Cardiac Pacemaker

Cardiac pacemaker is a device meant to give regular electrical pulses to the heart when the normal pacemaker function of the heart is defective. The normal pacemaker of the heart is the sinoatrial node (SA node) situated in the upper part of right atrium. It gives out regular electrical pulses to the heart at a rate between 60 – 100 per minute. These pulses are conducted down the right atrium to the atrioventricular node (AV node), which is the relay station for the pulses. In the AV node the pulses are delayed and sent further down the conduction system known as the bundle of His and bundle branches (right and left) into the ventricles. The delay ensures completion of atrial emptying prior to the onset of ventricular contractions. This helps in better filling of the ventricles. The basic electronic pacemaker consists of an electronic circuitry to generate the pulses, a battery with long storage life of the order of several years and a set of leads to convey the pulses to the heart. The battery and circuitry are housed together in a hermetically sealed metallic container made of biocompatible material which will not induce a foreign body reaction in the body. This part known as the pulse generator is usually implanted under the skin under local anaesthesia. Modern pacemakers have highly complex circuitry capable of monitoring the body’s requirement and varying the pulse rate accordingly. They are also communicating devices which can transmit the stored information...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: ECG / Electrophysiology Source Type: blogs