For the first time, patients implanted with a new type of pacemaker at Elkhart General Hospital can now safely undergo magnetic resonance imaging (MRI) to accurately visualize soft tissue for such common indications as neurologic (stroke), cancer and orthopedics (including bone disease).
The Revo MRI SureScan pacemaker from Medtronic Inc., which was approved by the Food and Drug Administration in February, is constructed of nonmetallic material and contains wires that are heavily insulated to prevent magnetic interference.
The Hospital’s first Revo implant was performed in March and as of July an additional five patients have received the pacemaker.
“Although this pacemaker is slightly larger and the wires a little thicker than a conventional pacemaker, patients do not feel any difference,” says Gurudutt B. Kulkarni, M.D., a Board Certified Cardiologist at Midwest Cardiovascular Specialists, who has performed all surgeries to date. “Because the wires are thicker, it is slightly more difficult to rotate the wires within the heart muscle. It takes additional turns to properly affix the wires. But that is a minor technical difference.”
The procedure under local anesthesia takes about one hour, the same as a standard pacemaker, for which the patient remains in the Hospital one night. “In general, the Revo pacemaker is for people who have a primary slow rhythm with a relatively normal heart,” Dr. Kulkarni notes. “We don’t expect these patients to require other types of devices in the future, such as an implantable defibrillator.”
Dr. Kulkarni says most patients are delighted when he notifies them that he is implanting them with an MRI-compatible pacemaker. In fact, the initial patient from March was exceedingly glad that she was going to be the first.
The powerful magnetic field of an MRI can interfere with a typical pacemaker’s function, according to Dr. Kulkarni, and cause the pacemaker to pace fast and inappropriately. “But the greatest concern with an intense magnetic field is that it can generate heat at the tip of the leads (wires) of the pacemaker and sometimes even destroy the leads, thus increasing the amount of current needed to pace the heart.” Internal tissue scarring can also occur. “This increased scarring will make the typical pacemaker not function properly,” Dr. Kulkarni states. Hence, adjustments may be necessary, sometimes in an emergency situation.
“Overall, 50 to 75 percent of our pacemaker patients have a medical need for an MRI over their subsequent lifetime,” says Rebecca Jellison, RN, MSN, MBA, HCM, Manager of Cardiac Diagnostics, the Cardiac Cath Lab, the Electrophysiology (EP) Lab and Cardiovascular Recovery at Elkhart General Hospital. “Individuals over the age of 65 are twice as likely to need an MRI than younger populations. However, alternative imaging devices are unable to see as much detail as an MRI.”
Jellison believes the new Revo pacemaker has revolutionized pacemaker implants for our aging population. By the end of the year, at least two other competing manufacturers will introduce similar products.
Additionally, Dr. Kulkarni is hopeful that an MRI-safe pacemaker will lead the way for two other commonly implanted cardiac devices to become MRI-compatible as well: defibrillators and combination biventricular/defibrillators. “Having all the hardware safe for use with MRI will certainly be great progress,” he says.
For More Information
For more information on the Elkhart General Hospital Center for Cardiac Care or the Revo MRI SureScan pacemaker, call 574-523-3303.