CT Coronary Angio Test. Side effects?

Hi, Looking for a suggestion here.. My husband (29yrs, 92kg, 5"9, non smoker, occasional drinker) is getting some pinching sensation around chest and left arm pain from past 4-5 days and cardio doctor has prescribed "CT coronary angio test" ( non invasive). My husband had symptoms 6months back like increased heartbeats, anxiety and sweaty and underwent - 2d Echo Doppler, trop -T, TMT and all reports were normal back in September 2018. Both his parents have had heart attack earlier. Please let me know if this is a good way to get a clarity here in this case. Does this test have any side effects? Is there anything we need to be aware of / precaution before getting the test done. Thanks, Jadhav