At Last, a More Precise Pacemaker
When cardiologist Kevin Donahue considered his elderly patient’s weakening heart, he worried over the possible downside of installing a traditional pacemaker. The patient had suffered a series of heart attacks and now courted heart failure. A pacemaker was certainly in order, but Donahue knew all too well how its constant drumbeat could put undue stress on a cardiac muscle that only needed an occasional boost.
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| Cardiologist Kevin Donahue says the new dual chamber pacemaker answers the need for more carefully timed pulses of electricity. |
Then Donahue, who specializes in electrophysiology, considered a new idea he’d seen at November’s gathering of the American Heart Association: A manufacturer there had unveiled a device that employed “managed ventricular pacing,” a novel technology that allowed cardiologists to tailor electrical pacing to a patient’s actual needs. “This one watches more than it paces,” Donahue says, explaining that the device “only paces the bottom chamber of the heart when it really has to. It detects a pause, and then kicks in.”
Clinical studies have shown that unnecessary pacing in the right ventricle—the “bottom chamber”—can increase the risk of heart failure and atrial fibrillation. Traditional pacemakers don’t have the ability to adjust pacing mode when the ventricles change from independent beating to needing pacing. This means the right ventricle is often paced unnecessarily. The new pacemaker can be programmed to deliver pacing pulses to the right ventricle less than 2 percent of the time. The device, called the EnRhythm pacemaker, also provides an advanced diagnostics capability that can assist physicians in detecting additional heart rhythm irregularities, especially in the atrium. “It will also tell us the percentage of heartbeats that are paced,” says Donahue.
Another feature of the device is an exclusive advancement of anti-tachycadia pacing that can painlessly terminate fast heart rhythms in the atria, the top chambers.
Altogether, this device is indicated for patients who suffer from either bradycardia—often caused by a sinus node dysfunction—or for patients with atrial arrhythmias.
The new device debuted for clinical trials last year in seven centers in the Netherlands, Sweden, Germany, Austria and Canada, and was approved for commercial use in the United States by the FDA on April 29. Within days, Donahue described the technology to his new patient, advising that it presented the optimal course for averting heart failure. To the man on the brink of a deadly condition, it all made perfect sense.
And so, on May 11, Donahue implanted the new pacemaker. He says the man returned home the next day and is doing well.
“We were not the first hospital in the nation to use this device,” Donahue says, “but we were the first in the Mid-Atlantic region.”
Donahue reports that Hopkins last year implanted 150 pacemakers along with 208 defibrillators that also provide a pacing function.
