Propranolol?

Question

Suppose a person has propranolol before severe exercise, how will it change his endurance to exercise ?

Answer 1

It depends on the cardiac status of the individual. With exercise, cardiac output needs to increase, and that can be done by increasing the amount of blood the heart pumps with each beat, and by increasing the number of beats per minute.

Propranolol will impair the body's ability to increase the heart rate. If an individual is unable to increase stroke volume, the heart may not be able to meet the demands that exercise is putting on it, impairing endurance.

(SAMI, there certainly ARE false positive stress tests, as evidenced by nuclear imaging. Symptoms do not always mean ischemia, which is why the nuclear portion of the test is done.)_

Answer 2

Aha! A trip down memory lane!
Twenty-odd years ago I actually had a young man consult me after having started propanolol (from another doctor) for hypertension. His complaint was that when playing baseball, he could no longer get to first base. He'd simply give out of steam. The degree of exercise intolerance is quite variable, though, and many people never exercise vigorously enough to notice a difference.

Answer 3

Non pharmacologic stress testing (e.g. Bruce Protocol) is notorious for missing tissue in jeopardy, particularly in patients who can't achieve target BP & HR double product, e.g. elderly population, women, etc.

False Positive stress tests 2ndary to diaphragmatic creep or say, for instance, breast attenuation will lead to countless angiograms to be performed. Hence, this is a screening test.

I agree that this is highly dependent on the underlying cardiovascular status of a given patient.

Answer 4

It will marginally improve exercise tolerance. But false positive treadmill exams do not occur. Symptoms like breathlessness and pain confirm ischemic heart disease.