Archive for September, 2010

Beta Blocker Blues

September 28, 2010 1:20 pm
Beta Blocker Blues

I knew something was not quite right with my body from early this year. Although I was still climbing relatively fast for a 62 year old, my times were not at last year’s level. Could it be that age is finally knocking at the door? Or am I just not training hard enough?

I was on track with my training for the Hoodoo 500 bicycle race, a 519 mile race I am doing at the end of August as part of a two man relay team. I had just finished the 12th week of my 19 week training program, with 384 miles that week on the bike, 6 miles running and over 25,000 feet of climbing.  I was finally feeling prepared with the distance but my speed was still not quite what I was expecting.

Beta Blocker Blues

It is now over two months later.  After many medical tests, I finally have the green light to push hard again but  I am now taking a beta blocker to reduce high blood pressure that is triggered by exercise.  It has the effect of lowering my heart rate and makes cycling and running harder than before.  Today I did my intervals on a bike that include 7 minutes very hard, followed by 3-4 minutes recovery, repeated 4 times.  I have done this same course over the past two years and have several data points.  Today’s results were the slowest of any, averaging only 19.8 mph, and my average heart rate during the interval sections was only 132 bpm, showing the effect of the beta blocker.  Before my average speed ranged from 20.5 to 22.5 mph with an average heart rate in the 155-165 bpm range.

If you want more background on the events that have lead up to today, you can read the details below.

Initial Problem

We were in Utah and Anne was up for a climb up the Alpine Loop on July 12th, 2010. After making our way up the Provo Canyon trail, then up to the highway to the intersection for the Alpine Loop, I told Anne to go ahead and I would wait 5 minutes, then push hard up the first section to Sundance. My best prior time this year on this 2.3 mile segment with a 900 foot climb was 15:32. I had not been able to do better than that since May. But today I pushed hard and climbed it in 14:34 but that required an average heart rate of 164, maximum of 172. As you can see from the graph below my heart rate was in the “Anerobic Zone” (152-165 bpm) for the first half of the climb and in the “Red Line Zone” (165-178 bmp) for the later half of the climb, typical for when I am trying to set a new PR on this length of climb. For more information see my article on heart rate zones.

I then rode the rest of Alpine Loop with Anne and then back down to our Utah home. That was now 38 miles of biking but I felt I needed more, so I decided to ride on my own and do Squaw Peak and South Fork. It was now getting warm and my plan of doing Squaw Peak was a good one, but the decision to push the pace and try to see how fast I could do the climb may have been too much. I was taking my heart rate up high, especially near the top of this 4.3 mile climb with 1,700 feet of elevation gain. Later I could see I had an average heart rate of 167 for the climb, with a maximum of 174. You can see from the graph below that I was spending most all of the time in the red line heart rate zone. The poor visibility on my Garmin Edge 500 makes it hard for me to read my heart rate so I did not realize at the time I had my heart rate so high.

Near the top I felt this pain in my left shoulder, but otherwise I felt okay. After descending back down to the Provo Canyon trail, I got some water and rested for while. The pain was still there but I didn’t seem to have any other issue so I finished my intended ride. As the day wore on, I was surprised the pain in my shoulder did not go away, even after several hours. I checked my pulse rate and that seemed normal. Later that night I thought maybe I should check my blood pressure. However the only device we had at the condo was a simple blood pressure monitor that goes on your wrist. I was alarmed when I got a reading over 180, especially since I usually have normal blood pressure.

Visit to Emergency Room

We called our neighbor and borrowed their blood pressure monitor and I took it again. It was 184/110. Now I was really alarmed, enough to decide we needed to get some medical attention. At 11 pm, that meant a trip to the emergency room.

The doctor said they needed to run some tests, so they took a blood sample and then did an EKG.  Both were negative so they did a chest xray then a CT scan with some type of fluid injected into my blood stream. Awhile later the doctor came in to say that the  test was also negative. Now it was about 3 am, and there was no reason to stay at the ER, so we returned home. The doctor suggested I contact my personal physician and schedule a stress test since the testing they did was all without being under stress.

