Pacemakers & Implantable Cardioverter Defibrillator (ICD)
Pacemakers

Pacemakers
A pacemaker is a small device that sends electrical impulses to the heart muscle to maintain a regular heart rate. In general, pacemakers are not very effective for preventing A-Fib and are not specifically used to treat A-Fib. A pacemaker does not cure A-Fib. But they can be of benefit to some patients. Newer dual chamber pacemakers can possibly terminate A-Fib episodes with pacing and supress Premature Atrial Contractions (PACs) from triggering A-Fib by overdrive pacing.
Implanting a pacemaker seems to be most helpful if you have a slow heart rate or pauses (5+ seconds) as a result of taking A-Fib medications. But there is a danger for patients with this approach. A slow or even very slow heart rate usually doesn’t cause any harm. As for heart rates, “normal” is indeed a wide swath. Some people, particularly athletes, can have a very slow heart rate and be perfectly healthy. The same holds for asymptomatic pauses.
In the words of Dr. John Mandrola:
“Do not implant pacemakers in patients with non-symptomatic bradycardia (slow heart rate).1
Non-symptomatic slow heart rate or pauses don’t justify exposing patients to the risks of implanting a pacemaker. Another consideration is that implanting pacemaker leads in the veins of the upper chest often prevents or hinders future procedures that require vascular access like a Pulmonary Vein Ablation/Isolation (PVI/A).
A pacemaker usually isn’t implanted unless your heart rate is too slow2 or you have Sinus Node and/or Atrioventricular (AV) Node problems. But be advised that pacemakers tend to have bad effects over the long term, “…a long-term morbidity (is) associated with a pacemaker.”3 Leadless pacemakers seem to have less complications than traditional ones.
For more information on Pacemakers, you may want to visit the pacemaker chat site: pacemakerclub.com. (Thanks to Mara for alerting us to this site.)
[I admit to not knowing much about pacemakers. Happily one of the A-Fib.com’s contributors installs pacemakers and offers the following observations.
“I like to tell patients who receive pacemakers that, after a couple of months, they can have a VERY active, normal lifestyle. All of the current pacers have a “rate responsive” mode, meaning they are designed specifically for activity. The more active you are, the faster the pacer goes. Three triathlon runners, and two NFL players have pacers. Most people forget they have a pacemaker.
A recent trend is to implant the ventricular lead on the septum vs. the right ventricular apex, which gives better cardiac output and a more ‘normal’ heartbeat. You might want to ask your doctor about this possibility. Even if your doctor does not prefer this technique, he/she will be impressed that you did your homework.
In addition, you always want a dual chamber pacer which will give better cardiac output. It will also attempt to synchronize between the atria and ventricles, unless the patient is in Chronic A-Fib. If the A-Fib is intermittent, the pacer will temporarily switch modes to VVIR (ventricular only pacing) during the A-Fib, and then back to normal DDDR (dual chamber) pacing when the A-Fib terminates. This is all done by the device memory/logic program.
So, during A-Fib, the DDDR pacer will switch to VVIR and pace only the ventricle during the A-Fib.”
Key to the acronyms.4
Implantable Cardioverter Defibrillator (ICD)


An implantable cardiac defibrillator (ICD) is a device that is put within the body and is designed to recognize certain types of abnormal heart rhythms (arrhythmias) and correct them by delivering precisely calibrated and timed electrical shocks, when needed, to restore a normal heartbeat.
Having a defibrillator implanted in your heart is, from the point of view of most A-Fib patients, not a probable option. A defibrillator shock is painful, like being “kicked in the chest.” Most people would rather have A-Fib than risk being shocked throughout the day and night. Also, it does not address the underlying problem or condition of your heart that causes your A-Fib.
Fewer than 10% of patients get shocked when a shock isn’t needed, according to Edward K. Kasper, MD of The Johns Hopkins Hospital..5 In another study 18% of patients with A-Fib received inappropriate first shocks.6
More than 30% of people who have ICDs develop emotional problems such as anxiety and depression—in part due to worry and uncertainty over whether the device will deliver an unnecessary shock and the fear of being shocked.7
What’s it like living with an ICD and A-Fib? Roby T. shared:
“The worst part was the ICD firing,” he recalls. “It hit me like a baseball bat and knocked me over.” His wife, Mary, was afraid to leave him alone. And the anxiety levels took their toll, even during sleep. “He became really anxious expecting a firing at any time,” she says. “You could see the fear in his eyes,” she reluctantly remembers. “He had to start taking antidepressants.”8
Our A-Fib.com pacemaker expert writes:
“Defibrillators are far more complicated (than pacemakers). When people report getting a big shock (500-700 volts) from the unit, that was probably for V (ventricular) Fib, not A-Fib, if the unit is programmed properly.
One good thing about the V-Fib is that it is usually (not always) proceeded by Ventricular Tachycardia, a much slower, organized rhythm that often responds to painless anti-tachycardia pacing. We will attempt anti-tachycardia overdrive pacing for several different patterns before we finally give up and go to the full output shock.”
Last updated: Friday, December 25, 2020
Return to Treatments for Atrial Fibrillation
- Mandrola, John “Choosing wisely: The electrophysiology list of five don’ts http://www.medscape.com/viewarticle/802018↵
- “Atrial Fibrillation Educational Material” University of Pennsylvania. 2002, p. 3.↵
- Prystowsky, “Should atrial fibrillation ablation be considered first-line therapy for some patients?” Circulation 2005;112:1214-1231, p. 1228.↵
- Key to the acronyms used in the Pacemaker quote:
“DDD” signifies a dual chamber pacer, capable of sensing and pacing in both the atrium and the ventricle
“VVI” is ventricle only
“AAI” is atrium only
“R” signifies Rate Response, a programmable on/off feature which increases the pacing during activity↵ - Kasper, Edward K., MD. The Johns Hopkins Hospital,”How to Save Your Life If You Have Heart Failure.” Bottom Line Health, May, 2012, p. 9.↵
- Cesario, D. et al. The Role of Atrial Fibrillation in CRT-D Patients: The ATTITUDE Study Group. The Journal of Innovations in Cardiac Rhythm Management. 6 (2015), 1873-1880.↵
- Kasper, Edward K., MD. The Johns Hopkins Hospital,”How to Save Your Life If You Have Heart Failure.” Bottom Line Health, May, 2012, p. 9↵
- Roby’s Arrhythmia Story. Published on MyFastHeartBeat.com Last accessed November 5, 2012.↵