Heart complications & pregnancy?

Does anyone know of anybody who has had heart complications during pregnancy or before pregnancy. I have had aortic stenosis repair in May of 2007 and had some other problems like blood clots and went into cardiac arrest after surgery. Well, the cardiac arrest was from having a blood transfusion after losing so much blood due to bleeding internally after being on a high dose of coumadin. But anyways, my doctors said my heart and everything looks good, but i'm just so worried. I been having really bad heart palpatations and Im afraid Im going to have heart failure. I go see my cardiologist again next week. Any info would be great. And please dont be so negative. Thanks!!!