Cherian*, an octogenarian, was a post by-pass surgery patient, who also underwent a stent implantation. He later developed a stent re-block which was opened again with a new technology called drug coated balloon (DCB) angioplasty.
However, very recently he developed an episode of unconsciousness. To completely understand his condition, he was put under a 24-hour evaluation with ECG monitoring. “During this period, he developed another episode of unconsciousness and the ECG showed that the heart had stopped completely for over six seconds,” said Dr Binoy John, the head of interventional cardiology at Venkataeshwara Hospital, Nandanam, Chennai. This clearly pointed out to the heart’s pacemaker, called the SA node, had failed and the patient needed an artificial pacemaker implantation to prevent another cardiac arrest, Dr John added. The SA node is what generates heart beats, normally at rates of 60-100 beats per minute.
Considering the advanced age and health history, the patient was implanted with a leadless pacemaker and was also discharged within a day. The procedure on Cherian was performed by Dr Binoy John and team which included Dr Madhu Sankar, head of CTVS, and Dr Thillai Vallal, senior cardiologist, at Venkataeswara Hospital. As this new type of pacemaker eliminates the need for leads (wires) that connect to the heart, it offers advantages like reduced risk of infection and complications associated with traditional pacemakers.
Leadless pacemakers are a great advancement in pacemaker technology and a blessing for many patients. This pacemaker does not have wires or large battery and doesn’t need a surgical pocket for its implantation. It is approximately 3cm in length, shaped like a bullet and is miniscule compared to a conventional pacemaker which has the size of a matchbox. The battery and the electrical components are all located in this bullet-shaped capsule. It is implanted directly into the heart through a vein in the leg using a catheter. As there is no surgical pocket, the patient can be discharged the very next day. Other advantages include easily removability and longer battery life (16-17 years) compared to conventional pacemaker.
Conventional pacemakers which have been used over the past decades, in millions of patients consists of a battery or pulse-generator and one or two long wires or leads which are placed inside the chambers of the heart through a vein under the collar bone. The opposite ends of the leads are then connected to the battery which is then inserted inside a surgical pocket made by making a cut or incision under the skin below the collarbone. After pacemaker insertion, the skin and tissues are stitched with sutures. The battery generates the electrical impulses which are conducted through the leads to the heart muscle causing the heart to beat adequately and pump effectively.
Though a relatively safe procedure and tolerated well by majority of the people, conventional pacemakers can be associated with risks like bleeding, infection and pus formation in the pocket, in which case prolonged hospitalisation is needed to manage removal of the battery and leads. Longer healing periods and such complications may be higher in the elderly, frail, and diabetic patients. Elderly patients usually have more comorbidities, longer healing time, and may be on blood thinner medications which can increase the risk of bleeding. It’s in these patients that the new technology of leadless pacemakers, have come as a much safer option.
However, leadless pacemakers have some limitations like cost and limited clinical scenarios. As it costs three times more (around `15 lakh), many patients may not be able to afford it currently. With just around a total of 1,300 leadless pacemaker implantations performed in India since its introduction in 2018, further developments in the leadless pacemaker technology are ongoing, and it would be a game changer in pacing technology for all age groups in the future.