March 3, 2017

Mutation raises heart block risk

A newly identified genetic risk factor for heart block after surgery may help guide the course of postoperative care.

Complete heart block (CHB), an interruption in the electrical signals that synchronize the heartbeat, occurs in about 3 percent of patients following congenital heart surgery. While most cases of CHB resolve within days, clinicians are limited in the ability to predict which patients will require implantation of a permanent pacemaker.

In a study published this month in the journal Heart Rhythm, Laura Murray, M.D., Prince Kannankeril, M.D., MSCI, and colleagues investigated risk factors for CHB in patients undergoing congenital heart surgery.

The authors determined that patients with a mutation in the gene GJA5, which encodes a protein essential for gap junction formation, were at greater risk for CHB. While this mutation did not predict the heart’s ability to recover from CHB, accelerated junctional rhythm and intermittent conduction were independently associated with one-to-one recovery of atrioventricular conduction.

These findings may prove useful to physicians in determining the course of postoperative care and whether to implant a pacemaker, the researchers concluded.

This research was supported by grants from the American Heart Association and National Institutes of Health (RR024975, TR000445, HL105334, HD084461).

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