This is a population-based study of the distribution of ventricular function parameters in 2,050 adult residents of Olmsted County, MN and, in collaboration with the Strong Heart study, in 1,522 adult Northern Plains American Indians. This group of Northern Plains Indians is at increased risk for LVD, having a higher prevalence of cardiovascular disease than the general United States population. Subjects undergo echocardiography to measure ventricular function parameters, as well as a clinical assessment of symptoms, signs and risk factors for LVD. Plasma concentration of n-ANP are measured in these populations to determine the accuracy of n-ANP as a noninvasive marker for asymptomatic LVD. These studies provide: comparative population-based estimates of ventricular function parameters and LVD in Olmsted County and Northern Plains Indians; estimates of the magnitude of the population of patients that could benefit from current therapy; current data on risk factors for prevalent CAD in these populations; a foundation upon which future studies of incidence and clinical course of asymptomatic LVD could be based. They also assess the accuracy of plasma n-ANP in identification of asymptomatic LVD.