Tissue Doppler Echocardiographic Study On Right Ventricular Function Of Patients With Primary Hypertension

Background and objectiveIt is known that primary hypertension can cause the structural change and functional impairment of the left ventricular(LV); some studies found that the right ventricular (RV) function also declines in hypertensive patients, however, the mechanism of RV dysfunction in primary hypertension patients was still uncertain. Some researches have demonstrated that the LV structure patterns have close relation to the motion of the LV wall; Since the LV and RV may affect each other through the interventricular septum, can the structural changes of the LV cause the RV functional decline? And more, how will the RV function evolve with the different structural changes of the LV? To explore the RV functional changes by cardiac morphology, we combined the techniques of tissue Doppler imaging (TDI) and Pulse wave Doppler (PWD) to detect the spectrum of the tricuspid annular motion, the tricuspid and pulmonary flow to analyse the evolving rules ofthe RV dysfunction in hypertensive patients with different LV patterns. We also investigated whether the remodeling of the RV and pulmonary hypertension(PH) occurred in case of the changes of the LV geometrical structure. Meanwhile we would evaluate the applying value of TDI in diagnosis of the RV function in patients with primary hypertension. MethodsEighty primary hypertensive patients, according to the left ventricular mass index (LVMI) and relative wall thickness (RWT), were divided into normal geometry group (group A, 23 cases), concentric remodeling group(group B, 22 cases) , concentric hypertrophy group (group C, 19 cases) and eccentric hypertrophy group (group D, 16 cases). Control group: 30 normal healthy volunteers. The parameters including interventricular septum thickness diastolic(IVSTd), left ventricular posterior wall thickness diastolic (LVPWTd), left ventricular end diastolic diameter (LVEDd), right ventricular end diastolic diameter (RVEDd), right ventricular anterior wall thickness diastolic(RVAWTd), tricuspid flow diastolic early peak velocity(E peak), diastolic late peak velocity(A peak), E/A ratio, right ventricular isovolumetric relaxation time(RVIRT) , right ventricular isovolumetric contraction time(RVICT) , pulmonary flowvelecity(Vp), pulmonary flow velocity time integral (Vpi) , pulmonary flow acceleration time(AT) and right ventricular ejection time(RVET) were measured with sonos-5500 echocardiograph. In TDI velocity mode, systolic peak(s peak), s peak velocity time integral(si) diastolic early peak velocity (e peak), diastolic late peak velocity (a peak) and e/a ratio were detected. Left ventricular mass index (LVMI), relative wall thickness (RWT) and right ventricular Tei index were calculated from the parameters relatively. Pulmonary systolic pressure(PASP) were estimated through the tricuspid flowregurgitant. Tei index, e peak, apeak, e/a ratio, E peak, Apeak, E/A ratio, RVIRT, speak, st, VP, VIP, AT were performed to evaluated the function of the RV. All the statistic data were showed with x + s and analyzed with SPSS 10. 0 software. Multivariate analysis of variances, analysis of variance were applied to compare the different groups. Chi-square test was applied to compare the incidence. Spearman's rank correlation and Pearson's correlation were applied to compare the relationship among or between the different parameters. Confidence interval of population rate was estimated with binomial distribution. Significant level: a =0.05. Resultsl.The diastolic pressure and systolic pressure of groupA, B, C, D were higher than control group(P all<0.01). The diastolic pressure and systolic pressure of group C, D were higher than other groups (K0. 01 or K0. 05)2. The IVSTd and LVPWTd of groups B, C and D were larger than other groups; the RWT of groups B, C was larger than other groups (.PalKO. 01); the LVMI of group C were larger than other groups (/>all<0. 01). The RVAWTd of groups C, D were larger than other groups (/>all<0. 01) ; the LVEDd and RVEDd of group D was larger than other groups (/* all<0. 01) ;3. Compared with control group, the e peak, E peak , e/a ratio and E/A ratio of groups B, C and D decreased while the RVIRT increased (P all<0. 01); the E/A ratio of groups B, C decreased (/'alKO. 01) while the a peak, A peak increased (P all<0. 01). the s peak, AT of group D decreased while Vp, Vpi increased (/> all<0. 05). The RVIRT, Tei index of groups B, C and D increased(/> all<0. 01). In groups A,B,C,D, the RVIRT and Tei index showed an increased tendency with the LV patterns changed. (RVIRT of groups A, B, C, D was 0.08s, 0. 11s, 0.13s, 0.14s. Tei index of groups A, B, C and D was 0. 31,0.45, 0. 63, 0.77. all iy=1.00, ^0.02)4. The ratio of e/a and E/A correlated each other : (in control group: r=0. 50, /<0. 01, in patients group: r=0. 42,FKO. 01); s peak and Vp possessed correlation (in control group: r=— 0. 47, K0. 01, in patients group: r=— 0. 36, K0. 01); si and Vpi possessed correlation (in control group: r=— 0. 55, K0. 01, in patients group: r=— 0. 37, K0. 05).5. In patients group, if e/a0. 05). There were no significant differences among the s peak of anterior, posterior and septal tricuspid annular(P>0. 05).7. PASP in group D was higher than control group and groups A, B an, C(/> all<0. 01).Conclusion1. Hypertension may make the RV functional change in such way: the RV function might decline with different patterns of the LV.2. In hypertensive patients, the RV function has beenimpaired before the RV remodeling; the RV remodeling has occurred before PH forms. The diastolic dysfunction of RV has occurred before the systolic dysfunction .3. TDI is effective to detect the RV function. The RV function can be evaluated by the motion of tricuspid annular. The parameters of TDI and PWD show a good correlation in the assessment of RV function. The incidence of the RV diastolic dysfunction detected by TDI is higher than that by PWD.4. The possible mode relating to the influence of the hypertension on the RV function maybe as follows: under a circumstance of a certain degree of hypertension, the left and RV remodeling form, which may lead to the RV function declining in somewhat. Only at a certain stage of the disease may the PH be involved in.