Wire-free at heart

September 6, 2019 0 By FM

Conventional pacemakers are external devices that are placed in a pocket in the chest area and stimulate the heart muscles through a connecting lead or wire. Pacemaker implantation has become a routine procedure performed on thousands of patients every year in India alone. While the technology has dramatically progressed over the past six decades since the first pacemaker was implanted, the procedure is still cumbersome and requires 2-3 hours to place the device in the chest after a surgical incision and connect it to the right side of the heart through wires. In addition, the patient needs to be hospitalised for 3-4 days. Moreover, the patient’s mobility is restricted post-surgery. Surgical complications such as infections are also common and suitable antibiotic precautions are necessary. In the event of an infection that reaches the device, a device replacement may also be required. Another concern with implanting conventional pacemakers is the controversy surrounding the use of MRI after implantation. Since MRI is a widely used diagnostic tool that is likely to be required for patients with implantable pacemakers, MRI-safe devices are now available, albeit, at an added cost.

Over the years, pacemakers have become thinner and smaller; and algorithms and software programmes have evolved to simulate the heart as close to normal as possible. However, the most recent advancement in pacemaker technology has led to the pacemaker becoming leadless or wireless. Approved by the FDA in the United States in 2016, the world’s smallest pacemaker, the leadless Micra transcatheter pacing system has been available in the Indian market since early 2017. With technical expertise and perhaps even cost being a deterrent, this technology is currently available only at limited specialty hospitals across the country. In fact, to ensure patient safety and outcomes, it is mandatory that the procedure is supervised by a trained proctor for at least the first 20 implants before a cardiologist can independently perform the procedure in any patient.

The newly available leadless device is the size of a large vitamin capsule, about 93% smaller than conventional pacemakers. This small size makes it convenient and simple to introduce it into the heart via the femoral vein. making the procedure less invasive. Without the requirement of a chest incision, the surgical procedure is only about 30 mins, leaves no scars or bumps, and also reduces the chances of infections that are often seen post conventional pacemaker implantation. Being leadless, it also eliminates potential complications arising due to dislodgment of the wires. It is MRI safe and has a long battery life of 10-12 years. Like conventional pacemakers, regular follow-ups are required where an external programming machine is used to monitor the functioning and battery life of the pacemaker through radiofrequencies.

Dr Vashisth Das, Cardiologist, recently brought Chinmaya Narayana Super-specialty Centre, Bangalore, to the small list of hospitals that offer leadless pacemaker technology. He successfully implanted the leadless pacemaker in the heart of an 83-year-old woman, giving her a renewed lease of life.

Mrs. Nanda (name changed) came to the CCU of Chinmaya Narayana Super-specialty Centre, Bangalore, in a state of collapse. After being revived, Dr Das and his medical team informed Mrs Nanda of the need for pacemaker implantation to improve her quality of life. Dr Das explained the possible pros and cons regarding both conventional and leadless pacemakers to her and her family. Mrs Nanda was apprehensive of the conventional pacemaker implantation procedure due to its associated morbidity; however, she readily agreed for the leadless option. With Mrs Nanda’s long list of comorbidities, including congenital heart disease, ischemic heart disease, chronic kidney disease, her age and frail constitution, a short and simple procedure with a short hospital stay won the case for implanting the leadless device.

Dr Das is excited at the prospects that the leadless pacemaker brings to the future of cardiac treatment: “The delivery and implantation of these pacemakers have evolved to such an extent that no surgery is required, except for a venous puncture which does not leave any scars. Mrs Nanda, while anxious prior to the procedure, recovered soon, was discharged the very next day after the procedure, and was very happy with the outcome.”