What Causes Dizziness, Lightheadedness And Dyspnea While On Acebutolol?

Posted on Wed, 21 Sep 2016

Question: I have been having intermittent episodes of shortness of breath and tachycardia/palpitations for over a year. (My resting heart rate is normally 60s but it would elevate at different times) I was seen by pulmonology and the only thing they found was a low DLCO. I had many cardiac tests and the only thing they found was a flat blood pressure response during stress/exercise tests and an exaggerated heart rate response. For example: When I would go up 2 flights of stairs my heart rate would go from 70s to 130s. Sometimes even higher. So they started me on Acebutolol. It is definitely helping with the palpitations. I barely feel my heart beat, when before I could feel it a lot through out the day. However, now when I walk up the stairs I no longer feel my heart beating through my chest, the rate only goes up a little bit, yet I feel horrible! I feel lightheaded, dizzy, shortness of breath and have chest tightness. (I had some of these symptoms before the acebutolol but they seem even worse now-I thought it would be the opposite.)

So here is my question: Could the acebutolol reduce my cardiac output causing me to feel this way?
None of my doctors have been able to explain why I have such an exaggerated heart rate response when going up stairs or an incline. I used to work out regularly including the stair climber, so why now is it so hard for me to do? And why did my heart rate go up so quickly with minimal exertion?

Answered by Dr. Benard Shehu (1 hour later)

Brief Answer:
Following advice

Detailed Answer:
Hi and thank you for asking!
I read your query and understood your concerns.

What you are experiencing especially dizziness, lightheaded and dyspnea are side effects of Acebutolol use and aren't related to reduced cardiac output.

To have tachycardia is a common responce to exercise induced adrenaline release. Excessive adrenaline release in minimal physical efort is a sign for poor athletic capacity.

Trained athletes have high tolerance during exercise and release minimal adrenaline in order to perform physical activity. On the other hand untrained athletes release excessive adrenaline in order to do physical activity. People with limited (or poor) physical activity release an exacerbated amount of adrenalin causing tachycardia and othe rof your symptoms.

If you were my patient I would have switched from Acebutolol to Metoprolol (betaloc) to control exercise induced tachycardia (this will have avoided most of the side effects).

Hope this will be of help!
Wish you health!
Dr. Shehu

Note: For further queries related to coronary artery disease and prevention, click here.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar