Several genetic variants that predispose individuals to sudden cardiac death have been identified in two studies published online this week in Nature Genetics. The discovery may help to explain and possibly treat irregular heart palpitations that often underlie severe cardiac dysfunction.

Sudden cardiac death is associated with the amount of time between heartbeats, where abnormally prolonged or shortened durations increase the risk for irregular heartbeats. This causes a disruption in the electrical and chemical signalling necessary for a healthy heart.

Two large independent association studies carried out by the QTSCD and QTGEN Consortia have identified ten new regions of the genome that contain common variants significantly associated with heartbeat intervals. These associations were found near genes previously known to modulate the electrical activity of the heart, such as sodium and potassium ion channels, or near genes that are plausible but unsuspected candidates involved in heart cell growth and development, blood pressure regulation, and calcium release.

The identification of the precise mechanism underlying the effects of these common variants on abnormal heartbeat intervals will be critical to improving the design of therapeutics used to maintain and enhance cardiovascular function.