My doctor put me on propanolol for a high heart rate in 2022 and it made me feel terrible. A week after starting it, I had a 24 hour Holter monitor and every time I got startled, I had a heart block. Example, when my alarm went off in the morning at 6:30. The cardiologist said maybe I have high vagal tone or I am very in shape. But my primary care told me I have low vagal tone and that’s what’s causing my issues and why my heart rate was out of control . I am not an athlete. I can barely do anything without my heart rate shooting up. I stopped the propranolol and followed up with a month-long heart monitor two weeks later. I did not have another heart block. They are suggesting another beta blocker. I am hesitant to try it and wanted to get a second opinion on whether this was a normal response to such a low-dose of beta blockers. Thanks to anyone that reads this