Hi! Folks,
The purpose of this post is to encourage you to gather data if you are dealing with an abdominal aortic aneurysm (AAA), with or without an endovascular stent graft, or any other life-threatening condition for that matter. You never know, it might help.
Remember my early posts about how I discovered my abdominal aortic aneurysm? Much like Pauline [see comments], I noticed an abdominal pulse combined with an unexpectedly poor race performance. I also mentioned that when I went in for my stent placement, which probably saved my life already, I was normotensive (130/80), and a few weeks after the stent placement my blood pressure was 195/105 mm Hg. Never had that before, ever!!
I’m just coming out of a blood pressure (BP) funk, thus the gap in my posts over the last week. I thought that my post-AAA-stent BP problems were over, because a few months ago I was fooled by insufficient data, and not paying attention, into thinking that things on the BP front were fine. A week ago I went for a routine medical check and my BP was at 190/105 mm Hg, which immediately made me think of stroke, heart attack, blindness, and lovely things like that. It also frightened my family and friends, especially the two nurses, to death; they wanted to cart me to the Emergency Room, and we’ll see if they were right. As a researcher by nature, I ran some more measurements on myself, to find that my BP essentially hovers around 180/100, with a resting pulse 10 beats per minute faster than my usual 39-41. Interesting what this kind of information does to what I like to think is a calm, rational brain. Sure!!!!
I expect to be dead one day, but not yet, so my reaction over the following week went like this: (1) dismay, (2) panic, (3) literature research, (4) more panic, (5) frustration with apparently slow medical system [but it is me that is panicking, not them, so I am not rational at that moment and they have many other priorities, and the wheels are in motion. That said, you still have be your own advocate, but not annoy as that slows things down and is not encouraging of rational thought], then (6) calmer thinking and analysis of the situation, and finally (7) realization that I need more information on the behavior of my hypertensive vascular system, i.e. I need more data. Such data might help my much appreciated medical professionals decide what to do if they are listening (which I hope they are!), and equally importantly it gives you a feeling of taking control, whether that is true or not, and such a feeling will lower your blood pressure.
After purchasing a high quality, ‘wrist blood pressure measuring device,’ using Deb as negative control (115/75), I then established that my resting but high BP is pushed up further by environmental stress to around 200/110, and it is lowered slightly by sleeping on my stomach instead of my back (read this somewhere). I then did some simple experiments with an n (group size) of one (Tim Ferriss approach) which appeared to demonstrate that (a) beets, known as beetroot where I come from, had no effect, and here’s the data:
Time HR Systolic Diastolic
Pre-Beets
7:15 pm 56 179 92
Post Lots of Raw Beets
7:45 pm 54 175 95
8:15 pm 54 184 108
8:45 pm 53 173 95
9:15 pm 52 179 99
9:45 pm 47 177 100
Woke up the next day hoping for salvation by beets
5:30 am 58 191 109
No change! As a scientist I should repeat it three times, but I couldn’t look a raw beet in the face if I tried, plus all my bodily fluids are bright red, making me wonder if I have a bleeding disorder, so I move on:
(b) rest didn’t help, (c) caffeine still needs more work, and I am doing that [bummer], and FINALLY (d) exercise consistently reduces my blood pressure, whether biking or running. Here is an example data set:
I rest after waking up slowly, and then measure BP before climbing on my trainer bike (my old friend Quintana Roo, with Power Cranks and Computrainer!). Ride indicated as minutes x Wattage:
Time HR Systolic Diastolic
Pre-Ride
7:00 am 51 181 102
During Ride
7:10 (10′x85W) 87 169 91
7:20 (10′x120W) 98 160 84
7:30 (10′x140W) 112 170 79
Not statistically strong, but it happens every time. Best result was a systolic BP of 136. I now plan to work on optimizing the load times time response - got to give my heart and cerebral vasculature a break while my doctors work out what to do!
