Ontario hospital implants powerful new defibrillator

St. Michael's HospitalDec 22 2010

Minimally invasive surgeries mean smaller scars, quicker recovery

St. Michael's Hospital today became the first in Ontario to implant a small but powerful new defibrillator into a patient's chest.

The defibrillator - about the size of a Zippo lighter - is the smallest available in terms of surface area and can deliver the highest level of energy, 40 joules.

The narrow shape of the device allowed Dr. Iqwal Mangat to make a smaller incision in the patient's chest, which should mean a faster recovery and smaller scar. The "minimally invasive" procedure is performed on an outpatient basis, with most patients going home the same day. The small size also means less patient discomfort and less obvious signs of the device under the patient's skin.

The high-energy capability of this device is especially important for patients who have an enlarged weak heart, advanced heart failure or have previously required a high amount of energy to shock their heart back to a normal rhythm.. This device is also coupled with an additional lead on the left side of the heart that allows the heart to "resynchronize," potentially allowing patients to feel more energy and less short of breath.

"The more energy there is in a device to shock a patient, the more likely it is their life will be saved by that device," said Dr. Mangat, director of the hospital's arrhythmia services. "Most people don't need a lot of energy, but sometimes they do."

The new Unify CRT-D defibrillator is made by St. Jude Medical, Inc., based in St. Paul, MN.

St. Michael's implants about 290 defibrillators and 230 pacemakers a year.

What is the difference between a pacemaker and an implanted defibrillator?

A pacemaker is about one-quarter the size of a defibrillator. It monitors your heart rhythm - which slows with age and certain medications - and sends electrical pulses to your heart if it is beating too slow or you miss a heartbeat.

A defibrillator is a small, battery-powered device that treats a dangerous fast heart rhythm by delivering a jolt of electricity to the heart. They are typically implanted in patients who have or are at risk for developing ventricular tachycardia or ventricular fibrillation, two types of very fast and life-threatening heart rhythms that originate from the ventricles, the lower chambers of the heart.