New Defibrillator Works Without Wires Touching Heart
Device is more durable, making it an alternative for younger patients, researchers say
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The S-ICD has been used in Europe and New Zealand since 2009 and was approved by the U.S. Food and Drug Administration in 2012, but long-term study is still required, the researchers said.
One expert said there's a place for the new defibrillator.
"The subcutaneous defibrillator adds additional value for patients with indications for an implantable defibrillator who are poor candidates for standard systems," said Dr. Leslie Saxon, chief of the division of cardiovascular medicine at the University of Southern California and author of an accompanying journal editorial.
Since the device is not a pacemaker, however, it doesn't provide many options other devices do. "[Doctors should] think carefully about defibrillator selection and individualize patient care," Saxon said.
Another expert said more clinical experience is needed to determine which patients will benefit most from its use.
"It is estimated that 200,000 to 400,000 people die suddenly every year in the United States, and the majority of these deaths are the result of the heart rhythm abnormalities ventricular tachycardia or ventricular fibrillation," said Dr. Gregg Fonarow, a professor of cardiology at the University of California, Los Angeles.
Although this study found the new device exceeded FDA-specified goals in terms of efficacy and safety, "additional studies with longer-term follow-up are needed to better define the effectiveness, safety and ideal patient population for this new device," Fonarow added.
For the study, 314 patients using the device were evaluated over an average of six months. During that time, 21 patients had 38 episodes of ventricular fibrillation or ventricular tachycardia -- abnormal rhythms that precede cardiac arrest. The average age of the patients was 52.
In each case, the device restored the heart to a normal rhythm, the researchers reported. Forty-one patients, however, received shocks when the heart wasn't in a dangerous rhythm.
Ninety-nine percent of the patients had no complications from the device in the 180 days following implantation. In testing, the device recognized and reversed abnormal, life-threatening rhythms 100 percent of the time.