Dear Doctor: My mom is 93, and her doctor says she needs a pacemaker to control a heart arrhythmia. How does a pacemaker work? Is the operation dangerous for someone her age?
Dear Reader: A pacemaker is a small medical device that uses electrical pulses to keep the heart beating at a steady rhythm. It may be needed to stimulate a faster heart rate in cases where the patient’s heart has begun to beat too slowly, or to correct potentially dangerous rhythm problems.
The device consists of two parts -- a battery-operated pulse generator, which contains a small computer chip, and between one and three fine wires, known as leads, which are tipped with electrodes. The generator, which is about the size of a matchbox or smaller, is surgically implanted beneath the skin of the chest, often near the collarbone. The leads are threaded through a vein that leads to the heart, and the electrodes are placed within those chambers of the heart that require outside stimulus. The specifics of the number of leads in a person’s pacemaker, as well as electrode placement, depend on the specific condition the pacemaker is treating.
Once the device has been implanted, the electrodes, which are sensors, read the electrical signals from the heart. They then transmit this data to the computer chip within the generator. Whenever an abnormal heart rate, or arrhythmia, is detected, the computer in the pacemaker instructs the generator to send corrective electrical impulses to the heart muscle. Adjustments can be made with a specialized computer called a programmer, which communicates with the pacemaker.
Pacemaker technology has benefited greatly from the tech revolution, and it continues to evolve. The earliest devices, which date back to the 1960s, were about the size of a hockey puck. Several years ago, a tiny pacemaker that’s smaller than a AAA battery won FDA approval. This device, which has no leads because it is placed directly in the chamber of the heart, is limited to certain patients with specific types of heart pacing needs.
The procedure to implant a pacemaker is performed in a cardiac catheterization lab, usually under small amounts of sedation in combination with local anesthesia. It’s considered to be a minimally invasive surgery, and it typically takes from one to two hours. Potential risks of the surgery include bleeding, infection, swelling or bruising, damage to the blood vessel used to guide the leads, or an adverse reaction to anesthesia used during the surgery. Patients either go home to recover the same day, or they spend one night in the hospital for observation. In the month following pacemaker surgery, patients must be careful to avoid vigorous exercise and heavy lifting.
About 400,000 pacemakers are implanted in the United States each year, half of them in people over age 75. And while surgery carries risks for people of any age, the complication rates of pacemaker implantation are low, including among patients who are in their 80s and 90s. Your mother’s own medical history is an important factor as well. We recommend that you speak with her cardiologist about the risks of the surgery versus the risks of going without it.
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