Definition & Overview
A pacemaker is a small, battery-operated device that is surgically implanted into the chest and sends electrical pulses to regulate the heartbeat. It is recommended for patients who have heart problems that cause their heart to beat either too fast or too slow resulting in various symptoms such as fainting spells, lightheadedness, shortness of breath, and tiredness.
Who should undergo and expected results
A pacemaker implant is helpful for those who are suffering from or experiencing:
- Bradycardia - an abnormally slow heart rate usually caused by a damaged sinoatrial node
- Supraventricular tachycardia - an abnormally fast heart rate also typically caused by a damaged sinoatrial node
- Heart block - when false electrical signals in the heart cause irregular heartbeat
- Cardiac arrest - when electrical problems inside the heart cause it to stop beating, endangering the person's life
A pacemaker is implanted using a simple and straightforward procedure. It is designed to send electrical pulses to the heart to ensure that it beats at a steady rate, which is called the discharge rate. This rate can be adjusted depending on the person's needs or condition. The device is implanted just once and contains a battery that can last for six to ten years, depending on the type of pacemaker used. More modern devices tend to use more energy and thus last for a shorter period. A pacemaker works with the help of a pulse generator and a computer circuit that converts the energy from the battery into electrical pulses that effectively stimulate heart contractions on demand; this means that if the device detects disruptions or senses that the heart is not beating normally, it starts to send electrical signals, but stops when the heart starts beating normally again.
Pacemakers are also expected to keep pace with the body's activity level, thanks to their special sensor that recognizes whether the body is more active and thus require a faster discharge rate.
How the procedure works
Pacemakers are implanted by a cardiologist or medical professionals who specialize in treating heart conditions and have received special training in dealing with pacemakers.
Prior to a pacemaker implant surgery, patients undergo an assessment test to make sure they are fit for the surgery. This assessment test, which usually involves blood tests and X-rays, helps determine the best form of implant surgery to be performed, which could either be transvenous implantation or epicardial implantation.
A pacemaker implant surgery begins with the administration of local anesthetic, which leaves the patient awake but he or she will not feel anything during the procedure. Once the anesthesia takes effect, the surgery begins.
Transvenous implantation – This procedure is done by making a 2-inch long incision on the left side of the chest near the collarbone. Since the pacemaker is placed just under the skin, it does not require a highly invasive procedure. Once the pacemaker is placed, it is connected to the heart using a lead (or wire) that is guided through a blood vessel. In some cases, more than one lead is used; this depends on the type of pacemaker used, i.e. whether it is a single chamber, dual chamber, or biventricular pacemaker. Regardless of the type of device used, the procedure takes just an hour but patients are typically required to stay the night at the hospital for observation. They are normally well enough to go home the next day and can soon resume their normal activities.
Epicardial implantation – This procedure works by making an incision in the abdomen just below the chest and attaching the pacing lead to the heart's outer surface called the epicardium. Since this is an open surgery, it requires general anesthesia. This is performed only if the patient is also scheduled for an open-heart surgery. This type of surgery takes longer and requires a longer recovery period.
Regardless of which method is used, the pacemaker is first tested right after placement. This is a necessary step to ensure that the device is working properly. During the testing process, patients can expect to feel their heart beat faster. It is important for patients to tell the surgical or medical team immediately if they experience any unusual symptoms during this testing stage so adjustments can be made immediately.
Possible risks and complications
Pacemaker implantation, especially those done through transvenous means, have a very low risk of complications.
To avoid possible post-surgery complications, patients are advised to avoid strenuous activities for the first four to six weeks following the implantation. Once fully recovered, the pacemaker should not limit their activities and patients should be able to handle most activities, even sports.
The possible complications with a pacemaker implant includes:
- Patient discomfort - Pacemakers tend to cause some discomfort at first because they can be easily felt, especially when lying down, but patients soon get used to them.
- Allergic reactions – Patients may have some allergic reactions to the anesthesia used during the procedure. Thus, it is important for patients to tell their doctors regarding any allergies they may have prior to the surgery.
- Pacemaker malfunction – The major risk is when the device itself malfunctions. When this occurs, another surgery will be required to replace the device.
To avoid complications and to shorten recovery time, patients should eat a healthy diet and stop smoking.
- Swerdlow CD, Hayes DL, Zipes DP. Pacemakers and implantable cardioverter-defibrillators. In: Mann DL, Zipes DP, Libby P, et al, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 36.