A pacemaker is a small device that sends electrical impulses to the heart muscle to maintain the proper number and rhythm of the heartbeat; In addition, it may be used to treat syncope, congestive heart failure, and rarely, hypertrophic cardiomyopathy. This device is implanted under the skin of the chest during a short surgery. A healthy heart has its own pacemaker that regulates the heart rate. But some hearts do not have a regular rhythm, a problem known as arrhythmia. In most cases, a pacemaker can correct this problem.