While weight gain has a potential to exacerbate, cause and worsen many diseases, disorders and symptoms of illness, it s effect on Mitral Valve Prolapse and Regurgitation is poorly studied, and to my understanding, there is no evidence to support a strong connection; though each patient may respond to weight gain differently. I will say that STRESS causes a great many issues for the human body as well, including weight gain. With stress, Cardiac issues will often exacerbate/worsen and or present themselves after being previously undetected. Afib and Mitral Prolapse and Regurgitation are connected, and yes stress may pay a part in this process. If you have been diagnosed as overweight or obese, I certainly recommend diet and or weight loss; as there are a great deal of cardiac benefits, other than prolapse, regurgitation and a-fib which can occur as a result. I wish you the best of luck.