Arrhythmia Alliance
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What is the difference between a pacemaker, ICD and S-ICD?

Pacemakers are fitted when an abnormality in the electrical pathway of your heart upsets your heartbeat and causes it to beat irregularly. Artificial pacemakers treat some of these abnormal rhythms and help improve your quality of life.

An ICD (implantable cardioverter defibrillator) might be fitted to prevent arrhythmias from deaths from sudden cardiac arrest (SCA). If your doctor has suggested that you need an ICD you may have experienced or may be at risk of experiencing an abnormal, fast heart rhythm. An ICD constantly monitors your heart rhythm and can deliver various electrical impulses to correct potential problems. It is made up of a small pulse generator, contains a battery and electronic circuits, and sophisticated leads that connect the generator to the heart. And ICD, like a pacemaker, is usually placed under the skin below your collarbone.

An S-ICD (subcutaneous implantable cardioverter defibrillator) is a more recent invention. S-ICD's are able to defibrillate the heart with only a lead that is placed just beneath the skin instead of into the heart. They are not suibable for all patients.

What are your experiences with these devices?

2 Replies


My quality of life very much depends on my pacemaker - without it I'd not be able to live the life I live. It 'replaces' my sinus node as well as my AV-node as both have been ablated, and therefore it also needs to adjust my heart rate to all kinds of exercises and activities. Without my pacer, I'd be alive, but definitely not kicking ;)

I have benefitted a lot from the optimization of my pacemaker's settings. There is a lot doctors can change to adjust the device to individual needs. My cardio has been very patient, and has "tweaked" my pacer until we found the best settings for me. Unfortunately, as I have recently been told by a representative from a pacemaker manufacturer, in many patients these settings are never optimized, either because the doctor does not know how to, does not have the time to, or because it's expensive to have a patient come in again and again. The rep said, up to 70%-80% of the pacemaker patients never get an optimization. So, I'd encourage everyone who has a pacemaker and feels like something's not quite right, yet, to ask for adjustment of settings.

Best wishes



Thank you for the advice on optimisation of pacemaker settings. I have had a dual chamber pacemaker (Boston Scientific Ingenio DR model) fitted last November and go back for my first review next week. It has not produced the "immediate benefit" I was expecting, so probably needs some tuning. I will make a list of all of my continuing symptoms and the circumstance when they occur, and hopefully the correct adjustments will be made.

kind regards, Mallet-head


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