| Objective: To assess the impact of RV contractility on LV function anddyssynchrony by Echocardiography.Methods:54patients with RV dysfunction or with remote cause of RVdysfunction by echocardiography (25males,29females, mean age64.6±15.6years).32cases had RV dysfunction, as defined by a tricuspid annulus systolic displacement(TAPSE)<16mm, according to the guidelines for the echocardiographic assessment ofthe right heart from the American Society of Echocardiography (ASE), while theremaining22cases had normal right ventricular function with TAPSE≥16mm; and26cases of healthy volunteers (male17, female9, age range15±84years)were selectedas control group. All participants underwent a transthoracic echocardiographic studyincluding two-dimensional, color flow and pulse wave Tissue Doppler as well astissue velocity imaging using a GE Vivid7.0ultrasound system(GE vivid7.0). AnECG was simultaneously recorded and the images and the data of the test were stored.From parasternal long axis view, with conventional two-dimensionalechocardiography, end-diastolic diameter of right ventricular (RVEDD), end-diastolicdiameter of left ventricular (LVEDD), and end-diastolic thickness of interventricularseptal (IVSd) were measured. From the apical4-champer view, mitral flow velocitypattern was recorded with the doppler sample volume placed at the tips of the mitralleaflets, and left ventricular ejection fraction (LVEF), right ventricular end-diastolicareas (RVEDA) and end-systolic areas (RVESA) were measured. The rightventricular fractional area change (RVFAC) was calculated by the following formula:RVFAC=(RVEDA-RVESA)/RVEDA. With pulse wave Tissue Doppler Imaging,the systolic (Sm), early (Em) and late (Am) diastolic annular velocities were measuredat the left ventricular lateral wall (LVW), interventricular septum (IVS) and right ventricular lateral wall (RVW) from the apical four-chamber view. Region of interestwas placed at LVW to measure isovolumic contraction time (IVCT), isovolumicrelaxation time (IVRT) and ejection time (ET). Myocardial performance index (Tei)was calculated by the following formula: Tei=IVCT+IVRT/ET. With Tissue VelocityImaging (TVI), regions of interest were palced at left ventricular lateral wall (LVW)and interventricular septum (IVS) to measure the time-to-peak (TTP) of systolicvelocity from the onset of Q-wave on the electrocardiogram to calculate timedifference between LVW and IVS.Results：1. Compared with control group, the following parameters in normal RVfunction and RV dysfunction group increased significantly respectively: RVEDD(16.5±1.1mm vs19.2±3.2mm vs22.9±3.0mm, P<0.01), IVSd (8.7±1.0mm vs9.4±1.2mm vs10.1±1.2mm, P<0.01or P<0.05); LVEDD decreased significantly onlyin RV dysfunction group (44.6±3.2mm vs37.1±4.8mm, P<0.01). Compared withnormal RV function group, RVEDD and IVSd increased, and LVEDD decreased inRV dysfunction group (P<0.05or P<0.01).2. Compared with control group, E wave, E/A ratio in RV dysfunction group werelower (P<0.05); Compared with normal RV function group, only E wave was lower inRV dysfunction group.3. Compared with control group, RVFAC decreased significantly (P<0.01);Compared with normal RV function group, RVFAC also decreased significantly(P<0.01).4. Compared with control group, the following parameters in normal RV functiongroup decreased or increased significantly respectively: the Em, Em/Am, E/Em of LVW(P<0.05or P<0.01); the following parameters in RV dysfunction group decreased orincreased significantly respectively: Sm, Em, Em/Am, E/Em of LVW. Compared withcontrol group, Sm of RVW in normal RV function and RV dysfunction group werelower significantly; Compared with normal RV function group, Sm of RVW in RVdysfunction group were lower (P<0.01).5. Compared with control group, Tei index of LVW in normal RV function andRV dysfunction group increased significantly (0.49±0.2vs0.7±0.2vs0.9±0.2，P<0.01).6. Compared with control group, the TTP of LVW at the annulus in normal RVfunction and RV dysfunction group delayed significantly (P<0.05); Compared withcontrol group, the time difference of mechanical activation between LVW and IVS in normal RV function and RV dysfunction group increased significantly respectively(7.2±6.6ms vs15.1±12.7ms, P<0.05；7.2±6.6ms vs19.7±15.6ms，P<0.01).7. Compared with normal RV function group, the TTP of LVW at the annulus inRV dysfunction group delayed (137.7±22.9ms:139.6±23.7ms，P=0.756); the timedifference of mechanical activation between LVW and IVS in RV dysfunction groupincreased (15.1±12.7ms vs19.7±15.6ms, P=0.194)Conlusion: Right ventricular function was associated with left ventricular (LV)function and intra-LV dyssynchrony by the ventricular interaction: The changes of leftventricular structural were found in some patients with RV dysfunction. Patients withRV dysfunction had left ventricular diastolic and systolic dysfunction, and diastolicfunction abnormalities occurred earlier than systolic dysfunction. And rightventricular function was related with intra-LV dyssynchrony. Tei index was a simpleand sensitive index to estimate LV dysfunction. |
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