Pacemakers Reduce NMS Fainting

Patients with neurally mediated synope aided by pacemakers

(RxWiki News) Patients with a heart arrhythmia aren't the only ones who could benefit from a pacemaker. Those with neurally mediated synope (NMS; a condition where the brain does not regulate heart rate and blood pressure, prompting fainting spells) could also benefit.

Italian researchers have determined that patients with NMS could significantly reduce fainting episodes through implantation of a dual-chamber pacemaker.

"Ask your cardiologist about appropriate NMS therapy."

Dr. Michele Brignole, head of cardiology at the Arrhythmologic Centre, Ospedali Tigullio in Italy and the study’s lead investigator, said that researchers found that about 33 percent of pacemaker patients could benefit from pacing therapy within the next two years because it is effective in reducing fainting spells among a highly selected population.

Though NMS is generally not fatal, many patients have no warning before fainting, and it can result in repeated falls or difficulty driving or operating machinery.

During the 51-center study, investigators enrolled 511 patients over the age of 40 who had suffered at least three NMS episodes over the past two years. Unlike in previous studies, participants were not affected by blood pressure fluctuations. Many participants in previous research also had severe hypotension, which caused their blood pressure to drop and subsequent dizziness as they stood or moved to a new position.

During the Third International Study on Syncope of Uncertain Etiology (ISSUE-3) trial, physicians used a device similar to a mini-EKG machine to determine participants' cause of fainting. Investigators found that 77 patients had a spontaneous asystolic syncope, meaning they had sudden episodes that caused them to lose consciousness. Clinicians implanted a pacemaker randomly set to the "off" or "on" position in the 77 patients.

Researchers discovered that 57 percent of patients who were implanted with a pacemaker set to "off" had a fainting incident within two years, while only 25 percent of those with a pacemaker turned on fainted.

Investigators suggested pacemakers could be useful for NMS patients whose disorder is unpredictable and can impede their daily life. Most often, that would be older patients since younger NMS sufferers usually have a more benign form of the condition and respond better to less drastic therapies. Though it may aid patients, Dr. Brignole said cardiac pacing only should be used as a last choice for patients severely affected by NMS.

The research, funded by Medtronic Bakken Research Center, was presented Monday, March 26, 2012 at the American College of Cardiology’s annual scientific sessions.

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Review Date: 
March 26, 2012