A new type of defibrillator implanted under the skin can detect dangerously abnormal heart rhythms and deliver shocks to restore a normal heartbeat without wires touching the heart, according to research in the American Heart Association journal, Circulation.
The subcutaneous implantable cardiac defibrillator (S-ICD®) includes a lead placed under the skin along the left side of the breast bone. Traditional implantable cardiac defibrillators (ICDs) include electrical conducting wires inserted into blood vessels that touch the heart.
ICDs can greatly reduce the risk of death in patients at high risk for sudden cardiac arrest.
Physicians insert the new device without X-ray guidance, and have reduced concerns about broken lead wires, vessel damage, vessel infection and scarring that make traditional device removal difficult.
“Defibrillation has repeatedly proven to be a great asset in prolonging the lives of cardiac patients, but there are still some risks to address,” said Martin C. Burke, D.O., senior author of the study and a professor of medicine and director of the Heart Rhythm Center at the University of Chicago. “This new system was developed over a dozen years to combine some of the best aspects of traditional implanted ICDs and external defibrillators.”
In the 33-site study, 314 of 330 patients (average age 52) evaluated had the S-ICD® implanted. During an average 11-month follow-up, 21 patients spontaneously developed 38 episodes of ventricular fibrillation or ventricular tachycardia. All were successfully restored to a normal heart rhythm. In addition, 41 patients (13.1 percent) received shocks that were inappropriate because they weren’t preceded by a dangerous heart rhythm.
The study surpassed goals set by the U.S. Food and Drug Administration for evaluating the safety and effectiveness of the new device:
Ninety-nine percent of the S-ICD® patients remained free of complications 180 days following implantation, compared with a 79 percent goal.
When tested by a purposely-induced abnormal rhythm following implantation, the S-ICD® was 100 percent effective at consistently detecting and reversing ventricular fibrillation. The FDA goal is 88 percent.
The S-ICD® has been available in Europe and New Zealand since 2009 and received FDA approval in the United States in 2012.
Participants in the study, along with new patients, will be followed to assess the performance of the new device over time.
Patients with certain types of pacemakers, and those with symptoms related to a slow heartbeat, should not use an S-ICD®. Data from the registries will be used to determine the range of patients who might be helped by the device, including those on dialysis and those with birth defects involving the heart.
“The S-ICD® is not a replacement for other defibrillators,” Burke said. “For some patients it will be ideal, for others inappropriate, and the vast proportion in the middle will be able to select the type of system they want,” Burke said.
A comparison between a traditional ICD and the S-ICD® is underway.
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
The above story is based on materials provided by American Heart Association.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
R. Weiss, B. P. Knight, M. R. Gold, A. R. Leon, J. M. Herre, M. Hood, M. Rashtian, M. Kremers, I. Crozier, K. L. Lee, W. Smith, M. C. Burke. Safety and Efficacy of a Totally Subcutaneous Implantable-Cardioverter Defibrillator. Circulation, 2013; 128 (9): 944 DOI: 10.1161/CIRCULATIONAHA.113.003042
Note: If no author is given, the source is cited instead.
Number of stories in archives: 141,736
Interested in ad-free access? If you’d like to read ScienceDaily without ads, let us know!
more breaking science news
Follow ScienceDaily on Facebook, Twitter, and Google:
Recommend ScienceDaily on Facebook, Twitter, and Google +1:
Other social bookmarking and sharing tools:
… from NewsDaily.com
more science news
In Other News …
more top news
Science Video News
Listen To Your Heart
Scientists have developed a new tool that may eliminate unnecessary visits to a specialist by allowing doctors to examine and assess heart murmurs.. … > full story
Strange Science News
… from ScienceDaily
Get the latest science news with our free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:
… we want to hear from you!
Tell us what you think of ScienceDaily — we welcome both positive and negative comments. Have any problems using the site? Questions?