Yesterday I ordered a new Guru triathlon bike from Victor, as I plan to keep up my Ironman training for a long time to come.
Happy Friday,
KevinImportant Note: These posts do not provide medical advice. You should always consult your physician before undertaking or significantly modifying an exercise program.
Copyright © 2010 Kevin T. Morgan aka FitOldDog, Old Dogs in Training, LLC.
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Hi,
Interesting blood pressure data, and a coincidence that I was also looking at my variation with exercise today. One question, what were your values pre-stent? Also, is it the case that it is the diastolic one that is important in hypertension, and systolic varies throughout the day? For comparison, mine is normally 120/80 and I have a correlation with heart beat (on a treadmill) of:
(bpm, d,s): (50,128,82), (53,112,76), (79,130,64), (98,144,80), (123,158,80), (153,174,80), recovery (92,158,90), (63,114,80)
The BP goes down initially, as does yours, then goes up as the effort increases. I considered just running slowly to keep the BP down (less stress on Albus), but since it is only systolic that varies significantly, and only for the time exercising, I think I’ll continue running intervals!
Hi! Pauline,
Thanks for your comments and the data. Very helpful!
1. Prior to my stent I had no history of hypertension and my resting pulse hasn’t been over 45 for several years. Since my stent most of my measurements, two of which were in doctor’s offices showed a significantly high BP and HR. After I recovered from AAA-stent surgery, I noticed that my heart was laboring all the time, which I put down to compliance changes in my high-pressure system. This feeling has been slowly diminishing since then, but it never goes away completely. I am going to see another cardiologist on Wednesday, and I am hoping that someone will get to the bottom of this so that I can get on my training for LPIM. I am going to do more load-BP experiments to find the optimal BP lowering wattage/duration, as that seems like a good thing to do. I’ll put worthwhile observations in posts to this site.
2. I was planning to research diastolic versus systolic issues, but off of the top of my head I would say that the concerns are: (a) high systolic pressure could blow an aneurysm in my brain or elsewhere, or weaken the seal around the anterior end of my AAA-stent as the systolic pressure wave-induced expansion of the elastic laminae hits the anterior margin of stent which is not so elastic, whilst (b) my concern about a high diastolic pressure would be impaired blood supply to the cardiac muscle which is perfused during diastole [clever trick that!], due to increased compression of the capillary bed. I could have this all wrong, as I am no cardiologist. I think I’ll post this question on ‘The Athlete’s Heart Blog’ and ‘Cardiac Athlete’ once I’ve had my second morning cup of tea.
When it comes to workouts that induce a high systolic pressure, be careful, as your AAA could be fragile. I think that it is not so much the load as the rate at which the load is applied. It is clear that vascular bed resistance drops with exercise, at least in some places, but this takes a little while. So! I would gradually increase load based on experiments. I was planning to try immediate load (say 160-200 Watts) versus ramping up gently, to see what my maximum systolic pressure is in each case. We should develop a protocol for this approach, designed to minimize systolic risks, as we are all a little different ‘cardiovascularly.’ Let’s see what we can find in the literature, and evoke from various chat rooms.
Bottom line, in my ill-informed opinion - gently ramp up the load before your intervals.
Cheers,
Kevin
Kevin, I sent you an email with this. Below is an abstract from PubMed of an in vitro AAA/stent graft model demonstrating (quite convincingly) that both rigid and non-rigid stent grafts induce hypertension (HTN). -EB
http://www.ncbi.nlm.nih.gov/pubmed/17360221
Med Eng Phys. 2008 Jan;30(1):109-15. Epub 2007 Mar 13.
Evidence suggests rigid aortic grafts increase systolic blood pressure: results of a preliminary study.
O’Brien T, Morris L, McGloughlin T.
Centre for Applied Biomedical Engineering Research and Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.
