Abstract 245: Real Time Three-Dimensional Diastolic Stress Echocardiography: A New Approach for Assessing Diastolic Function
Purpose: Despite symptoms during exertion, assessment of diastolic function is performed at rest. Real time 3-dimensional (3D) echocardiography is feasible during stress but its utility for assessment of diastolic function during stress has not been explored.
Methods: Full volume data was acquired at rest and peak stress in 24 patients with no ischemia on 2-dimensional stress echo. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), peak ventricular filling rate (PFR) and time to peak ventricular filling rate (TPFR) were calculated.
Results: Calculation of diastolic parameters was feasible in 100% of patients at rest and stress from full volume data sets (average acquisition time: 94 sec at rest; 65 sec at stress). Resting PFR correlated directly with EDV (r= 0.53) and SV (r= 0.66) and inversely with TPFR (r= −0.5). With stress, PFR increased by 93% and TPFR decreased by 23% (p<0.001). Stress PFR correlated with stress HR, EDV and SV (r= 0.52, 0.50 and 0.62, respectively), while TPFR inversely correlated with HR (r= −0.71). The change in PFR with stress correlated with the change in SV (r= 0.42), while the change in TPFR correlated directly with the change in diastolic blood pressure (r= 0.41) and inversely with the change in ESV (r= −0.43). Regression analysis revealed that rest and stress PFR and TPFR are independent of age, gender and BP and the change in PFR in response to stress is independent of stress HR or BP. In 8 subjects with hypertension, the change in TPFR with stress was blunted (37 vs. 29 msec, p=NS). In 19 patients in whom resting diastolic function was assessed by standard methods, E/E′ correlated directly with stress but not rest TPFR (r= 0.72) and inversely with the change in PFR and TPFR in response to stress (r= −0.67 for both). All correlation p values <0.05.
Conclusions: Assessment of diastolic function during stress is feasible using real time 3D echocardiography. This method detects the expected increase in filling rate and decrease in time to peak filling rate independent of gender, age and blood pressure. PFR at peak stress is also independent of HR. The magnitude of changes in these parameters with stress is influenced by the presence of hypertension and baseline filling pressures as measured by E/E′.