It delivers a life-saving shock to the heart without ever actually touching it. Doctors at St. Paul’s Hospital, in collaboration with Cardiac Services BC and a group of physicians from around the province, have taken a step towards revolutionizing the care of people with cardiac arrhythmias in British Columbia by implanting the first ever subcutaneous implantable cardioverter defibrillator (S-ICD) in BC.
“One of the biggest challenges we face with implantable defibrillators is the invasiveness of the procedure,” says Dr. Jamil Bashir, cardiac surgeon and director of the laser lead extraction program at St. Paul’s. “This new device is a paradigm shift that allows us to shock the heart without having to place a wire in the blood vessels. Because the heart and blood vessels are untouched, the potential for blood vessel injury is eliminated, the potential for system infection is reduced and the patient’s vein access is preserved for the future.”
The primary purpose of the device is to monitor the patient’s heartbeat and deliver a potentially life-saving shock that disrupts a fast heart rhythm and resets the heart. Conventional ICDs, which involve a lead being placed in the veins of the upper chest, are connected directly to the heart. This feature is required for many patients who receive an ICD, and remains the standard of care in BC. The S-ICD, on the other hand, uses electrodes placed just under the skin (in the extrathoracic space) and not in the heart, leaving the heart and veins untouched. The device delivers a shock across the chest wall with the heart positioned in between.
Mike McLellan, a sporting goods wholesaler from Squamish, was the first patient in BC to receive a S-ICD. The 44-year old father of three has not only fully recovered from surgery, but completed a grueling, four-day, 650 kilometer bike ride just a few months after having the device implanted.
“The S-ICD will only fire if it detects that I need it,” says McLellan. “I kind of look at it like a lifejacket. It’s always listening to my heart and it can differentiate between exercise and a medical issue.”
The S-ICD provides defibrillation therapy for the treatment of life-threatening ventricular tachyarrhythmias. It is a promising new device because the absence of an intracardiac lead means the need for complicated surgeries to extract failed leads is avoided. This complication occurs in about 1 in 200 patients every year.
“To be the age that I am, relatively young for heart issues, it allows you to not be at risk for that invasive lead removal or lead extraction with traditional ICDs,” says McLellan.
Nearly 1,000 conventional defibrillators are implanted in patients around the province per year for protection against potentially fatal arrhythmias. In addition to the defibrillation feature of an ICD, many patients also require longer term pacing. At this time, the S-ICD is currently unable to provide this therapy but may eventually be suitable for patients with other types of heart disease.
Since the first procedure, St. Paul’s Hospital, in collaboration with Cardiac Services BC and a provincial physician review panel, has implanted 18 more S-ICDs into patients. The implant team has been led by Dr. Bashir, cardiac surgeon and director of laser lead extraction program at St. Paul’s.