The Relationship Between Left Ventricular Long-axis Systolic Function And Integrated Backscatter In Patients With Rheumatic Mitral Stenosis

[Abstract] Objective To detect the alteration of integrated backscatter and left ventricular (LV) long-axis systolic function in patients with isolated rheumatic stenosis (MS) and investigate the relationship and its clinical significance. Methods Parasternal long-axis view of LV was obtained in left lateral decubitus position. Average image intensity (AII) and cyclic variation in IBS (CVIB) on the basal septum, posterior wall and pericardium were mearsured after the IBS was actived in 54 patients with isolated MS and 35 healthy volunteers. Calibrated IBS (IBS%) was obtained by subtracting pericardial IBS from one of the septum or posterior wall. Using tissue Doppler imaging, the mitral annular systolic velocity (S_M), the systolic excursion (D_S), the pre-contraction time (PCT_M), contraction time (CT_M) and PCT_M/CT_m ratio were measured. Results According left ventricular ejection fraction (EF), 54 patients with MS were further divided into two subgroups, i. e. normal EF group containing 42 patients with EF of more than 50% and decreased EF group containing 12 patients with EF of less than 50%. IBS% in patients with either of normal EF or decreased EF was significantly greater than in controls (P<0.001), and in patients with decreased EF was greater than in patients with normal EF (P<0.001). CVIB in patients with either of normal EF or decreased EF was significantly lower than in controls (P<0.001), and in patients with decreased EF was lower than in patients with normal EF (P<0.001). Sm in patients with either of normal EF or decreased EF was significantly lower than in controls (P<0.001),and in patients with decreased EF was lower than in patients with normal EF (P<0.01). Ds in patients with either of normal EF or decreased EF was significantly lower than in controls (P<0.01, P<0.001), and in patients with decreased EF was lower than in patients with normal EF (P<0.001). PCT_m/CT_M ratio in patients with either of normal EF or decreased EF was significantly greater than in controls (P<0.01, P<0.001), and in patients with decreased EF was greater than in patients with normal EF (P<0.001). The incidences of long-axis systolic dysfunction in MS patients with normal EF and those with decreased EF were respectively 60.2% and 100%. S_M, D_S, PCT_m/CT_m ratio,IBS% and CVIB correlated with mitral effective orifice area in patients with MS (r=0.52, P<0.001;r=0.34, P<0.05;r=-0.43, P<0.01;r=-0.44, P<0.01;r=0.46, /k0.001 , respectively). S_M, D_S, PCTJCT_M ratio, IBS% and CVIB correlated with MPG (r=-0.54, P<0.001;r=-0.32, P<0.05;r=0.32, P<0.05;r=0.54, P<0.001;r=-0.50, P<0.001, respectively). LVEF correlated with S_M, D_S, PCT_M/CT_M ratio, IBS% and CVIB (r=0.61, P<0.001;r=0.50, P<0.001;r=-0.42, /><0.001;r=-0.71, /kO.OOl;r=0.53, /kO.OOl, respectively). SM correlated well with CVIB (r=0.82, ZkO.OOl), and IBS% (r=-0.62,/><0.001). Ds correlated moderately with IBS% and CVIB (r=-0.63, /kO.OOl;r=0.61, P<0.001). ?CTJCTM ratio correlated with IBS% and CVIB (r=0.40, /kO.OOl;r=-0.47, /kO.OOl). Conclusions Left ventricular exists myocardial fibrosis in the majority of patients with MS, and left ventricular dysfunction correlated with myocardial fibrosis. Left ventricular long-axis systolic dysfunction exists in the majority of patients with MS, and it occurs before left ventricular short-axis dysfunction. IBS and TDI techniques not only can detect the structural and functional changes of isolated MS sensitively and quantitatively, but they show good concord agreement, which shows the two techniques for discovering isolated MS liablely, invasively and safely, and offer a new way to select the surgery opportunity.Postgraduate student: Meixin Liu (Echocardiography) Directed by Prof. Zhibin Wang...