Abstract 15695: Late Systolic Myocardial Loading is Strongly Related to Left Atrial Dysfunction in Hypertension

Background: Late systolic load has been shown to cause diastolic dysfunction in animal models. Whereas the systolic loading sequence of the left ventricular myocardium likely affects its coupling with the left atrium, this issue has not been investigated in humans. Methods: We studied 218 subjects with hypertension. Atrial mechanics were measured with cine SSFP MRI, from the 4-chamber and 2-chamber views, using tissue tracking (CVI42; Circle CV Imaging; Calgary, Canada). algorithm. The central systolic arterial pressure profile was assessed with carotid tonometry. Time-varying ejection-phase wall myocardial wall stress (MWS) was assessed with the Arts formula. The MWS time-integral (area under the MWS curve) in the 1st half of ejection (early systolic) and the 2nd half of ejection (late systolic) were computed. Results: Late systolic load was strongly associated with poor LA conduit and reservoir function, whereas early systolic load was associated with better LA function, indicating an effect of the rela...