Relation of hemodynamic volume load to arterial and cardiac size

Abstract

Objectives. This study sought to assess the relation of Doppler stroke volume (SV) to cardiac and carotid artery size and to determine whether volume load accounts for the parallelism between the two. Background. It has been suggested that altered hemodynamic volume load can modify the degree and pattern of left ventricular (LV) hypertrophy from that predicted from blood pressure (BP) alone. Methods. We related Doppler echocardiographic SV in 342 normotensive or unmedicated asymptomatic hypertensive adults to echocardiographic LV mass, LV internal dimension (LVID), wall thickness, carotid ultrasound arterial lumen diameter, intimal-medial thickness (IMT) and cross-sectional area (CSA). Results. SV was positively related to LV mass (r = 0.42), LVID (r = 0.45), ventricular wall thickness (r = 0.20 to 0.29) and carotid diameter (r = 0.23, all p < 0.0001); CSA (r = 0.17, p < 0.002); and IMT (r = 0.12, p = 0.03). In multivariate analyses controlling for awake ambulatory BP and the circumferential end-systolic stress/end-systolic volume index ratio, SV remained an independent predictor of LV mass and chamber size (both p < 0.0001) but not LV wall thickness. SV also predicted carotid diameter (p < 0.0002), CSA (p = 0.001) and, to a lesser degree, IMT (p = 0.02) after controlling for mean awake BP and age. In additional analyses, LV and carotid dimensions were significantly interrelated independent of SV. Conclusions. SV measured by invasively validated Doppler echocardiography is associated with LV and carotid artery enlargement and eccentric hypertrophy, independent of arterial pressure, LV contractility, age and body size; however, SV and other variables do not account for the previously documented parallelism between cardiac and arterial structure.