Cardiovascular Disease Screening

This study will evaluate volunteers 18 years of age and older to see if they qualify for one of NHLBI s research studies. Tests include the following: * General medical evaluation, which may include blood tests, chest x-ray, electrocardiogram (ECG) and echocardiogram (heart ultrasound). * Other tests as appropriate, such as magnetic resonance imaging (MRI), cardiac computed tomography (CT scan of the heart), nuclear stress test and echocardiography stress test. * X-ray contrast studies of the heart and blood vessels. (These may be excluded in patients with kidney risk factors.)