In a previous article we explored slow heart rates and the disease processes that bring them about. This week we will consider the role of pacemakers in improving the lives of people who suffer from inappropriately slow heart rates.

It is important to realise that for patients who have slow heart rates resulting in inadequate blood flow to the tissues of the body, treatment options are limited. For a patient who is hospitalised, there are some medications that can be infused to temporarily increase the heart rate. For an outpatient, a pacemaker is the only option that we have to appropriately treat a sustained slow heart rate that is causing symptoms.

In our society this is an important issue as pacemakers used in our country are not produced here and must be purchased using scare foreign exchange. There have been cases of patients with a need for pacemakers who have been unable to afford them.

What is a pacemaker?

Physically a pacemaker system consists of a generator and leads. The generator is a metal box about one and a half times the size of a domino. This box contains the pacemaker battery and a microprocessor that controls pacemaker function. The leads are wires that run from the battery to the muscle of the heart. These wires allow the pacemaker device to sense the electrical activity of the heart and also to transmit electrical pulses from the battery to heart muscle ie, to “pace” the heart.

It is interesting to note the advances in pacemaker technology that have taken place of the past 70 years. The first pacemakers were extremely large and cumbersome with the battery being the size of a shopping cart. This required early patients to push the battery ahead of them. Over the years the size of the batteries has gradually decreased, and the life of the battery has increased so that currently a battery can be expected to last up to 10 years and can be implanted under the skin.

How is a pacemaker placed?

It is often surprising to patients when they learn that a pacemaker can be placed under local anaesthesia and that routine pacemaker placement takes less than one hour. The implanting physician usually makes an incision of around two inches under the clavicle. The leads are introduced through the incision into the large vein that runs next to the clavicle. This vein leads directly to the right side of the heart allowing the physician to place the leads in the muscle of the heart with little difficulty. The generator is then placed, connected to the leads and the incision closed.

In experienced hands the complication rate of the procedure is less than one per cent. Although the procedure sounds relatively simple it does require specialised equipment and trained physicians. As noted above, the pacemaker and leads must be obtained from overseas. A surgical suite or sterile procedure room with the ability to use X-rays to visualise the heart is also needed, as the leads must be guided through the body using X-ray imaging. In many cases pacemaker placement requires only a short stay in the hospital with many patients being discharged the following day.

Life with a pacemaker

It is important to realise that patients with pacemaker can have essentially normal lives. It is one of the more gratifying procedures that we can perform as many patients can be disabled with symptoms of slow heart rates. They can present with severe symptoms including recurrently passing out, resulting in injury, particularly among the elderly. Less severe symptoms include the inability to exercise as the heart rate will not increase to get adequate blood flow to working muscles.

Most patients who appropriately receive a pacemaker notice an immediate improvement in quality of life. Having a pacemaker does, however, mean that the patient will be under the intermittent supervision of a cardiologist for the remainder of their lives. Generally, after pacemaker placement, for the first few weeks the patient will be followed in the clinic to make sure that the device is functioning appropriately and that the incision is healing well without infection. Occasionally adjustments will need to be made in terms of device programming. After this initial period patients are often seen in pacemaker clinic once or twice per year.

The purpose of these intermittent visits is primarily to monitor the performance of the pacemaker system. Each company that produces pacemakers will make a pacemaker interrogation device. This can be held over the pacemaker allowing communication with the device and assessment of pacemaker function. Most pacemakers on the market currently have reliability that exceeds 99 per cent.

Rarely issues such as movement of the leads can occur, resulting in the need for repositioning. The longer the pacemaker is in place the greater the concern about death of the battery. At each pacemaker evaluation the pacemaker will provide an estimate of the life of the battery remaining. When the battery life falls to a few months, the pacemaker battery is usually replaced in a minor surgical procedure under local anaesthesia.

Currently a patient with a pacemaker may estimate the need and expense for a battery change every 10 years. In the United States and Europe many pacemakers are sold that have telemetry functions. This allows the pacemaker to “talk” to a receiving device that can be placed in the patient’s bedroom. These receiving devices are often connected to the home phone allowing the pacemaker to communicate with the pacemaker company each night decreasing the need for that patient come to a pacemaker clinic. An important advantage of having a pacemaker is the fact that the heart rate and rhythm are monitored continuously, and pacemakers can serve as warning systems for the occurrence of abnormal fast heart rhythms.

Patient concerns and cautions

A common concern among patients with pacemakers is possible interference from household electrical equipment, particularly microwaves. Current generations of pacemakers are sufficiently shielded that this is not a concern. Some industrial equipment or motors generate electrical fields which can be an issue affecting pacemaker function. People working in these industries need to consult with their physicians and often times the pacemaker company. This problem can also be noted in some surgical procedures and pacemaker function may sometimes need to be adjusted around the time of the operation.

A common issue that arises is screening at airports or going through metal screeners. It is possible for these devices to affect pacemaker function and we recommend that patients should travel with their pacemaker cards and request manual screening. A significant issue that has been resolved concerns pacemakers and magnetic resonance imaging (MRI). Having a pacemaker formerly was a contraindication to getting an MRI. Nowadays most pacemakers produced are MRI safe, however many patients still have pacemakers implanted years ago which cannot be safely placed in an MRI machine. Therefore, if there is a need for an MRI, pacemaker patients should consult with their cardiologist.

Pacemakers offer life-changing treatment for patients and are increasingly being used in Jamaica. Problems of access and affordability, however, do remain an issue for too many of our patients.

— Dr Paul Edwards, MD, FACC and Dr Ernest Madu, MD, FACC are consultant cardiologists at Heart Institute of the Caribbean (HIC) and HIC Heart Hospital. HIC is the regional centre of excellence for cardiovascular care in the English-speaking Caribbean and has pioneered a transformation in the way cardiovascular care is delivered in the region.

Dr Madu is a main TED speaker whose TED talk has been translated into 19 languages, seen, and shared by more than 500,000 viewers. He has received the Distinguished Cardiologist Award, the highest award from the American College of Cardiology, and has been named among the 100 most influential people in health care and among the 30 most influential in public health. Dr Madu is also a recipient of the Global Health Champion Award from the University of Pennsylvania. He was past CEO of HIC and is currently the chairman of IHS Holdings Ltd, an asset management company with interests in the USA, Africaand the Caribbean.

Correspondence to info@caribbeanheart.com or call 876-906-2107