Dual Chamber pacemaker impacting Ejection Fraction Ratio


I had a Boston Sceintific Dual chamber pacemaker installed in Nov 2019 due to 2:1 heart block. Post pacemaker implant, a PET/SCAN revealed inflamamtion in heart for which I got a Prednisone & Methotrexate treatment. Although the inflmamtion is now completely gone after 1.5 years recent echo revealed that my Ejection fraction ratio dropped to 45% from 60% (at the time of pacemaker  implant). Also teh 2:1 block has now changed to full block., so pacemaker is used 100%.

 Doctor is advising to go for change in pacemkaer to bivertinicular as they think sometimes dual chamber pacemaker being used 100% can impact left side being out of sync. Has anyone gone through similar scenario. Does CRT treatement really helps. I am also on medication (beta blocker and ACE inhibitor). Does medication help in increasing EF ratio or do I have to go for CRT. Thoughts?


Biventricular Pacemaker

by Caratacus - 2021-09-30 07:12:43

Hi, similar circumstances to yours. I'm 80 years old and a lifelong distance runner but now with CAD, leaky valves and persistant afib. Dual chamber pm implanted in May this year (2021) as a result of being tachy/brady. At this time EF was 55%  Four months later EF had dropped to 45%. I do not know to what degree I'm being paced, but my Electrophsyologist is considering a pm upgrade to biventricular as the next step. I am also on Bisoprolol, ace inhibitors and small dose Digoxin and that keeps my afib ventricular responce under control. My issue is the lack of exertion tolerence due to afib and heart remodelling. From what I'm reading a biventricular pacemaker coupled with lifestyle changes - physical activity, weight loss, cutting out alcohol, sodium and stress - can put your EF back in the 'Green'. Good luck.

upgrading to bi-vent

by Tracey_E - 2021-09-30 09:17:00

Yes, it's possible that the pacing has caused your EF to drop. It's also possible that it's from the inflammation and other factors. 

Going from 2:1 to 100% block is very normal. Block almost always progresses and most of us with block end up pacing every beat. 

45% is just under normal, so low but not terrible. Is it affecting your ability to do what you want to do? If you feel good, I would keep an eye on EF but not be in any rush to upgrade until your current one is ready to be replaced. I would not want the extra surgery unless I felt bad or my rate was a lot lower, like under 35%. 

Ejection Fraction (EF)

by Gemita - 2021-09-30 10:55:43

Hello NKG,

Right Ventricular pacing can sometimes lead to a drop in EF and cause heart failure symptoms to occur, but it clearly doesn’t happen to everyone who is paced 100% in the Right Ventricle.  I would want to be sure of the diagnosis before I went ahead with CRT.  I believe an EF of less than 35-40% is usually the level at which an indication for CRT pacing is recommended.

Does medication help in increasing EF or do I have to go for CRT you ask?  Lifestyle, medication and CRT can all certainly help to improve EF but it can take time to see results, so don’t expect an immediate recovery, although some can have an immediate response to treatment, but it depends on what other conditions you may have.  

I am assuming your doctors have ruled out other reasons for a fall in your EF like coronary artery disease, diabetes, high blood pressure, ongoing inflammation?  Whether a 45% EF should be treated immediately with CRT would depend on the doctor and on your symptoms.  Deteriorating symptoms and signs of heart failure like fluid retention, breathlessness, fatigue would definitely be a cause for concern, but if you are otherwise well, without noticeable symptoms, an EF of 45% may not be significant and may even recover to more normal levels with a change in medication, diet, in lifestyle alone.

I would question your EP in more detail.  You might want to ask about other forms of imaging, perhaps an angiogram to rule in or out heart disease first, or for further assessment of your EF.  If you have no symptoms, you have time to consider all your options.  I wouldn't rush into anything.  If you have difficult symptoms, then I would perhaps consider CRT for better synchronisation between your ventricles, together with lifestyle changes.  Good luck and I hope you come to the right decision.

Reduced LVEF

by AgentX86 - 2021-09-30 22:33:00

As others have said, this isn't unknown.  It's calld "Pacemaker Induced Cardiomyopathy" or PIC.  Generally it's not considered a problem unless the LVEF gets down to 30-35%. Often insurance won't cover a CRT pacemaker until it gets to that level. Your EP should be your source of information.  He'll know more about your options than we will.

Reduced Ejection Fraction

by nkg - 2021-10-01 01:05:48

Thanks everyone for valuable feedback. I forgot to mention that after the doctor first noticed reduced EF they ordered an angiogram as well which came more or less normal. One of the artery showed 40% block but they said no need to put in any stunts etc.  I have been measuring Blood pressure, heart rate, weight after starting my medication which has been more or less normal. The medication I started were Beta blocker and ACE inhibitor. Its been only about 5 months on these medications. The doctor said for medication to work it is a combiation of 3-4 medication taken over 6 months before you see any result. I dont have any major symptoms apart form feeling tired only sometimes. 

I have my apoitments with EP next week, will discuss options. Good point about insurance, let me check on that as well. 

Thanks for the inputs. 




by PacedNRunning - 2021-10-02 04:31:36

I too had 2:1 block that progressed to persistent high grade block. So I went firm intermittent pacing to 100%. My. EF went from 68% to 53% at almost 3 years post implant. My EP told me if it drops below 50, I will be upgraded to a CRT P. He said I do not have to be 35%. 35% is non pacer induced cardiomyopathy but pacer induced is less than 50%. We did a exercise EF since I run. It was 60% so we will repeat my resting echo one year from the 53% and see where I'm at. Luckily my lead is placed well so hopefully it will stay above 50%

Dual lead to CRT pacemaker

by Aberdeen - 2021-10-02 14:32:28

I had a dual lead pacemaker implanted in January 2020 due to bradycardia. Heart rate 35-40 bpm. In May 2020 I collapsed at home. In hospital I was told that the left side of my heart was out of synchronisation with the right side and I would need a CRT pacemaker. I was told this was caused by my dual lead pacemaker. Fortunately for most people this is an uncommon occurrence. My ef was around 35-40. In October that year I had an echocardiogram and my ef was 63! I am on low dose Bisoprolol, Ramipril and aspirin to thin my blood.

I have felt quite well. I wish you good luck if you have a CRT pacemaker.


worked for me

by dwelch - 2021-10-09 10:05:17

I wont assume it works for everyone but it worked for me.  They watched my EF for like 15-20 years and when it dipped into the 30s it was time for a biventrical which I got a few years ago.  And my EF did rise as a result of the biventrical.   Again, I would not assume that is for everyone, and 45 aint that bad I dont know if mine was ever that good.

You know you're wired when...

You can proudly say you’re energy efficient.

Member Quotes

Pacemakers are very reliable devices.