 I am Dr. Rajneesh Sardana, I am the head of Pacing Electrophysiology Department at the Manipalad Institute, Varkha, New Delhi. The topic today I am going to be discussing is about cardiac implantable electronic devices which encompasses basically three kinds of devices. One is a pacemaker, the other one is a defibrillator and third is a heart-filling device. I am going to be basically differentiating between a pacemaker and a defibrillator. Pacemakers are by and large devices, small devices which are put into the body and they take care of the heart rate of preventing them from coming below a certain degree. So the heart becomes slow, pacemakers are there to back up the pulse by giving an electric impulse into the heart and not allowing the heart rate to drop to below 30, below a certain degree which is usually 50 beats per minute or 60 beats per minute. However it can do nothing in case a patient's heart beats go high and they get life threatening. Defibrillator is a device which is implanted again inside the body, the lead goes into the heart. It has a capacity to give a shock internally in case the device thinks the patient's life is at risk. So if the heart rate goes very fast and the blood pressure drops, the device has the capacity to diagnose bad rhythms, so-called ventricular rhythms and detect them and charge the capacitor and shock and revive a patient. So this is the basic difference between a pacemaker and a defibrillator where one takes care of slow heart rates, where the other one takes care of the high heart rates and has the capacity to cardioid or DC shock a patient. Defibrillator also have a backup pacemaker in it, so they also take care of slow rhythms preventing any patient from dropping the heart rate to below a certain degree as I said again below usually 50 or 60. This is the basic difference between a pacemaker and a defibrillator.