I've had some episodes of nearly blacking out after strenuous exercise so I went to my doctor. My Aortic Bicuspid has slowly gotten narrower to the point where I am having troubles when my body demands more blood flow then can be pushed through the small valve. I'm at 0.6cm whereas a normal heart valve can open to 2.6cm. And at 86mmHc mean Gradient which is considered severe / critical range. I'm still going to get a second opinion or more accurately a second echocardiogram at a univercity hospital instead of my local towns clinic to double check the numbers but I'm fairly sure the outcome will be the same because of the symptoms. I'm just struggling with it cause I feel completely normal except for the fact of not being able to sustain a 5+ mph run for more then 1/8th a mile. I'm only 32 years old. So if I get my valve replaced I'm told and agree mechanical is the way to go for the chance I wont need reoperation ever. How Loud is it, how annoying is the noise?