Cardio-type exercise literally scares me
I have/had a heart defect, and when my heart rate increases it stresses me out and causes great anxiety. I probably already had an anxiety disorder/or was prone to it as it seems to be familial (and "fixed" with an SSRI).
A little bit of background: When I was 18 I was diagnosed with Supra-Ventricular Tachycardia. What would happen is: I would randomly and suddenly have a palpitation and my heart rate would jump to 235 (no joke) and would not slow down until I went to the ER to receive intravenous medicine. I've had an ablation, but have not been able to control my rate without a beta blocker since (that was 12 years ago).
Ever since then I've avoided any serious cardio, but now I want to lose some weight. I walked on the treadmill for half an hour and did 3 intervals of running for 1 minute. After each 1 minute interval my heart rate would be at 180, then would slow down to 140 when I would walk again. My cardiologist always seems to poo-poo my worries (probably because I'm anxious). However, it still really scares me.
How much of the 180 bpm is me being out of shape?
Could anyone lend any support.