Do you chew gum? I just read an article about a Japanese study. They had the patients chew gum and walk. some only chewed gum, some only walked, and some did both. They found that chewing gum was as effective at raising heart rates as walking. My thought was this...give it a chance. I bought some gum before going to give blood. When I have donated in the past my heart rate has been under 50 and I have been rejected based on that alone. This time while chewing gum my heart rate was 62. Masticating is the answer to getting your heart rate up.
https://www.afp.com/en/news/23/walk-and-chew-gum-it-may-keep-you-thin-study-doc-15c71b2
My pulse has been so low that my cardiologist wants to put a pacemaker in. Worst problem, besides they don't turn them off when you die, is the in event of need for MRI to discover what can be wrong with you (unless they call the company to get a rep in to turn the devise off and then back on again) you are simply out of luck and stuck with die being injected so the tissues show up on CT.

Try walking to raise your heart rate. Carvediol seemed to suppress my heart rate as well.

1.Walk in the sunlight to the max possible extent 2 Learn and Do deep breathing and other exercises.3 Move To Total Plant Based food.4 Meditate and Pray 5 Do Yoga 6 Smile and Sleep well. I was given 12.5 mg Carvediol after heart attack.Now I take 3 .125 mg , twice a day .HR is perfect.I feel palpitations in morning but with Meditation , I become Ok , 90 % Of time.MEDITATION is the Key.