Last year my beta blocker dose was doubled and I found I couldn’t exercise for 2 minutes before I became short of breath and legs ached. My BP and heart rate were also ridiculously low so I researched alternative supplements. I halved my bisoprolol and added Hawthorn and COQ10. I can exercise again and so far am arryrhmia free. I wouldn’t suggest anyone tries this as could be harmful but I do believe in researching and educating ourselves and questioning docs re medication.