What is a pacemaker?

By Vision Reporter

THE normal human heart has a natural pacemaking mechanism which sets the rate and rhythm at which the heart beats, ensuring that the heart contracts and pumps blood out to the rest of the body. <br>

THE normal human heart has a natural pacemaking mechanism which sets the rate and rhythm at which the heart beats, ensuring that the heart contracts and pumps blood out to the rest of the body.

The heart’s natural pacemaker is called the sinoatrial (SA) node, a small mass of specialised cells in the top of the heart’s right atrium; it generates the electrical impulses that cause your heart to beat.

There are situations though, where the natural pacemaker may be defective, causing the heart to beat too fast, too slow or irregular. The heart’s electrical pathways also may be blocked.

Abnormal heart rate can cause weakness, fatigue, lightheadedness, dizziness, loss of consciousness, or even death. According to Dr Paul D’arbela, a consultant cardiologist with the heart centre in Nakasero, conditions that affect the efficiency of the heart’s pace-making mechanism include damage to the SA node during a heart attack, or trauma during heart surgery.

A person may also be born with the deficiency. One of the most threatening conditions is a complete heart block, where the heart beats approximately 15 times per minute instead of the normal 72 times. In this case, an artificial pacemaker has to be implanted.

It is a small battery-operated device that helps regulate the frequency of the heart rate and coordinates contraction of the heart muscle so that the heart beats efficiently. Some pacemakers are temporary (external) and others are permanent (internal).

The permanent ones are surgically implanted in the tissue overlying the muscle under the patient’s collarbone.
Once the incision heals, which could take two-three weeks, the patient returns to a normal life. One can live with this device for up to 10 years before the battery starts to go low.

Thereafter, the cardiologist replaces it with a new one. D’arbela adds that the possibility of the heart’s natural pacemaker to degenerate increases with age and eating of fatty foods.

He, however, says regular exercise helps to keep trouble a way from the heart, as well as a healthy diet.

Complications of an artificial pacemaker
Home appliances like ovens and microwaves allegedly interfere with the functioning of the device.
According to D’arbela, this is not true. He says only devices that generate powerful magnetic fields can inhibit the function of pacemakers and under some circumstances be dangerous to the pacemaker and patient. Such devices include security scanners, heavy duty industrial motors and magnetic resonance imaging scanners.
Cellular phones, if held in close proximity to the pacemaker can affect the function of the device, but if the phone is kept more than six inches away from the pacemaker, there should be no problem.

What is a pacemaker?