Abstract 3810: Lack of Inertia Force of Late Systolic Aortic Flow is a Cause of Left Ventricular Isolated Diastolic Dysfunction in Patients with Coronary Artery Disease
Objectives Left ventricular (LV) isolated diastolic dysfunction is a well recognized cause of heart failure. We investigated whether a lack of inertia force of late systolic aortic flow and/or apical asynergy provoke early diastolic dysfunction in patients with coronary artery disease (CAD).
Methods We evaluated LV apical wall motion and obtained LV ejection fraction by left ventriculography in 101 patients who underwent cardiac catheterization to assess CAD. We also computed the LV relaxation time constant (Tp) and the inertia force of late systolic aortic flow from the LV pressure−dP/dt relation. Using color Doppler echocardiography, the propagation velocity of LV early diastolic filling flow (Vp) was measured. In addition, using pulsed Doppler echocardiography, mitral annular velocity during systole (Sm) and that during early diastole (Em) were obtained. Patients with LV ejection fraction ≥50% (PSF, n=83) were divided into 2 subgroups: patients with inertia force (n=53) and without inertia force (n=30). No patient with systolic dysfunction (LV ejection fraction <50%) had inertia force (SDF, n=18).
Results Tp was significantly longer in patients with SDF and with PSF without inertia force than in those with PSF with inertia force (85.7±21.0, 81.1±23.6 vs 66.3±12.8 ms, p<0.001). Vp was significantly less in the former 2 groups than in the last group (27.90±4.4, 33.2±9.1 vs 47.9±9.3 cm/s, p<0.001). LV ejection fraction (70.7±59.9 vs 59.9±5.0%, p<0.001), Sm (11.6±1.8 vs 10.6±1.2 cm/s, p<0.05), and Em (12.2±2.4 vs 10.6±2.4 cm/s, p<0.005) were significantly greater in patients with PSF with inertia force than in those without. LV apical wall motion abnormality was less frequently observed in patients with inertia force than in those without (χ2=48.8, p<0.0001).
Conclusions An absence of inertia force in patients with PSF is one of the causes of isolated diastolic dysfunction in patients with CAD. Normal LV apical wall motion is crucial to give inertia to late systolic aortic flow.