There is such a thing called "holiday heart." If you check the emedicine site, they talk about high alcohol intake and the risk of atrial fibrillation.
Wow that is a heavy duty question.......the risk of sudden death and arrythmias due from alcohol abuse are fairly remote however you have to remember that with overdoing it with the alcohol which is a depressive causes your whole system to slow down and depress everything in your body....if you are in a stupor from the alcohol and you suddenly have issues with your heart you would not have the capability to recognize what is going on with you therefore putting you at a higher risk because you would not be able to get the help you need if you have a pre exisiting heart issue. The two do not mix....especially if you are on heart meds. You would be playing Russian Roulette with your life by abusing your body like that especially if you do have heart issues....