Physiological relationships between central vascular haemodynamics and left ventricular structure

Left ventricular hypertrophy is an independent cardiovascular risk factor. In hypertensives, the pattern of hypertrophy is influenced by central haemo dynamic characteristics. Central haemodynamics may also determine physiolog ical differences in left ventricular structure and predispose to particular responses of the left ventricle to pathological increases in load. M-mode echocardiography was used to measure left ventricular diastolic dimension a nd to estimate left ventricular mass index, relative wall thickness and str oke volume in 159 healthy volunteers aged between 19 and 74 years. Tonometr ic sphygmography was used to estimate augmentation index, central end-systo lic and mean arterial blood pressure. Effective arterial elastance was calc ulated as the ratio of end-systolic pressure to stroke volume. Left ventric ular mass index and relative wall thickness were adjusted for variation in age, sex and blood pressure before analyses. Left ventricular diastolic dim ension exhibited significant inverse correlations with both effective arter ial elastance (r = -0.72, P < 0.0001) and augmentation index (r = -0.23, P = 0.004). Adjusted left ventricular mass index was inversely correlated wit h effective arterial elastance (r = -0.35, P < 0.0001), but no correlation was observed between left ventricular mass index and augmentation index (r = 0.04). Adjusted relative wall thickness correlated with increasing effect ive arterial elastance (r = 0.32, P < 0.0001) and augmentation index (r = 0 .18, P = 0.02), Relative wall thickness (r = 0.34, P < 0.0001), but not lef t ventricular mass index. correlated with age. Higher elastance and augment ation correlates with relatively smaller left ventricular cavity size but l arger relative wall thickness. Age-related changes in left ventricular afte rload may affect relative wall thickness more significantly than left ventr icular mass index and may contribute to a particular change in left ventric ular geometry with age.