Reined in by rehab - what's going on?

[LadyZ13]

Quick background - I had a large atrial septal defect diagnosed in December and have been referred for surgical closure,which should be in the next few months.

I have had no symptoms from the ASD - been cycling, running and bootcamping, then skiing in January. Obviously my heart isn't 'normal' but either it's compensating really well, or I'm just used to it??

A blood clot snuck through the hole 2 weeks ago and got stuck in a small coronary artery, causing a heart attack. I was put on blood thinners and the usual raft of heart-recovery drugs and was sent home after 2 days.

Yesterday I went to a cardiac rehab appointment to help me in my recovery. I was put on the treadmill atttached to the ECG and BP monitor, and my heart rate was gradually brought up. The test ended after about 10 minutes. I was told my blood pressure had dropped quite dramatically when my HR got to about 110bpm. I didn't notice any change in myself when this happened. As a result, I've been told not to let my HR get above 95bpm for the forseeable future.

I'm gutted by this - last week I was walking up to 3 miles a day and my HR would typically get to 120 as we are fairly brisk walkers. I also cycle to work and this would normally see my HR above 100 through most of the commute. The rehab team say once I have surgery the issue should resolve, but they also didn't know what would cause my BP to drop like that - it's probably not a result of the medication and more likely to be biomechanical. In the meantime, I face months of significant physical restrictions (for me) which is really difficult when I feel OK - and it's impacting my fitness ahead of OHS.

Has anyone else had experience of their BP dropping during exercise? Did you ever get answers about why? I'm curious to get to the bottom of this!

[LadyZ13]

Hi there! Thanks for your reply and sympathetic words.

The ASD was diagnosed after I passed out at work. It wasn't a cardiac collapse - attributed to stress, but a chest x ray showed an enlarged right side of the heart which triggered further investigation. Before that I was lifting heavy weights in the gym and doing HITT training with no ill effects. I guess it's always been like this for me, so it's my 'normal'.

The BP was measured with a cuff attached to the same machine that was doing the ECG, and inflating every 2 minutes. My BP rose with my heart rate (which it is supposed to) but then went back down to 120/80 which was deemed unsafe so the test was stopped. I was on a treadmill throughout so it was carefully controlled. I think it was the sudden drop that was the concern. I've never had BP issues until now, even on the medication. It's weird!

[LadyZ13]

As it happens, I know exactly how much plaque I have in my proximal LAD, but wonder if the rehab team were aware.... it's 25-49% blocked, as picked up by a CT and a coronary angiogram during the HA. So it's there but shouldn't be at the point where it causes a HA just yet, and the huge statin dose I'm now on should help stablise it...

If a septal defect can be a cause of the drop then I'd assume it's long been something happening for me that I've just not been aware of... Rehab has said they'd speak to my consultant so maybe that'll give us a new perspective?

Thanks for helping me understand this

[LadyZ13]

Yes, I was a bit surprised! I don't eat a great deal of fatty food or salt, but there is high cholesterol in my family. Mine's not actually that high (4.5) but still worth tackling given the blockage - consultant wants me to get it below 3. Who knows, maybe the blockage is closer to 25% than 50%. The first CT I had, the doc said there was some mild calcification but it was probably in line with my age - but they don't normally investigate people under 40 - so as you say, there's not much data for people who go on to develop issues in later life.

I'd probably trust the readings at Papworth - but that said, they did keep needing to hold my arm up to take the readings while I was walking, so it wasn't the most straightforward process... But I can only go on the info they've give me!

[LadyZ13]

Thanks for the additional insight. I wonder if rehab talking to my consultant will help. They've also suggested I come in for a bike test, which with the additional medical background might give them more confidence that I'm not in danger or being harmed. Rehab are going to call me weekly to see how I'm getting on, which is good!

[LadyZ13]

I'm sure you're right. I'm just impatient and so, so aware that I'm going to be out of action for an extended period after surgery, and exercise is a big part of keeping me sane so I was hoping to enjoy it while I can. But if there are risks of overdoing it, even if unconfirmed, that's better to rein it in rather than flirting with further disaster.

[Chappychap]

"As it happens, I know exactly how much plaque I have in my proximal LAD, but wonder if the rehab team were aware.... it's 25-49% blocked, as picked up by a CT and a coronary angiogram during the HA. So it's there but shouldn't be at the point where it causes a HA just yet"

The relationship between degree of plaque blockage and risk of heart attack isn't that simple. There are plenty of people on this forum who have had arterial blockages well above 90%, but have never had a heart attack. Conversely there are others with plaque levels too low to be accurately measured, but who have experienced multiple heart attacks.

Different people seem prone to laying down different types of plaque, some have more unstable plaque that's liable to rupture and cause a heart attack, others have plaque that quickly calcifies and is therefore more of an angina risk than a heart attack risk.

You're right to say that statins can help stabilise plaque, but this is a slow process and far from guaranteed.

Finally, the specific issue you mentioned was an ejected clot rather than ruptured plaque. That might suggest an elevated stroke risk.

Frustrating though the prospect is I'd follow the medical advice and stop exercising. You mention wanting to maintain fitness ahead of open heart surgery. But your relatively young age and existing fitness mean that your risk profile is far lower than the average patient, and your recovery is likely to be commensurately quicker. I wouldn't do anything to darken that bright prospect.

Incidentally, you sound like someone inclined towards evidence based decisions. You may want to investigate EuroSCORE II, which is the "bible" for open heart surgery risk evaluation. Furthermore, the principal architect of this study, the British cardiologist Samer Nashef, has written a book about how it was developed. It's a fascinating read.

Good luck!

[LadyZ13 in reply to Chappychap]

Hi Chappychap, thanks for sharing this.

I guess I'm trying to play down my worry about CAD because I'm currently focused on surviving the OHS for the ASD repair. I hear what you're saying about HAs happening in people with lower levels of blockages (presumably any blood clot could be big enough!) and will be mindful of that, plus the time for the statins to work. The comments I'd had so far on here were fairly positive about my outlook on the CAD side so I guess I've been leaning in to those!

They've yet to determine where the clot came from - it was veinous and indeed I could have had a stroke had it taken a different path once it snuck through my ASD. I've been referred for genetic testing to look at my clotting factors, and they immediately took me off the combined pill as that comes with a clot risk.

Wow, Euroscore is a bit terrifying! I wasn't sure what my procedure would count as; it might be a ASD repair and valve repairs too, which at 'two procedures' puts the risk really a lot higher than I was told. Eek. And the while I've had a heart attack, it wasn't a 'traditional' episode due to narrowed arteries. Not really sure what to make of that. Could I be forgiven for ceasing my own evidence-based research and trusting the doctors? 😬

[Chappychap in reply to LadyZ13]

I'm sorry if I've alarmed you, my intention was the exact opposite. The biggest single risk factor for open heart surgery is age. The average age of an OHS surgery patient is late 60's, I think from memory it's 68. Which makes you an astonishing thirty years younger than the average. That fact alone swamps everything else.

Then remove any of the common co-morbidities, such as T2 diabetes, that many OHS patients have and which drives up risk and delays recovery, and you're in a very good place.

[LadyZ13 in reply to Chappychap]

Thank you - I appreciate that intent. I was surprised to see my survival rates better in all cases had I been born male 😅 Maybe I'll stop playing with it now - but it's a very clever and very useful tool to someone in the right headspace for it. And I will take that reassurances that the odds are mostly in my favour!