HOW DOES A PACING SYSTEM WORK?
A pacing system is made up of a pacemaker and a pacing lead. A pacemaker has electronic circuitry and a battery. A pacing lead completes the electrical pathway between the pacemaker and the heart. A pacing system does two major things: Pacing and Setting. Pacing means that a pacemaker sends an electrical impulse to your heart through a pacing lead. This pacing pulse starts a heartbeat. The pacemaker paces the heart when the hearts own rhythm is interrupted, irregular or too slow. A pacemaker will also sense the hearts natural electrical activity. When a pacemaker determines that a heart rhythm is too slow, it emits a pacing pulse to the heart. When the pacemaker senses a natural heartbeat, it will not deliver a pacing pulse.
Pacemakers relieve many symptoms for most patients. However, Pacemakers are not cures they are just a treatment underlying heart rhythm disorders. Pacemakers will not prevent or stop heart disease or prevent heart attacks.)

WHAT IS A PACEMAKER?
A Pacemaker is made up of a battery and electronic circuitry sealed in a metal case. A connector block, into which the leads are inserted, is affixed to the metal case.
The pacemakers battery supplies the power of the pacemaker. The batter is a very small, lithium battery. This battery typically lasts between 5 and 10 years depending on the amount of time it is being used.
The circuitry is a miniature computer inside the pacemaker, which transforms the energy from the batter into tiny electrical pulses. It is the tiny electrical pulses that stimulate the heart to beat. The circuitry controls the timing and intensity of the electrical impulses delivered to the heart.
The case is where the battery and circuitry are sealed in a metal case.
The connector block a piece of plastic on the top of the pacemakers metal case that provides the point of connection between the pacemaker and the leads.

WHAT IS A PACING LEAD?
A pacing lead is a wire that connects to the pacemaker. It carries the electrical pulses from the pacemaker to the heart. A pacing lead can also relay information about the hearts natural activity back to the pacemaker. The leads are extremely flexible and are very strong. This allows the leads to withstand the twisting and bending caused by body movement and movement of the beating heart. One or more leads are used. The number of leads depends on the type of pacemaker.

HOW IS A PACING LEAD ATTACHED?
One end of the lead is connected to the pacemaker and the other end is attached to the right ventricle or right atrium. A lead can either be placed inside or outside of the wall of the heart. The lead is most often placed inside the heart. This is called an endocardial lead. It can also be described as a transvenous lead because the lead is inserted into a vein that leads to the heart chamber. The tip of the lead is placed against the inner heart wall. Sometimes the lead is attached to the outside wall of the heart; this is called an epicardial lead. With this lead the lead is attached to the outer wall of the heart.