April 3, 2009
Light and comfortable with life-saving power
UPMC Presbyterian pioneering development of wearable defibrillator for inpatients
The patient with a history of serious cardiac problems arrives on a Monday morning to undergo immediate insertion of a defibrillator. However, lab tests reveal a high level of a blood thinner, making it necessary to postpone surgery for several days.
“The issue now is how do we keep our patient safe until we can surgically insert the defibrillator that this individual so desperately needs,” explains Kathleen Zell, director, Cardiovascular Services, UPMC Presbyterian Shadyside.
The solution may be technology called LifeVEST®. Developed by ZOLL Lifecor, LifeVEST is a wearable defibrillator offering intervention for sudden cardiac arrest. Worn as a pack, rather than implanted in the body, the external device monitors the heart for abnormal rhythms with dermal-contact sensing electrodes. The vest alerts the wearer before delivering a biphasic electrical shock to restore normal rhythm.
Until recently, LifeVEST has been used only in the outpatient context, but a new design for inpatient use will be tried for the first time nationally at UPMC Presbyterian. Product engineers have met with directors of UPMC units where the device will be deployed for input on design considerations.
“For patient comfort, the inpatient model has to be lighter,” says Ms. Zell. “The technology also must be adapted to wear under hospital gowns. To do that, we’re reviewing a smaller version worn around the waist,” she adds.
In the inpatient setting, LifeVEST will provide added protection for patients who are waiting for implantation of internal defibrillators. For patients who have had in-chest defibrillators removed due to infection or who await surgery after discontinuing blood thinners, LifeVEST can be used for an interim period in the hospital until a defibrillator can be implanted.
The defibrillator vest is programmed by the physician to respond to a specific patient’s abnormal heart rhythm threshold. The patient’s EKG is recorded as a baseline. If arrhythmia is detected, the device sounds an alarm to alert the patient that a shock will be delivered. Since a shock is necessary only if the patient has lost consciousness, an alert patient can deactivate the device to prevent an unnecessary shock.
“Our goal is to do everything we can to keep our patients as safe as possible. This technology is another tool to help us attain that goal,” says Ms. Zell.