Abstract
Abdominal aortic aneurysm (AAA) is a serious complication of the aorta and is treated using vascular bypass grafts. Two main classes of graft are available to treat AAA; grafts implanted by open surgery and stent-grafts implanted using minimally invasive endovascular techniques. Both classes of graft consist of an aortic section which bifurcates into two iliac sections. It has been hypothesized that implantation of aortic grafts and stent-grafts serve to significantly increase abdominal aortic pressures. In this study, an open-loop computer-controlled pumping system was built to produce physiologically realistic pressure and flow-rates. Models of a compliant abdominal aortic aneurysm, a compliant walled graft and a tapered graft were manufactured using an injection moulding technique and fused deposition modelling was used to create a rigid walled graft. A specific transient flow-rate waveform was then applied at the inlet of each model and the resulting pressure waveforms 30 mm upstream from the bifurcation was recorded. Peak pressure measurements were recorded over the course of the pulse for each model. The compliant aneurysm model was found to have a systolic pressure of 107 mmHg while the complaint graft model was 153 mmHg. The rigid graft model had a peak systolic pressure of 199 mmHg. In the tapered graft, the peak pressure dropped to 142 mmHg. The data suggests that implanting a graft model in place of an aneurysm model in an in vitro flow circuit can increase the pressures recorded upstream from the iliac bifurcation and that tapered grafts may alleviate this problem.
Hi! Eric,
This abstract, which I failed to find in spite of extensive searching, is very much appreciated. The information provided opens doors to a rational approach to therapy. I have contacted the authors of this abstract for comments on my hypertension, in addition to communicating with a number of other vascular physiology researchers, including Raven (see article in today’s post). It is surprising how much this abstract has reduced my state of tension.
Very much appreciated, and I look forward to your coaching.
Thanks!
Kevin
My mother had the Endurant Stent by Medtronic placed for her AAA in January of this year. Prior to surgery, she always maintained a good, healthy BP most often on the lower end of normal. After the stent placement, her blood pressure has topped out around 220/118. She was hospitalized about 4 weeks post-op for stroke like symptoms (slurred speech, confusion, severe headache, etc..). She was placed on BP meds and now averages a BP of 165/90 or so. She still continues to have headaches on occasion and was most recently hospitalized for chest pain and shortness of breath. Heart tests checked out ok…but they still have not done an MRI (or CT -not sure which test they use) to check the placement of the stent. She now was found to have
blocked carotids but surgery has been postponed due to the issues with her BP. Our family is 110% convinced that her issues with high blood pressure are directly related to the placement of the stent, however the doctors are reluctant to agree. We were told of all the risk and benefits to the stent rather than open surgery, but were never told that this could cause high blood pressure. Would be interesed in hearing from others who have experienced this….Thank You!
Hi! Concerned Daughter,
Thanks so much for this information on your Mom, as her situation exactly parallels mine, including the highest post-stent BP (220/120) and the degree of diminution of BP with meds, to the 160/90 range. Mine was further corrected by consistent training at fairly high level, which brought my BP to normal or highish normal. I also had no pre-stent history of hypertension, in spite of regular annual health screening. I posted my AAA-stent-induced hypertension information on this blog, previously. We now, I think, have sufficient evidence to suggest that AAA-stent grafts can induce hypertension, which should be investigated further, and certainly should be prepared for before surgery, and addressed after surgery by regular BP checks. I will inform Medtronic and Cook of this issue. Thanks so much, and I’ll keep you posted on their response.
I am grateful for my stent, which most certainly saved my life, as my AAA was about 7 cm in diameter, and one look at the CT convinced me to get this treatment ASAP. I think that in my case it was life saving. I failed to convince three cardiologists that my stent had induced the hypertension. The potential for effects on BP make total sense if you think about the underlying fluid mechanics and related the regulatory circuitry, plus the evidence from the laboratory in Limerick (see cited article in my previous posts!).
Very much appreciated, and best wishes to you and your Mom!
Kevin Morgan