Lopressor vs Exercise

I've been taking 50mg of Lopressor twice a day since my heart attack in December 2002. The Lopressor apparently prevents my heart rate from exceeding 125 bpm, even during a stress test. Since my heart attack I have been doing a lot of biking to try to strengthen my heart but my fitness level doesn't seem to improve much no matter how many hours I spend biking,

Is it possible that the Lopressor is preventing me from improving my fitness level? Are the benefits of taking the Lopressor outweighed by it's effect on my heart rate?

Thanks in advance, Howard

...and weight loss (which should probably be listed first).

Servant to the humblest person in the universe,

You are welcome, Howard.


Servant to the humblest person in the universe,

Then I would be concerned that your fitness problem is coming from progression of your ischemic heart disease.

How's your HgbA1C been this whole time?


Servant to the humblest person in the universe,

Fwiw, a paced heartbeat is a little less efficient than a "natural" heatbeat.
For the same heart rate, the cardiac output may be significantly less for paced heart rhythms compared to "natural" heart rhythms. This may be what is actually underlying your "fitness level."

Servant to the humblest person in the universe,

Dr. Chung, Roadcyclist,

Thanks you for your quick replies!
I biked about 1800 miles and walked several hundred miles during the summer months. The hills were almost as difficult to pull at the end of the summer as they were at the beginning. Based on previous my biking experience I expected steady improvement during the season.

During this winter I worked out daily on a bike trainer or treadmill for an hour or more a day and so far I biked about 300 miles this year.
Again I've seen no real improvement. During the longest climbs and fastest sprints I have been unable to raise my pulse rate above 125. Most of my bikeing is done in a fairly hilly area.

Since the heart attack I've had several stress and echo tests. My heart function had been above average on all but the first echo test which was done shortly after the heart attack. During the stress tests I've have been unable to raise my pulse rate above 125. My doctor and the folks at the heart hospital attributed this to the Lopressor (50mg twice a day).

I believe I will be taking Lopressor for the rest of my life because of the good effect it has in preventing additional heart attacks. At the same time I have been told to exercise vigorously to prevent additional heart attacks. The two seem to be at odds with each other. The Lopressor
"seems" to be preventing me from increasing my fitness level. Maybe this is ok if the Lopressor is protecting my heart in a way that is more important than being fitter?

I had a pacemaker installed in February 2003. Except for a brief interruption to my exercise program the pacemaker has not affected my maximum heart rate.

Dr. Chung, an echocardiogram indicated no problem and in fact indicated that my heart efficiency is above normal. It is not that I can do less but I cannot seem to improve. Much of my bike riding is over the same route. From past experience I would expect the hills to become easier to climb and for my time over the route to drop.

Since Lopressor decreases the workload on the heart by slowing the heart rate and decreasing the force of the contraction I thought that this might also make it difficult or impossible to improve fitness while taken

The results for all HgbA1C tests have been between 6 and 7.

Stress tests are designed to detect macrovascular (occlusive atherosclerosis in the epicardial coronary arteries) but not microvascular disease. Moreover, echocardiograms are better at detecting and quantifying systolic dysfunction rather than diastolic dysfunction. Microvascular disease primarily manifests as diastolic dysfunction *before* systolic dysfunction develops. Diastolic dysfuntion can impair fitness just as easily as systolic dysfunction.

Worsening ischemic heart disease at the level of the smaller vessels is equally plausible.

Do you have metabolic syndrome (MetS)?

Servant to the humblest person in the universe,

So far I have avoided the typical eye and foot problem associated with diabetes.
diagnosed 20 years ago (weight 265, high blood pressure, normal LDL, low
HDL, insulin resistant, no or little exercise). Now my weight is 185 (
6'2", low blood pressure (115/65), low LDL (50), high HDL (47), low trig (45), and I exercise 1.5 hours daily. The changes were brought about by a combination of diet changes, medication and exercise.

My heart attack occurred in December 2002, the pacemaker was installed in February 2004 (not 2003 - my typo). My fitness concerns occurred between the two events and after the second event.. The pacemaker implant did not change my fitness problem other than to cause a four week layoff from serious exercising.

The pacemaker was installed to correct an autonomic neuropathy related (vagal/vagus nervous system) problem caused by diabetes. I had an echo test the day the pacemaker was installed. The test results indicated that my heart function was above average.

Thanks for sharing, David.

Servant to the humblest person in the universe,

Dr. Chung, installed in February 2004 (not 2003 - my typo). My fitness concerns occurred between the two events and after the second event.. The pacemaker implant did not change my fitness problem other than to cause a four week layoff from serious exercising.

The pacemaker was installed to correct an autonomic neuropathy related (vagal/vagus nervous system) problem caused by diabetes. I had an echo test the day the pacemaker was installed. The test results indicated that my heart function was above average.