Hypertensive response to exercise

[Stew1]

I took a routine physical exam that included a stress test.  Though EKG remained normal and I felt fine, at 13 minutes the tech said that she would stop the test because my BP was 258/78.  Like an idiot, I said that my HR (158) had leveled off and perhaps I could finish the stage.  30 seconds later, BP was 271/76 (HR 159) and the test was halted.  Luckily, I did not have a stroke.

Six weeks later, I took a stress echo, both as follow-up on my CAD and to check for a hypertensive response.  At 16 minutes, my HR of 166 had not changed for 60 seconds, and the test was getting to be not fun, so I asked to stop.  Surprisingly, maximum SBP was only 176 (no change in meds).  EKG and echo were normal, and I felt no pain.  I would greatly appreciate it if you could please answer a few questions:  Should my exercise BP be investigated further?  Had I run to the point of exhaustion, would the test have been more sensitive?  Would there have been a significant risk?  On a stress echo a year ago (a month after a stent was placed), max HR was 176.  Should I be concerned that my max HR has apparently fallen 10 BPM in just one year?

Some background that may be relevant: I’m male, 62, 5’6”, 135 lb., strong family history of heart disease, never smoked, lifelong physically active, healthy diet. I have never had any heart disease symptoms, but a screening stress test in Jan. 2007 showed 3.7 mm ST depression.  A coronary CT scan was also positive, so I underwent angiography.  There was 90% blockage mid RCA; a stent was placed.  Severe stenosis also found at several points in circumflex; to be managed medically.  I’m taking daily: HCTZ 12.5 mg, lisinopril 10 mg, Zetia 10 mg, Lipitor 40 mg, aspirin 81 mg.  With these meds, BP at rest is consistently normal, last test showed LDL-C 59, HDL-C 69, TG 60.  Unmedicated (and with poor diet), my SBP was typically 130-140, cholesterol as high as 315.

Previously posted this (unanswered) in another forum by mistake, sorry.

[Cleveland Clinic]

I am surprised that your heart rate reached 176 bpm. Your maximum heart rate is 220-age (62)= 158. Take this hear rate to be your maximum heart rate and do not exert beyond this level. In fact given the fact that you still have coronary artery disease ( the multiple areas in you circumflex), part of the medical therapy is to keep you heart rate and blood pressure under control. In other words you should not exert yourself to the point where your hear rate is even over 125 bpm or so. And if your blood pressure is elevated with this reduced exercise level, the you need an increase of you present prescriptions or new medications altogether.

[runnertom]

Interesting question. I also have been said to have exercise induced hypertension based on treadmill tests. I think the peak I have seen has been 230/100 several years ago. I have CAD also and had a double bypass 5 years ago for an occluded LAD and first diagonal. This was suprising at age 54 after 30  years of serious runnng and cycling along with what I thought was a healthy lifestyle, acceptable cholesterol, and normal bp. I was suspicious that the exercise induced hypertension might have been at least a contributing factor due to the many hours a week that I am at elevated heart rate. Also, I found a journal article chronicaling a marathon running physician who also had significant CAD in his early 50's who had exercise induced hypertention. It was the contention of the authors that it was likely the cause of his disease.
   However, I have researched the issue at length and found evidence that at max exercise in trained men, SBP of 210 to 230 is the norm. To answer the question for myself, I enrolled in a cardiac rehab class and had them check my bp at varying levels of exertion. The significant finding was that bp tended to shoot up rather quickly as I started exercising, but if I did an extended warmup at heart rate of 110 or less, it reached significantly lower levels at the greater exertion. My assumption is that the dilation of the blood vessels in the working muscles dilate during warmup and reduce bp.
   I have felt for a long time that the Bruce protocol often used for the treadmill testing advances the work rate so fast that you don't get a proper warmup. The test is optimized to get people through it quickly instead of finding their max work rate. For its intended pupose of diagnosing heart disease, I have no problem with this. Is it possible that this warmup phenomena might be responsible for the apparent disparity between treadmill and stress echo in your case?

[sumitra19]

I am not a doctor but have read a lot on blood pressure. I also thought that is normal for BP to increase during maximal exertion.   In fact there was some research done at John Hopkins whereby they put some people with moderate hypertension who weren't on medication and apparently at maximal exertion, their SBP went up in to 250 and higher for some. It was an unusual but not uncommon exercise response and apparently this kind of response may be an indicator that these people may develop severe hypertension at a later stage.

[runnertom]

   I would like to take issue with a couple of comments in the doctor's reply. I am not medically trained but have done extensive reading and as a CAD patient, have had advice from a number of cardiologists.
   Maximum heart rate varies significantly from individual to individual. The 220 minus age formula is only an approximation or average. Individuals often vary +/- 10% from this. My own max at age 60 is in excess of 175 verified by treadmill testing. Often, people who have been very physically active demonstrate a higher max.
   While in cardiac rehab I was told to keep HR below 150 but when they saw I was quite comfortable at that level and my max was much higher, I was released to go to 160. This was 6 weeks after CABG. Subsequently, my doctors have told me there is nothing wrong with running but most advised against racing. The theory is that during racing, one tends to run very close to max heart rate for long periods and may otherwise push themselves beyond what is prudent.
   Obviously, someone with unstable plaque in the coronary arteries is at somewhat increased risk for events during exertion. My contension would be however that most men by age 60 has some degree of plaque buildup whether symptomatic or not and many may not be on statins that tend to stabilize the plaque. If someone with demonstrated CAD is advised to keep pulse below 120, this advice should also be given to everyone reaching that age. If your max is 165, HR of 120 is only 72% of max, barely into the aerobic training zone.