No. Its usually not 'sudden'. Its usually pre-existing heart disease that wasnt caught ahead of time.
It doesn't. Where did you hear this?
What happens if there is heart failure and breathing difficulty present when resting, does it get worse when exercising or better instead?
Worse. Shortness of breath at rest in a patient with heart failure indicate advance stage of heart failure. Any extra physical work is usually not well tolerated and will make breathing worse. It is best to make patient comfortable of whatever means such as position, and adjustment of medications to control fluids.
Scared I may have heart failure. I'm 30, in good shape, eat healthy and workout. But have been feeling run down, nauseous, and fast heart beat?
Pretty unlikely. The symptoms of heart failure also include, leg swelling and shortness of breath when lying down. There are also several things you doctor can look for on physical exam... I would see your doctor about your symptoms, but I doubt it's heart failure.
If I had heart failure and artery blockage would I still be able to get through a workout without angina and pain I am dizzy light headed though?
Yes you could. You should be under the watchful eye of a good cardiologist who is making recommendations about what is and is not safe exercise for you. Anyone who is 31 with a history of CHF and CAD should be carefully educated about their disease and already know the answer to this question. Follow up with your cardiologist.