Shabanu,   Thanks for your question which is commonly asked by concerned families.  A pacemaker is a small device (about the size of an Ipod Nanno) which is usually used to maintain normal heart rhythms.  There are several types with different functions, but basically it is a small generator (battery) that senses the patient's heart beat.  If too slow, the pacemaker will deliver an electrical stimulus to the heart which then initiates a heart beat.  If the patient's heart beat is adequate, the unit will be in a stand-by mode while sensing the rhythm/rate.    The procedure is considered minor, mostly because there is no general anesthesia.  It is done with local anesthesia at the surgical site (left or right upper chest), and the unit is placed just under the skin.  The electrical leads are advanced through a vein into the heart.  This is all done with Xray guidance to be sure placement is correct.  There is little recovery time, and patients can go about their routines the next day. Fortunately, the complication rate is extremely low.    So overall, the benefit of this procedure almost always outweighs the risk.  Hope all works out well.   Martin Cane, M.D.