Thank you for asking on HCM. Normal pulse for adults ranges from 60 to 100 beats per minute, but 58 bpm it s not bad if you don t have any symptom. Slow or irregular heartbeat may be caused from some conditions and diseases, but also from drugs. I don t know the other drugs you re taking but Metoprolol is a beta blocker drug that reduces blood pressure and heartbeats too. So in my opinion an based on the amount of details you have wrote, I suggest you to see your treatment doctor if this persists or is getting severe. A switch to an other type of drugs that reduces high blood pressure may be required such as Enalapril or Losartan. This depends on your medical history and current blood pressure values. Hope this will be helpful for you!