Men who cheat on their wives more likely to die of a heart attack Your cheatin" heart makes Hank Williams weep, but it might kill you. Researchers in Italy examined monogamy among men and discovered an interesting correlation -- having an extramarital affair increases men's risk of having a deadly heart attack. It's almost cliché: a middle-age man having sex with a woman who is not his wife keels over in flagrante delicto, what's known as sudden coital death (oh yes, it has a medical name). But like some stereotypes, it appears to be based in truth, says Dr. Marc Gillinov, a heart surgeon at The Cleveland Clinic and co-author of the book "Heart 411," which looks at cases of sudden coital death, among other cardiac events. Gillinov did not participate in this study. The researchers -- from the University of Florence -- examined the medical literature related to cheating by searching for "unfaithfulness," "extramarital affairs," "infidelity" and "men." Reliable statistics about cheating are hard to find because most people claim to be morally opposed to cheating and don't chat to scientists about it. The authors report that anywhere from 15 to 25 percent to as many as 30 to 50 percent of men cheat at least once in their lives. Then the researchers looked at a variety of physical and mental health factors and the rates they occur in both monogamous and un-monogamous men. Doctors have long known that men live longer if they consistently have sex into old age, but knocking boots only provides a health boost if it occurs with the same partner in a familiar place. Sex into old age only helps if you're doing it with your spouse. Sudden coital death occurs most frequently when a man engages in coitus with a woman who is not his long-term partner. While scorned wives might believe these results make sense on a karmic level, the authors found them surprising. Generally, cheating men have better hormonal and vascular function, meaning they're healthier than monogamous men (finally, a reason to be excited that your man is a couch potato). But the authors believe that the act of trying to keep an affair secret might contribute to cheating men's increased risk of a deadly heart attack. "It's the added stress of trying to have a secret affair," says Gillinov. You are doing things that you don't normally do. Cheating men frequently have affairs with younger partners and these men feel they have to drink, smoke, and eat more to keep up with their mistresses. All this adds up to increased heart rate, blood pressure, and anxiety, which can contribute to a heart attack. Although, sex itself is no more strenuous than walking up a few flights of stairs. "It's also like there is a medical reason for fidelity," Gillinov says. The article appears online in The Journal of Sexual Medicine.