CT angio or MR angio

[Dentalmaniac]

Since the last 8 years i've been concerned about my heart health, due to irregular heartbeats and MVP. About a couple of years ago, I noticed that i get upper back pain with excercise. Went to a cardiologist who did nuclear stress test which came out negative (i did not walk for 15 minutes which is when my pain would normally start). With that he gave me a clean bill of health and i was somewhat satisfied. About six months ago, that pain changed into chest pain with excercise. Went to cardiologist who did another nuclear stress test which came back negative again. Please note that my pain would start after 15 minutes of excercise, but each time for the nuclear stress test, they made me walk no more than 8-9 minutes. About a couple of weeks ago, I noticed the same pain when i was out in the hot weather. Since then i've felt this pain more frequently (each time with exertion or when i'm in the heat). Went to my doctor who told me to get a holter monitor. He told me that the next test he would order for me would be a ct angiogram (which involves radiation). My question is I definitely want a sure answer to my symptoms, however do not want to go through more radiation. Would an MRA (magnetic resonance angiogram) be able to detect Coronary Artery Disease? Should I request an MRA rather than a CT angio, or should I be going with the cath? Please advise