Rate Adaptive Pacing (Accelerometer) for Orthostatic Hypotension (OH)

Ive been suffering from orthostatic hypotension for the past couple of years. Had my pacemaker put in 1.5 years ago for 2:1 block but it didnt help with OH. I saw a new EP (dept chair) a couple of days ago. Unfortunately his fellow did most of the workup so cant say Im all that confident in what he did.

From what he described it seems he turned my accelerometer sensor on to max. So much for fine adjustments and a light touch lol. Now when I stand my heart rate jumps from set point of 70 to 110-130. Seems to make me feels worse.

Anyone else have any experience with rate adaptive pacing? Maybe it's too sensitive? Maybe a max hr should have been set. Gonna test it out for a week and see but looking for ideas and experiences. thanks!!


pacing and OH

by Tracey_E - 2023-10-04 16:12:15

I wouldn't expect the fix for heart block to also fix OH, unless part of your problem was pauses. The pacer can make sure you don't skip beats, but if your bp drops it's not going to do much. 

If your rate jumps up that much on standing, ask them to make it less sensitive. There are a lot of settings between off and max! Perhaps he thought having your rate jump that fast would help with bp and prevent a drop? I'm just guessing here, no facts whatsoever to back me up lol


I'd be surprised if it helped much

by crustyg - 2023-10-04 18:15:16

My understanding - quite possibly wrong - is that the cause of OH is lack of venous supply to the heart in most cases.  So increasing HR probably won't do a great deal to increase your BP since each ventricular fill will be smaller than needed.

As it happens I get something that's similar to OH, made much worse by bending down as this constricts the vena cava, and having an increased filling pressure due to stiff heart muscle just makes it worse.  For other reasons my PM's accelerometer is set to be fairly sensitive into the Rate Response algorithm (such that turning over in bed at night gives me a noticeable tachy for a while), and I don't feel it's made any difference to the mild faintness I get from bending over or squatting for a long time whilst gardening.

orthostatic hypotension

by Selwyn - 2023-10-04 19:12:03

Whilst the heart may cause a drop in blood pressure on being in the vertical position, there are other causes eg. medications, dehydration, neurological illness, anaemia, and glandular problems.

I would be wanting a full  medical assessment of my problem ( I well remember a young man with recurrent fainting who had Addison's Disease). Look further than the heart for a cause.

As discussed above, the rate response  settings are adjustable for time of onset and offset as well as upper rate. I have recently had my rate of onset reduced and feel tons better walking up stairs without having my heart thumping. 

I have recently helped a relative with this problem by recommending full length support hosiery ( stockings). Medication being his problem ( betablockers and diuretics). There is medication you can take for orthostatic hypotension, if needed, eg. fludrocortisone- this needs some carefull medical supervision.

Leading on...

by Penguin - 2023-10-05 05:51:52

Leading on from Selwyn's post above: 

Bob, I see from one of your previous posts that you were taking Citalopram 40 mg for 20 years?  I think you said that you are trying to reduce it / stop taking it.  How is that going? 

Several SSRIs lower heart rate to some degree and some have more potential for cardiac effects than others.  For example there was a large research study in 2012 which found that Citalopram / Escitalopram in 40/20 mg doses and upwards was strongly linked to cardiac side effects.  This was taken seriously by medicine worldwide and warnings now exist re: Citalopram above this dose. 

Citalopram as you will know is an SSRI (Selective Serotonin Re-uptake Inhibitor).  Serotonin levels in the body will increase when you take it. Functions affected by the drug or altered during long term use (?) may waiver when you withdraw from the drug or swing to extremes if titration is too fast. 

Serotonin has lots of different functions in the body, but two which may be relevant to you, are vasodilation and vasoconstriction e.g. the widening and tightening of blood vessels.  These functions are probably fairly essential when maintaining healthy blood pressure. 

It may be worth discussing this drug with your doctors. I enclose a brief article re: Serotonin and the vascular system. There are many others.


This is a well reviewed paper on antidepressants and BP.  Citalopram gets pretty good press in it re: effects on BP.


This paper discusses pacing strategies for vasovagal syncope


Spanner in the works

by piglet22 - 2023-10-05 06:45:05

If only all these discussions could be had with the medics in the UK.

My heatth trust might be bad in comparison to others, and UK practice is different to US or others, but I can't see any prospect of being able to discuss problems with the cardiologists other than after a lengthy wait.

The GPs do their best, but stumble whem pacemaker is mentioned.

As far as medication goes, as I'm finding out, there are complex interactions going on with beta blockers and ectopics and PMs which all take time to sort out and that time is in short supply.

In an ideal world, you might be able to get advice fairly quickly and get on with your life, but realistically, that's not going to happen.


by Penguin - 2023-10-05 07:23:47

The availability of good quality research to your doctor plays a big part in discussions once you eventually get to the point where you can have a conversation. 

ADR reporting (and the lack of) is a major flaw in the feedback system. It can take years for side effects to come to light from a sufficient amount of affected patients if they are not consistently reported. 

As a patient you can raise a side effect / withdrawal effect with your doctors and not be taken seriously because it seems as if you are in the minority or a lone case.  It's a big problem for doctors as well as patients.

Complex issues are really frustrating piglet.  Nobody has time to listen atm.

Thanks for all the helpful input

by bob53 - 2023-10-05 13:36:24

Great feedback per usual from the fourm!

OH does have a number of possible causes, and partial solutions, of which Im trying many mentioned above. Hydration, electrolytes, smaller meals, more protein, getting up slower, compression stockings, tapering off citalopram etc.

Reversing my anemia and taking Butchers Broom (Alpha agonist) may have helped the most to reduce the numbers and severity of the BP drops but am still symptomatic.

The research on rate adaptive pacing for OH is somehwat mixed. Some papers show no effect and others show a big effect. I think it depends on the individual and the PM technology (CLS pacing showing best results).

As far as getting doctors to spend the time to fine tune the PM and understand all the relevant research, I agree it's a crap shoot. For example, not one of my many primaries, cardiologists or EPs have mentioned that citalopram may be an issue, despite there being a long time FDA black box warning on it causing OH.  The cynic in me suspects that drug side effects are a feature and not a bug. Polypharmacy seems to be all the rage.

The EPs are capable but dont spend the time to really adjust and test and readjust until they get it right. My new EP is even worse, as he did a classic bait and switch. His Cardio Fellow did all the work while he came in for the final 5 minute pep talk. Its like medicine has gone full MLM.

Autonomic Nervous System Specialist

by Penguin - 2023-10-05 14:56:29

If the cause is Citalopram and you are titrating the drug from a 40mg dose, it may be worth consulting a specialist in the Autonomic Nervous System and requesting Citalopram in liquid format. 

Titrating this drug after long term use is fraught with difficulties if you are affected (some people breeze through it, others suffer).  There is research around which suggests that long term use is one of the main predictors for difficult withdrawal. 20 years is definitely long term! 

Liquid Citalopram can be used rather than reducing using tablets. This allows for a much slower taper and this can help avoid symptoms such as OH!!


yes, slow tapering is a must

by bob53 - 2023-10-05 16:47:51

Right now Im tapering at 3% a week. Any faster and I feel the symptoms. Some good website forums on this for anyone else trying. Unfortunately at  this rate I wont be citalopram free until 2025.

Im using a mg scale but liquid citalopram is something to look into.

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