A first in Quebec: MUHC heart specialists implant new “smart” defibrillator


McGill University Health Centre (MUHC) heart specialists are the first in Quebec (and the second in North America) to implant a fully automatic biventricular cardiac resynchronization therapy defibrillator. While continuously working to “pace” the patient’s heart, this “smart” technology allows the defibrillator to adjust itself automatically if it senses any change in the patient’s condition.

On July 17, 2008 this innovative device was implanted into a patient suffering from severe heart failure and at increased risk of going into cardiac arrest. The procedure was performed in the biplane heart catheterization lab by Dr. Vidal Essebag, MUHC Director of Cardiac Electrophysiology. The patient, a 78 year-old male, was able to return home the next day. His energy and endurance have improved steadily since his cardiac resynchronization procedure.

Cardiac resynchronization therapy defibrillators improve heart function and can also rescue patients from a cardiac arrest. “This newest defibrillator introduces a completely automatic self-diagnostic technology,” explains Dr Essebag, who also practices at Sacré-Cœur Hospital. When the device is implanted, three wires are run from the defibrillator, each into one of three chambers of the heart. These wires function to “pace” the heart using a programmed amount of energy, depending on the patient’s needs. The device checks how much energy is required to make each chamber beat, and adjusts the amount of energy delivered accordingly. This new feature complements the device’s ability to monitor heart failure fluid status and transmit data to clinicians from home using wireless technology.

This “smart” technology, developed by Medtronics, offers patients an extra level of security. “There is a minimum amount of energy (voltage) required to make a heart chamber beat, and this can vary over time depending on the wire and the heart in question,” says Dr. Essebag. “If the programmed amount of energy is below this minimum, the heart chamber won’t beat in response to the delivered energy. To be safe, we program the energy higher than necessary, but this increases battery drain. The new device verifies the amount of energy required on a daily basis and adjusts the programmed amount. As a result, a lower voltage can be programmed more safely. Ultimately this reduces battery drain.” In addition, the device is able to record the performance of the patient’s heart over time. This helps physicians manage their patients more effectively.

The implant of this new device is the latest in a series of ground-breaking procedures performed by members of the MUHC Cardiovascular Sciences Program. On February 8, 2007 MUHC cardiologists performed the first percutaneous pulmonary valve replacement. That December, they performed the first percutaneous aortic valve replacement. More recently, on February 19, 2008, they were responsible for the first Impella 5.0 implant. “This is another milestone for us, and a step forward in the treatment of patients with congestive heart failure," says Dr. Essebag.

The McGill University Health Centre
The McGill University Health Centre (MUHC) is a comprehensive academic health institution with an international reputation for excellence in clinical programs, research and teaching. Its partner hospitals are the Montreal Children's Hospital, the Montreal General Hospital, the Royal Victoria Hospital, the Montreal Neurological Hospital, the Montreal Chest Institute and the Lachine Hospital. The goal of the MUHC is to provide patient care based on the most advanced knowledge in the health care field and to contribute to the development of new knowledge.

Contact Information

Rebecca Burns
MUHC Public Relations and Communications
rebecca.burns [at] muhc.mcgill.ca
Office Phone: 
(514) 843 1560