After returning to California, I paid a visit to our personal physician.  After showing him my blood pressure readings, he prescribed a low dose Ace Inhibitor medication and refereed me to a Cardiologist for a stress test.  I started to take the blood pressure medication on the next evening, July 27th . Although the information with the prescription said it takes 2 to 4 weeks to take affect, it had an immediate impact and starting the next morning, almost all blood pressure readings have been in the normal range, even on the low side.

Stress Test

On Monday, August 2nd, I was glad that I would finally get a stress test. Although I have continued to bike, I have tried to keep my heart rate below 140 as a safety precaution. They hooked me up to something like a EKG machine and then the doctor came in. I explained much of the above history to her. I showed her the details of my blood pressure readings that I had kept for the past 10 days.

It was easy for me to walk, then run on the treadmill. As my pulse rate increased, she would periodically take my blood pressure. I noted that my blood pressure was starting to go up rather high. When I reached a pulse rate over 150 bpm, she asked how I felt and I said I was fine and could keep this up for hours. When my pulse rate reached 163, my blood pressure went to 230 so she decided to end the test.  That was alarming when I realized that I routinely gone higher than a heart rate of 163 when I push hard on a hill climb.

There was an indication on the EKG that my heart muscle had been thickened. Several years ago I had visited the same cardiologist when something in an EKG had indicated something and she had done an echo-cardiogram back then and found it was borderline. She said the primary cause of this heart thickening is high blood pressure and believes I may have had the issue for some time and I became tolerant to the high blood pressure while exercising hard.

I called David, my Hoodoo 500 partner, to give him the whole story. I said I was fine if he decides to do it solo, or do it with a different partner and if he decides either of those, I will crew for him. I received a call back a day later and David said he would do the Hoodoo 500 with his wife, Deb, as the partner. Although I was disappointed that I could not put all my training to use, it did give me some sense of relief to cut back on my training until this medical problem could be resolved.

Echo Cardiogram Results

On Thursday, August 5th, I went in for an echo-cardiogram. This is essentially a sonogram of the heart.  When I visited with the doctor on August 10th, she told me the echo exam showed no enlarged heart but there had been some further thickening of the heart wall, which is usually caused by high blood pressure.  She prescribed a new medication, a beta blocker and to stop taking the ace inhibitor.  It seems that the beta blocker is more effective at keeping your blood pressure down while your heart rate goes up.

Nuclear Stress Test

On September 16th, I went to the doctor’s office to have the nuclear stress test. It took about 3 hours total time. First they connected an IV to me so they could inject the nuclear isotope. After making the first injection, they had me wait for over 20 minutes, then I was placed on a bed that had some type of camera system rotate around me. I asked how it worked, and I guess it takes about 60 pictures, that can be used to form some type of 3D image.

After that I went to the treadmill and had a similar stress test conducted by the cardiologist. Once again she was measuring my blood pressure during the test and she commented it was not going abnormally like before. I went about one minute further into the test than last time and they then injected more isotopes into the IV, then stopped the treadmill. This time my blood pressure had only risen to 200, a more normal value than then 230 last time. So this was the effect of the beta blocker.

During a follow-up visit with the doctor on September 21st, she showed me the images from the nuclear test and said things looked fine, no blockage of the arteries. My next visit is in 6 months. She said I can go ahead and push hard again on the bike. I am just not sure how fast I can go considering being on the beta blocker.

After having so many tests, I need not worry about my heart. That is the good news.  I am very fortunate that I found out about this issue because many people whose blood pressure only goes up during exercise never know about their condition since blood pressure is always taken while resting.  For now I need to stay on the beta blocker so I don’t expect to set any new KOM times on my hill climbs, but at least I can now push hard again and not worry.