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 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). BACKGROUND Left ventricular (LV) isolated diastolic dysfunction is a well-recognized cause of heart failure. METHODS We evaluated LV apical wall motion and obtained left ventricular ejection fraction (LVEF) 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 (P)-first derivative of left ventricular pressure (dP/dt) relation. Using color Doppler echocardiography, we measured the propagation velocity of LV early diastolic filling flow (Vp). Patients with LVEF > or =50% (preserved systolic function [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 (SDF) (LVEF <50%) had inertia force (n = 18). RESULTS The Tp was significantly longer in patients with SDF (85.7 +/- 21.0 ms) and with PSF without inertia force (81.1 +/- 23.6 ms) than in those with PSF with inertia force (66.3 +/- 12.8 ms) (p< 0.001). The Vp was significantly less in the former 2 groups than in the last group. In patients with PSF, LV apical wall motion abnormality was less frequently observed in those with inertia force than in those without (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 substantial enough to give inertia to late systolic aortic flow.