Safe MRI in Patients With Cardiac Devices: It Takes a Team

Suraj Kapa, MD: Greetings, my name is Suraj Kapa, and I'm a cardiologist at Mayo Clinic. During today's Round Table Review, we will be discussing [magnetic resonance imaging] MRI in patients with devices. I am joined by my colleagues, Dr Paul Friedman, vice chair of cardiovascular diseases; Dr Robert Watson, chair of neuroradiology; and registered nurses Connie Dalzell and Nancy Acker, who specialize in pacing. Welcome.

All: Thank you.

Dr Kapa: As a general question, why are you worried about MRI in patients with devices?

Paul A. Friedman, MD: Historically, patients were scanned, at times, without awareness that they had implantable devices. Those devices weren't designed to tolerate MRI scans. The scans can generate currents in the devices, and those currents can induce arrhythmias. They can cause cautery to the heart muscle, and there were cases of fatalities because dangerous arrhythmias were induced in patients.

It's important to note that that was in the 1980s.

Since then, devices have undergone significant evolution. Since at least the early '90s, with new pass-through filters and other technologies—although they vary by the manufacturer—have been much more resistant to external electromagnetic interference.

Defining MRI-Safe, MRI-Unsafe, MRI-Conditional

Robert Watson, MD: That's correct.