This study is designed to screen patients with heart diseases who may qualify to participate in other research studies being conducted by the Cardiology Branch of the National Heart, Lung, and Blood Institute (NHLBI).

Patients participating in this research study will be seen on an outpatient basis and undergo a general medical evaluation, including blood tests, urine, examination, chest x-ray and electrocardiogram (EKG). In addition, patients may be asked to have an echocardiogram (ultrasound scan of the heart) and to perform an exercise stress test.

Patients participating in this study will not receive any investigational treatments.

This protocol permits outpatient screening of patients with cardiovascular diseases who may be candidates for participation in current Cardiology Branch research protocols. No investigational treatments will be administered on this protocol.

Must not be enrolled in an active Cardiology Branch research protocol.

The patient must be of scientific interest to the Cardiology Branch, as determined by the investigator.

Patient is being screened for participation in an active protocol.