35 years old male. Normal weight. No history of cardiac disease. Blood pressure usually under 120/80. Normal cholesterol. Non smoker. No alcohol. No coffee.
Blood pressure medication (enalapril 10mg/day) because of glomerulonephritis I had in 1991 and 1997. Currently no trouble with kidneys -- kidney function normal, no protein in urine etc.
1mg Xanax/day and 30mg Remeron/day because of generalised anxiety disorder I developed this spring.
My resting heart rate is usually 50-60bpm. I have seen it drop as low as 42bpm in rest. Normally my heart rate is in 70-80bpm range when I walk around the house for example. It goes to 110-120 range on a brisk walk or to 130 when I climb up stairs to the third floor.
However, I have begun to experience following symptons lately: my resting heart rate can be as slow as 50bpm, but when I get up and walk even a little, it shoots up to 100-120 range and stays there as long as I'm up. If I go lie down, the heart rate slows back to "normal" resting rate rather quickly. Climbing up the stairs can bring the heart rate over 150 now!
I've had blood tests for thyroid function, heart enzymes, hemoglobine, crp etc. and they all came back normal. Also I had a resting ecg that indicated: "sinus bradycardia - otherwise normal". (I had heart rate 50bpm during the test.) I am also scheduled for a 24h holter monitoring in two weeks.
What could possibly cause such a huge increase in heart rate? I should be in a fair shape, since I used to walk 1,5h daily, but now I'm afraid to exercise, because of the high heart rate.