Abstract

Background. Atrial function is an integral part of cardiac function which is often neglected. The presence of left ventricular hypertrophy (LVH) due to arterial hypertension may impair atrial function. On the other hand, it has been suggested that physical training attenuates the age-associated impairment of diastolic filling. This study investigated if left atrial (LA) mechanical dysfunction is present in patients with either physiologic or pathologic LVH by use of two-dimensional Strain Rate Imaging (2DSE). Methods. Standard echocardiography, exercise stress echo and 2DSE of the left atrium were performed in 40 patients with arterial hypertension (HYP), compared with 45 age-matched master athletes (> 40 years) and with 25 healthy sedentary controls. Atrial longitudinal strain was performed from the apical views for the basal segments of LA septum and LA lateral wall, and for LA roof. Results. LV mass index and ejection fraction were comparable between patients with either physiologic or pathologic LVH. Master athletes showed increased LV end-diastolic diameter, LV end-diastolic volume and LV stroke volume, while circumferential end-systolic stress was higher in HYP. LA diameter and maximal volume were increased but similar between the two groups of patients with LVH. LA active empting volume and fraction were both higher in hypertensive patients. Conversely, peak systolic myocardial atrial strain was significantly reduced in patients with pathologic LVH compared with controls and athletes at the level of all the analyzed atrial segments (p<0.0001). By multivariable analysis, in athletes LV end-diastolic volume/BSA (beta coefficient = 0.52; p<0.0001) and LV mass (beta = 0.48; p<0.001) emerged as the only independent determinants of LA lateral wall peak systolic strain. On the other hand, in HYP an independent negative association of LA lateral wall peak systolic strain with both LV mass (beta coefficient = - 0.42; p<0.001) and circumferential end-systolic stress (beta = - 0.43; p<0.001) was evidenced. In addition, in the overall population of patients with LVH, LA lateral wall systolic strain (beta = 0.49; p<0.0001) was a powerful independent predictors of maximal workload during exercise testing. Conclusions. Two-dimensional strain represents a promising and feasible non-invasive and easy-repeatable technique to assess LA atrial myocardial function in patients with either physiologic or pathologic LVH. LA myocardial deformation is impaired in hypertensive patients compared with age-matched sedentary controls and master athletes, and is closely associated with functional capacity during effort.