Hi, I'm currently really worried about my heart. My resting heart rate is 42 bpm. My doctor sent me to a cardiologist when she saw this, and I've had multiple EKGs and a heart ultrasound. Everything came back normal. I run cross country so I'm running anywhere from 5- 8 miles everyday and the cardiologist said this is probably why my HR is very low. However, I can't stop worrying that it's too low and have been getting anxious during practice worrying about sudden cardiac arrest. I'm constantly worrying about pushing myself too hard out of fear that my heart can't handle it. Is it possible that I could go into cardiac arrest, especially since my heart rate is so low?