A new study published in the August 2011 issue of US-based cardiology journal HeartRhythm reveals that smokers are at more than double the risk of developing an abnormal heart condition called atrial fibrillation, with former smokers also being 32% more likely than those who never smoked.

http://www.presstv.ir/detail/192872.html
http://health.usnews.com/health-news/diet-fitness/diabetes/articles/2011/08/05/smoking-linked-to-raised-risk-of-irregular-heartbeat-study-finds
http://www.heartrhythmjournal.com/article/S1547-5271%2811%2900305-5/fulltext