Elaine Eaker et. al. published an interesting study in Circulation in 2004. It followed 1769 men and 1913 women from the Framingham Offspring Study. It showed that after adjusting for known risk factors such as age and high blood pressure, researchers found several traits significantly increased the risk of atrial fibrillation in men. Those with higher feelings of hostility were 30 percent more likely to develop atrial fibrillation compared with men with lower hostility levels. No correlation was found in women.
Here is the full article:
Here is the link to a ScienceDirect comment on the study.
Meditation may help.
Thich Nhat Hang has written a good book on anger.