My name is Dr. Vallabhan. I am a Board Certified Interventional Cardiologist. I am going to discuss the various aspects of pacemakers and defibrillators in a concise fashion. I am going to give three examples of when patients are candidates for the same.
A pacemaker is meant to treat slow heart rates and rhythms. A defibrillator is designed to shock people out of rapid heart rates and rhythms that could be fatal.
These systems may be a single lead device, two lead device or three lead device. Leads are insulated metal coils that are threaded through veins to reach the heart. Typically this vein is located under the clavicle and is called subclavian vein. A device is a battery that generates the impulse to stimulate the heart.
Our first example is an 88 year old lady with black out episodes and falls. She is found to have a very slow heart rhythm and periods where her heart stops for up to 10 seconds at a time. She is a candidate for a pacemaker to improve her symptoms and also prolong life. Her heart as a pump is normal. She will typically receive a single lead or two lead device for this purpose.
The second example is a 72 year old active man who suffers a large heart attack. He is found to have a low pump function. His heart as a pump is working at around 30% (normal being 60%). This value is also said to be the ejection fraction. He however does not have any symptoms. He is a candidate for a defibrillator and will receive one if he is willing. This is done to treat fast heart rates, which may cause sudden death. His low heart function puts him at risk too. This has been shown to improve longevity.
The third example is a 55 year old man with a weak heart. He is found to have a weak heart muscle and he does not have any other coexistent that could be causing this. His ejection fraction is 28%. He has a lot of shortness of breath with minimal exertion. His ECG is also abnormal. He meets criteria for a special type of pace maker that will coordinate his heart to function better and pump better. He is a candidate for cardiac resynchronization therapy. An extra lead is placed in a specific site in the heart and this helps in making it function better. Also given his weak heart he is at risk for the fast heart rates and it’s consequences and he will also have a defibrillator incorporated in the device. This is designed to improve quality of life and also improve longevity. Some older patients with this condition may refuse the defibrillator to avoid the shocks.
All the procedures clearly have benefits. There are risks involved with implantation of these devices. I believe that tailoring therapy to individual needs is most important.
Dr. Vallabhan | 352.750.2040