Cardiac Pacemaker

The rhythmicity of the heart beat is based on the electric impulses. These impulses are initiated by the contraction of the cardiac muscles also known as myocardium. These impulses are initiated by the specialised cells situated at specific location within the myocardium; these cells are known as pacemaker cells as they main the pace (speed) of the heart beat.
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Our myocardium is made up of special cells known as cardiomyocytes and they have an intrinsic property to generate electrical impulses. The conduction of the electrical impulses leads to action potential or change in potential energy which is responsible for propagation of the impulse down the entire myocardium. Thus, during the entire cardiac cycle consisting of contraction and relaxation there is change in the action potential and the electric impulses can be tapped and measured. The 1% cardiomyocytes in the myocardium have an ability to generate this action potential, The portion in the heart that possess the specialised cells that generate and propagate the impulse is the pacemaker cell and is called Sino atrial node. (SA node). The SA node is situated on the walls of right auricle (atrium) from where the impulse for the contraction sets in.

Sometimes, there is injury to these specialised cells or the portion of the heart which results in impaired impulses leading impaired cardiac cycle in terms of rhythmicity, force of contraction and its periodicity. In this case the heart is controlled to beat at a particular pace with the help of an external device. Such a device is known as pacemaker and the pacemaker mechanically generates electric impulses so that the heart can beat continuously at a regular interval.

A pacemaker is a small device that's placed in the chest or abdomen controls abnormal heart rhythms and makes the heart beat at regular intervals. This device uses low-energy electrical pulses to prompt the heart to beat at a normal rate. Increased pulse than the average beats puts lot of stress on the cardiac functions leading to fatigue and finally heart arrest. Such disorders are known as cardiac arrhythmias. During an arrhythmia, the heart beats with an irregular rhythm or at a faster pace or at slower pace. Pacemakers relieve arrhythmia symptoms by normalising the heart rhythm.
Pacemakers help restore the normal rate and rhythm of the heart and reduces the fatigability of the heart muscle. Pacemakers provide a new lease of life to the patients suffering from heart rhythm disorders and help them lead a normal active daily life.
Cardiac pacemakers are the external devices that help the heart t beat normally. Any injury to the area where the device is implanted or physical blow that can damage the device can be fatal. Patients thus need to exercise caution in their movement and also wherever required and indicated follow the working conditions of the pacemaker. One must visit the doctor periodically for the calibration of the pacemaker and to evaluate its working.


  • Are all palpitations arrhythmias?
    No; the increased number of heart beats is response to the increased work load after a physical activity such as climbing strains, running etc. In case of arrhythmias, the heart has abnormal pace and rhythm even while an individual is resting and has symptom of fainting, confusion, excessive fatigues and needs immediate medical supervision.
  • Do pacemakers last lifelong?Pacemakers have long life (at least 5 years from the date of implantation). The electric impulses are generated with the battery system and hence the batteries need to be replaced every 2-3 years. The lasting period of the battery is indicated in the pace maker and your cardiologist shall advice and guide you for the same.
  • What specific precautions are needed to be followed by the patient after the pacemaker is implanted?Pacemaker is a device and is generally safe. One must avoid being in the areas with high magnetic fields as they can affect the functioning of the pacemaker. Use of cell phone, diathermy in physiotherapy, using of headphones should be avoided.
  • Are there specific travel advisories?It is generally safe to travel with the pacemaker. However, the security detectors can damage the pacemaker and it must be informed to the security personnel not to hand-held the metal detecting wand over the pacemaker for more than a second.
  • Can one lead a normal life after the pacemaker? This device is not an impediment to daily life. However one must seek doctor’s advice for the exercise regime, driving, returning back to work and normal activities like before, participating in sports activities such as running, swimming etc. and the sexual relationships. It is important that once should avoid any blow to the area near the chest region and over the device as it can severely hamper the functioning of the pacemaker. In case of such accidents see your doctor immediately without any delay.
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