Abstract 19660: Time-resolved Wall Stress Assessments Reveal Marked Late Systolic Load in Heart Failure with Reduced Ejection Fraction (HFREF)

Background: Systolic myocardial wall stress (MWS) quantifies myocardial afterload. MWS has historically been assessed only in end-systole, but recent time-resolved assessments in subjects with normal LV EF demonstrate that peak stress occurs in early systole, followed by a marked shift in the pressure-stress relation that reduces late systolic stress in normal hearts. This shift is dependent on progressive geometric changes during ejection. Hypothesis: HFREF is associated with an abnormal time course of LV MWS. Methods: We compared 18 subjects with HFREF (mean age=56; mean BMI=30 kg/m2; mean LV EF=34%) to controls matched for age, body size and arterial load. We assessed time-resolved LV geometry and central pressure with cardiac MRI and carotid tonometry, respectively. We computed MWS throughout ejection (Arts method). Results: Peak MWS (736 vs. 735 kdynes/cm2; P=0.99) and mean MWS throughout ejection (633 vs. 580 kdynes/cm2; P=0.38) were not significantly different between the groups. However, subjects ...