Harish Manyam, MD, is on a mission to improve the lives of people with heart problems. His recent accomplishment of implanting Tennessee's first atrial leadless pacemaker is a step toward that, marking a significant advancement in cardiac care and promising safer and more effective treatment for patients.
The leadless pacemaker, in combination with a novel subcutaneous defibrillator, forms a groundbreaking system that addresses potentially dangerous problems associated with traditional pacemakers and defibrillators.
"This is a great leap forward for the field," said Dr. Manyam, interim chair of the Department of Medicine at the University of Tennessee Health Science Center's College of Medicine in Chattanooga and chief of Cardiology at Erlanger Health System. "We've always tried to do things in a way that can save patients' lives, but now we're thinking about ways to prevent complications for patients so they can live longer, healthier lives, which is really our mission at UT Health Science Center."
The new system was developed through an international study described in an article co-authored by Dr. Manyam and published in the New England Journal of Medicine.
One primary issue with traditional pacemakers and defibrillators is infection, which forces the removal of the leads, or the insulated wires that deliver electrical impulses to the heart.
"Traditionally, we implanted the devices under the skin near the left collarbone, and we would feed these wires from the device through the blood vessel and attach them to the heart muscle inside the heart," Dr. Manyam said. "What we saw with doing that for years is that people would develop bloodstream infections, with infection rates ranging up to 20%, as a result of an infection somewhere else in the body. When patients had those infections, bacteria would go into the bloodstream and grow onto the wires that we put in, and the only way to truly remove the bacteria from the body was to remove the wires themselves."
Another issue is that these flexible leads can break, also requiring removal from the body. Lead extraction is a risky procedure needing specialized tools, with increasing risk the longer the leads remain in the body and the more they grow into the heart tissue and the blood vessels, Dr. Manyam said. The goal of these new devices is to eliminate the need for the lead extraction procedure.
With the new system, the subcutaneous defibrillator is inserted in the left side of the body near the ribcage. The wire is tunneled under the skin and sits above the breastbone, so no component touches the blood pool. The leadless pacemaker, which is about the size of a AA battery, is inserted in the leg, led through the femoral vein, and attached to the inside of the heart. The two devices wirelessly communicate with each other to correct dangerous heart rhythms without having to shock the patient.
"The goal was to see if these two devices could work in communication with each other, and we found that they do," Dr. Manyam said. "When the leadless pacemaker sees a dangerous heart rhythm, it can appropriately respond to that event, it can perform antitachycardia pacing, and it can respond back to the defibrillator that it was doing that, so the defibrillator doesn't shock the patient. If that doesn't work, the pacemaker will let the defibrillator know, and the defibrillator itself will shock the patient."
This accomplishment comes after more than a decade of development. The study, led by Reinoud Knops, MD, PhD, from the Department of Cardiology at Amsterdam University Medical Center, involved dozens of researchers worldwide. Dr. Manyam joined during the development of the subcutaneous defibrillator and taught other doctors how to implant and use the device. Initially, doctors from across the country traveled to Chattanooga for training until Dr. Manyam and his team developed a virtual simulator to provide more accessible training to more doctors.
"We're really proud. This was a multi-site trial with funding from Boston Scientific and with lots of people involved in the trial to make sure it could work," Dr. Manyam said. "It's a testament to both UT Health Science Center and Erlanger working in concert to make sure that we can deliver really high-level research within the state. So, it's been one of the pinnacles of joy of my career to do this study and to be part of this."
The process and outcome of this study highlight why Dr. Manyam pursued a career in medicine: "to help people," he said. This motivation is also what led him to join Erlanger and the College of Medicine in Chattanooga. Dr. Manyam was particularly drawn to the educational aspect, along with the cutting-edge research and advanced cardiovascular care offered to the community.
"The advantage of doing research here is that you have the support of both Erlanger and the University of Tennessee Health Science Center to really progress with research and also progress with teaching our residents, medical students, and fellows," he said. "One of the things that make me excited about being a doctor every day is that I get to work with people who are learning, and I get to teach them different concepts that they don't know, and hopefully I instill in them a good work ethic and a core belief that they can take care of a bunch of other people."
