Relation of age to left ventricular function and systemic hemodynamics in uncomplicated mild hypertension
Ventricular Function, Left
Previous studies in normotensive subjects have shown a slight decline in resting left ventricular pump function and midwall contractility with aging. We examined the relations of age to these variables and to peripheral resistance and vascular stiffness in 272 asymptomatic, unmedicated adults (25 to 80 years old) who had uncomplicated essential hypertension. Cardiac and carotid ultrasound and carotid pressure waveforms were obtained to measure left ventricular dimensions, endocardial and midwall left ventricular shortening, stroke index and cardiac index, end-systolic stress, and pulse pressure/stroke index and beta, pressure-dependent and independent measures of vascular stiffness, respectively. Endocardial and midwall stress-corrected left ventricular shortening assessed ventricular performance. Cardiac index and TPRI did not change with age in either gender, with age-related increases in systolic pressure offset by increasingly concentric ventricular geometry in women and enhanced ventricular systolic function in men. In contrast to the lack of age-related change in traditional hemodynamic indexes, pulse pressure/stroke volume and beta strongly increased with age (P<0.001). Thus, in uncomplicated, relatively mild essential hypertension, neither cardiac index nor peripheral resistance is associated with age. This hemodynamic stability is associated with age-related increased concentricity of ventricular geometry in women and increased ventricular performance indexes in hypertensive men. Vascular stiffness progressively increases with age, independent of change in mean pressure or resistance, possibly contributing to increased rates of cardiovascular events in older individuals.