Association of left atrial phasic volumes with systemic arterial stiffness and ankle-brachial index in hypertensive patients
Left atrial (LA) phasic volumes consist of reservoir, conduit and booster pump volumes. Arterial stiffness is linked to lower systemic arterial compliance (SAC) contributing to cardiac afterload. Arterial stiffness may be a modulator of LA phasic volumes. Echocardiography was performed in 161 hypertensive patients and in 50 normotensive subjects in order to assess biplane LA volumes (maximum, before atrial contraction, minimum), early and late diastolic mitral annular velocity (e′ and a′), and LV stroke volume. LA emptying volumes (total, passive, active) were calculated from these LA volumes. Blood pressures were measured using an automated oscillometric device simultaneously at the four limbs for evaluating pulse pressure (PP) and ankle-brachial index (ABI). SAC was estimated by the ratio of LV stroke volume indexed by body surface area (BSA) divided by PP. All three LA volumes, LA total volume and LA active emptying volume were greater in hypertensive patients than in normotensive subjects. A multiple linear regression analysis indicated that LA passive emptying volume (reservoir = early diastole)/BSA correlated positively with ABI after being adjusted for age, gender, BSA, LV mass, max LA volume, e′ and SAC in hypertensive patients. LA active emptying volume (booster = late diastole)/BSA correlated positively with SAC after being adjusted for age, gender, BSA, LV mass, LA volume before atrial contraction, a′ and ABI. LA reservoir volume was associated with ABI, and LA booster volume was related to systemic arterial stiffness in hypertensive patients, suggesting the LA-arterial coupling in this clinical setting.