The latest interventional device in the cardiologist’s toolbox is tiny. But revolutionary. The Medtronic Micra™ Transcatheter Pacing System is leadless and the smallest single chamber pacemaker in the world. It was approved by the FDA in April 2016, and is currently awaiting a national coverage determination by the Centers for Medicare and Medicaid Services (CMS).
Implanted directly into the heart’s right ventricle, the device benefits selected patients with arrhythmias, offering a lessinvasive alternative to conventional pacemakers. Placed by catheter through the femoral vein, it shows great promise for some patients who need single chamber pacing.
MedStar Union Memorial Hospital and MedStar Washington Hospital Center will be two of the first sites in the region to use the new leadless pacemaker. “This is an expansion of current technology to help patients avoid some long-term vascular risks,” says Glenn Meininger, MD, an electrophysiologist at MedStar Union Memorial Hospital. “It is best suited for patients with limited vascular access, such as the elderly or patients with kidney disease or a cancer history.”
The device features a pacer and electrode in one unit, which is embedded in the right ventricle. The Micra is 93 percent smaller than conventional pacemakers. It is about the size of a large vitamin capsule and has a 12-year battery life. It adjusts to the patient’s heart rate automatically, sensing changes in the body related to activity level. It also enables patients to undergo MR imaging. Because there is no chest incision and no wires, the device results in faster recovery. “Having a wire connected to the device, there is a risk of infection or the wire can break,” Dr. Meininger explains. “This device limits that risk.”
In its current form, the Micra has limited use, Dr. Meininger cautions. Only 15 to 20 percent of patients would be eligible for this device as the current device only offers pacing in a single chamber of the heart, Dr. Meininger says. The real significance of this device is that it represents the wave of the future. “It highlights the transition to smaller, less invasive therapies that may allow rhythm management through micro technology,” Dr. Meininger concludes.