, particularly ventricular arrhythmias, are thought to account for about 11 percent of all sudden deaths. In some cases there appears to be a familial propensity for sudden death. One inherited condition, the Romano–Ward long-QT syndrome, is an autosomal dominant disorder of cardiac repolarization that results in ventricular arrhythmias and sudden death. The long-QT syndrome has been thought to arise from either an abnormality of ion-channel regulation (the myocellular hypothesis) or altered activity of the autonomic nervous system, but definitive proof of either hypothesis . . .