Patients with implanted heart devices know getting diagnostic imaging can be tricky and even dangerous. Researchers have found a way to reprogram the devices, allowing patients to safely receive certain MRI scans.
Those with pacemakers or implanted defibrillators used to control abnormal heart rhythms and prevent sudden cardiac death are usually asked to skip MRI imaging scans.
The strong magnets in MRIs could cause the devices to overheat or malfunction.
Dipan Shah, MD, medical director of cardiac MRI at the Methodist DeBakey Heart & Vascular Center at The Methodist Hospital in Houston, noted that MRIs can cause a pacemaker to become confused and think that a patient’s heart is beating properly when it may not be.
He said that reprogramming implanted devices to get around this problem is critical so patients can receive these scans.
Because MRI scans could be dangerous, some patients with pacemakers or defibrillators have been unable to get imaging scans to detect medical conditions that could be missed otherwise. MRIs show clearer images of organs and structures, and can detect tumors, blood vessel disease and infections.
Doctors at the Methodist DeBakey Heart & Vascular Center found a method for reprogramming the devices through a specific protocol that allows patients to safely receive an MRI for brain or orthopedic injury.
Dr. Shah said that after the device is reprogrammed prior to the MRI, doctors closely monitor a patient’s heart rate, oxygen levels and blood pressure while the scan is taking place. The device is programmed back to normal levels following the scan.
”MRI is only performed if the benefits of the test outweigh the potential risks to the patient,” Dr. Shah said. “That being said, it’s comforting to know that MRI is now an option for them if they need it to potentially save their life.”
The Heart Center is part of a multi-center study that is currently investigating the long-term effects of MRI on patients with implanted pacemakers and defibrillators.
In the United States, over 850,000 people are hospitalized from an arrythmia, a general term for a large group of conditions that results from abnormal electrical activity in the heart. Also known as cardiac dysrhythmias, they can cause the heart to beat too fast, too slow, or in an irregular pattern.
The conditions can range from benign to life-threatening, and in some cases can cause sudden death. Common ‘palpitations’, such as premature ventricular contractions, may be simply uncomfortable and not need treatment, but others like atrial fibrillation need treatment because they increase the risk of stroke. In many cases, arrythmias will need treatment because they can lower blood pressure to the point that a patient can faint.