Have Atrial Fibulation, Sinus, Cardioverted. What Effect Would Pot Smoking Have On My Condition?

i have atrial fibulation, i have been cardio verded 5 times, to resume normal sinus rythym. 4 times before having a cyroabation done sept 5, 2012. i went into afib on jan 9 2013 while working out and took a multaq and reverted in about 40 minutes ( 1st time without cardioverison), yesterday i went into afib and was cardioverded again, i am confused and feeling depressed about my future, even when im not in afib, many days my heart seems to pound hard at times, i had a heart cath done on oct 19, 2012, one artery had a 50% percent blockage, which they said was no big deal, i am 57 years old, dont smoke (ever). i cant drink alchol because of the afib, what effect would pot smoking have on my condition? i smoked pot in my teens and 20 s but rarely since, i m asking because i need something to take my mind off the constant worrying, i would prefer alcohol but they say i cant do that