Dr. Jaime Gonzalez, a Harvard-educated cardiac electrophysiologist at Memorial, is the first physician in Colorado to implant an MR-compatible defibrillator in a patient. Gonzalez has placed the device in two patients since the FDA approved it Sept. 14.
The defibrillator detects abnormal heart rhythms and then delivers a life-saving shock to return the heart to normal rhythm. In the past five years, ICDs have saved approximately 70,000 lives, studies show.
Anticipated to become the standard of care, the MRI-safe ICD has hardware and software that allows it to be safe in an MRI. Previously, patients with a defibrillator have not been able to have an MRI because of potential interactions that may result in malfunction of the device.
“We are at the forefront of everything that is coming out,’’ Gonzalez said of Memorial’s cardiac program. “Our cardiac team at Memorial is at the cutting edge of the field.’’
MRIs are used to detect multiple conditions, be it cancer, stroke or bone and back pain. Medtronic, the manufacturer of the new defibrillator, estimates that within four years, more than one-third of people who have an implantable defibrillator are likely to need an MRI for another medical condition.
“MRI is a very robust modality with a plethora of applications and the use of the technology continues to expand with each passing year,’’ said Jarad Muasau, director of radiology at Memorial. “It’s become the gold-standard for many orthopedic, neurological, musculoskeletal, and cardiac exams.
“When a patient has a non-compatible device implanted in them, MRI is no longer an option, and we’re forced to instead use modalities that aren’t optimal in finding what the patient’s doctor might be looking for. These MRI-compatible devices do their jobs while ensuring patients still have access to the cutting-edge imaging offered in MRI,’’ Muasau said.
During the one-hour surgical procedure to implant the MRI-compatible defibrillator, a patient is placed under conscious sedation while a four-to-five- centimeter incision is made in the chest. The device, about half the size of an iPhone, sits in the chest wall, just under the skin.
Using a needle, the surgeon finds the vein that leads from the arm into the heart and then threads a lead that screws it into the heart. Defibrillators are placed in those who are at risk of dying suddenly from ventricular arrhythmia, or in a case where a patient has already had an event and the device is placed to prevent another incident.
When the defibrillator begins to detect abnormal heartbeats, it delivers small electrical stimuli to pace the heart into a normal rhythm. If that doesn’t work, it delivers an electrical shock.
“People describe it very differently, and the descriptions are always very interesting. People have told me: ‘It’s like Mike Tyson coming out and punching them in the chest; a mule kicking in the chest.’ or like being on a golf course and getting hit by a golf ball in the chest.’’’
The defibrillator lasts 8-10 years, and the battery is checked every three months.
“We do it remotely. We send patients home with a wireless device that plugs into the wall. Every three months, we schedule a home interrogation visit, and it sends us a report that provides data about lead integrity, the battery and more,’’ Gonzalez said.
The doctor said that the new device provides patients with peace of mind that they are receiving the very latest offered in cardiac care.