INCLUSION CRITERIA:

The subjects are adult patients in one of the following diagnostic categories: coronary heart disease or chest pain and normal coronary arteries; myocardial dysfunction or failure; hypertension; or dysautonomia. Groups of appropriately matched healthy volunteers are studied concurrently as controls.

EXCLUSION CRITERIA:

Minors are excluded.

Subjects in whom anatomic factors complicate vascular access are excluded.

Subjects who are not expected clinically to tolerate recumbency during the procedures are excluded.

Pregnant or lactating women are excluded.

Cardiology patients may be tested while off their usual medications. In this situation, the patients will be inpatients on the cardiology ward, managed clinically by staff of the Cardiology Branch, DIR, NHLBI. Hypertensives will be tested afer having discontinued anti-hypertensive medications for up to two weeks.

Patients who must take medications continually in the following categories are excluded: anticoagulants, tricyclic antidepressants, barbiturates, aspirin, acetaminophen.

Patients unable to discontinue nicotine or alcohol temporarily are excluded.