RNA has clinical applications in virtually all forms of acquired heart disease and is also useful in the detection and quantitation of congenital left-to-right shunts. The method has achieved widespread acceptance for the qualitative and quantitative assessment of systolic ventricular function. It is also particularly well suited for identifying abnormal diastolic filling patterns typical of hypertrophic and ischemic heart diseases. To date, no single variable from any noninvasive or invasive procedure has been shown to have greater prognostic importance than the radionuclide exercise ejection fraction in patients with CAD.