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Pacemaker

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Pacemakers are devices that are implanted into the body, just below the collarbone, to take over the job of the heart’s own electrical system and prevent slow heart rates. Although they weigh only an ounce and are the size of a large wristwatch face, a pacemaker contains a computer with memory and electrical circuits, a powerful battery (generator), and special wires called “leads.” The generator creates electrical impulses that are carried by the leads to the heart muscle, signaling it to pump.

Sudden Cardiac Arrest (SCA) occurs when the heart stops beating, abruptly and without warning. If this happens, blood stops flowing to the brain and other vital organs. In addition, if the heartbeat is not restored with an electrical shock immediately, death follows within minutes. SCA accounts for more than 350,000 deaths in the U.S. each year.

SCA accounts for more than 350,000 deaths in the U.S. each year and is one of the leading causes of death in the United States each year. In fact, SCA claims one life every 90 seconds, taking more lives each year than breast cancer, lung cancer or AIDS. Unfortunately, 95 percent of people who experience SCA die as a result, mainly because treatment within minutes is not accessible.

Defibrillation, or shock, can be the only way to stop certain heart arrhythmias, or irregular heartbeats, before they kill. If the heart beats too quickly, the chambers, or ventricles, will not have enough time to fill with blood and pump blood to the rest of the body, which can cause death. For people at high risk for the deadliest forms of arrhythmias – called ventricular tachycardia and ventricu­lar fibrillation – an internal “shocking” device may be the best protection against sudden cardiac arrest (SCA).

A normal heartbeat is controlled by a smooth, constant flow of electricity through the heart. A short-circuit anywhere along this electrical pathway can disrupt the normal flow of signals, causing an arrhythmia (an irregular heartbeat). Cardiac ablation is a procedure used to destroy these short-circuits and restore normal rhythm, or to block damaged electrical pathways from sending faulty signals to the rest of the heart.

Though it may feel like the heart has skipped a beat, a premature heartbeat occurs when the heart's regular rhythm is interrupted by an early or even extra heartbeat. If the beat arises from locations in the atria (upper chambers) it is called premature atrial contraction (PAC). If it arises from the ventricles (lower chambers), it is called premature ventricular complexes (PVC). In most cases, neither is considered serious.