Wearable cardioverter defibrillators are used by people who may be at higher risk for sudden cardiac arrest, including those with weakened heart function, awaiting cardiac transplant or with a condition that prevents or delays them from receiving an implanted defibrillator.
The device monitors heart rhythm, emits alarms if a serious arrhythmia occurs, delivers an electric shock to the heart if needed and alerts bystanders to help if the heart's electrical activity has stopped.
About 5,000 patients are using wearable defibrillators at any one time, usually for about 60 days, said Vincent N. Mosesso Jr., M.D., professor of emergency medicine at the University of Pittsburgh School of Medicine and principal investigator of the study.
"In these patients, the wearable defibrillator is a non-invasive 'insurance policy' against sudden arrest during their vulnerable period," he said.
Researchers gathered heart rhythm records and calls about shocks from a registry of 14,475 patients with wearable defibrillators listed from 2007 through 2009. Of those, 185 (about 1 percent) received an appropriate shock and 91.6 percent survived one or more episodes of ventricular fibrillation or ventricular tachycardia, the most common abnormal rhythms during cardiac arrest.
Wearable defibrillators delivered 223 inappropriate shocks to 213 people who weren't experiencing ventricular fibrillation or ventricular tachycardia. However, no one died as a result. Researchers attribute the inappropriate shocks to signal noise, rapid non-VT rhythms, and rhythm misinterpretation.
Only about 7 percent of people in the United States who have sudden cardiac arrest outside the hospital survive to hospital discharge, and only about 21 percent who have them in the hospital survive to discharge.
"This study confirms the effectiveness of very early defibrillation as therapy for sudden cardiac arrest in high-risk patients when delivered by a wearable defibrillator," Mosesso said. "These defibrillators provide patients the critical advantage of not having to wait for a bystander or emergency responder to recognize the cardiac arrest and use an automated external defibrillator or manual defibrillator — both of which can lead to delays in treatment and markedly worse survival rates."
Co-authors are: Jie Li, M.S.; Douglas Landsittel, Ph.D. and Leonard I. Ganz, M.D. Author disclosures are on the abstract.
ZOLL LifeCor of Pittsburgh, which makes the wearable defibrillator used in the study, funded the research.
Statements and conclusions of study authors that are presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The association makes no representation or warranty as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at www.heart.org/corporatefunding.
AHA News Media Office | EurekAlert!
UTSA study describes new minimally invasive device to treat cancer and other illnesses
02.12.2016 | University of Texas at San Antonio
Earlier Alzheimer's diagnosis may be possible with new imaging compound
02.11.2016 | Washington University School of Medicine
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy