I've had 3 false alarms over the past 15 years, 2 resulting in overnight stays in the hospital. Each time I ended up getting a nuclear stress test to "clear" me. Like you, I just don't like to take chances. Figuring out the ol' ticker can be pretty tricky though. I only smoked between ages 14-17, have been involved in competitive athletics most of my adult life, and have never been overweight or had high blood pressure. Still, you never know what's lurking. The nuclear stress test doesn't necessarily show you where plaque is building up in your arteries. I went and did one of those Heart CTs recently that scores based on calcium deposits, but apparently they're only a good indicator of whether you're completely clear or totally screwed. Anything in between doesn't really tell you much. My best friend, who was 15 years younger than me, ultra fit, and an MD, died from sudden cardiac arrest at 42. Turns out he had coronary microvascular disease but his only symptoms were some shortness of breath that he attributed to getting "older", and fatigue, which he may have attributed to his new and demanding job as a Chief Medical Officer. @TheXGreat to hear survival stories like yours!