Echocardiography (TTE and TEE) is much better in evaluating cardiac valves when compared to cardiac catheterization. The catheterization does not evalute the mitral valve well, and it doesn't even look at the tricuspid valve. All that can be well assessed from cardiac catheterization is the LV function (EF) and the coronary arteries. Keep in mind that a normal EF in someone with severe mitral regurgitation may already be a sign of needing surgery as a heart with a normal EF and a leaky mitral valve isn't really normal any more. When someone has a leaky valve their ejection fraction should be super normal, because a lot of blood is leaking back to the atrium and not going to the aorta. The fact that you are having lots of exertional shortness of breath is also a sign for surgery. The stress test that your other doctor wants to order is not completely unnecessary. In some situations, it is not easy to assess someone's symptoms and correlate them with a specific condition. When one performs a stress echocardiography, they can get objective evidence of what happens to the valve and the pulmonary pressures during exertion. Again, it is not a necessary test in your sistuation, but your doctor wants to be 100% sure that surgery is indicated.
I 'm a 38yrs having almost the same signs &symptoms. My Dr said my EF=50% to 55%. I am very nervous.