August 15, 2011

New Discovery of Genetic Factor Seen in Heartbeat Defect

(Ivanhoe Newswire) "“ Abnormalities in heartbeat synchronization, called heart arrhythmias, are a cause of death for 5.7 million Americans.  A scientist at the Gladstone Institutes has discovered how gene regulation can make hearts beat out of sync, offering new hope for the millions who suffer from a potentially fatal heart condition.

Gladstone Investigator Benoit G. Bruneau, PhD reveals the identity of the molecular regulator that uses electrical impulses to synchronize each heartbeat.

"This is important progress for a better understanding of heart arrhythmias, which when combined with heart failure can be fatal," Deepak Srivastava, MD, who directs all cardiovascular research at Gladstone, was quoted as saying. "This is the first published research about a genetic regulator that coordinates the timing of the electrical impulses that make the heart beat properly."

In many animals, including humans, electrical impulses must spread rapidly and in a coordinated fashion along a dedicated network of cardiac cells in order for the heart to pump blood efficiently to the rest of the body.

A genetic regulator, called Irx3, coordinates these impulses. When Dr. Bruneau and his team switched off the Irx3 gene in mice, the heart's pumping fell out of sync. The electrical impulses"”which normally follow a rapid path throughout the heart"”diffused slowly and had trouble reaching their intended destinations. The mice developed arrhythmias as the heart's chambers lost the capacity to beat in time.

"These findings have potential implications for the prevention and treatment of human heart disease, once we better understand Irx3's role in the human heart," Dr. Bruneau was quoted as saying. "An important avenue to explore could be whether humans with arrhythmias have mutations in the Irx3 gene.

"Now that we know the importance of Irx3," Dr. Bruneau added, "We need to dig deeper to see if it's possible to use drug therapy to target any of the electrical-impulse pathways that Irx3 regulates with drug therapy."

SOURCE: Proceedings of the National Academy of Sciences, published online August  2011