| ObjectiveHypertension is a familiar circulation system disease, the structure of heart is remodeled by many factors including the pressure and body fluid, and would consequentially result in abnormity of heart function, especially left ventricular diastolic function. Tei index is a new parameter that can integratively evaluate left ventricular systolic and diastolic functions with high sensitivity. This study measured the isovolumic contraction time(ICT), isovolumic relaxtion time(IRT)and ejection time(ET)of hypertension group and normal controlled group by using pulsed Doppler and Free angle M-mode echocardiography respectively. Late, Tei index and isovolumetric contraction index(ICT/ET), isovolumetric relaxation index(IRT/ET) were computed automatically by ultrasonic system. Then combined with some traditional parameters together integratively evaluate LV function of hypertension. Finally, we compared the merits, demerits and correlation of result measured respectively by using two methods, and tried inquiring a range of normal value about ICT/ET and IRT/ET.Materials and MethodsThere were 60 subjects(34 males, 26 females; age 38～79 years, 62.9±10.33 years)in normal controlled group(group C).Abnormal group included 80 patients with essential hypertension (hypertension group, Bp≥140mmHg/90mmHg, hypertension history≥one year). Case group of 80 patients were classified two groups according to left ventricular mass index(LVMI) gained by Echocardiography, group B: left ventricular myocardial no hypertrophy group, (LVMI: man<120g/m~2 , woman<115g/m~2 ), 59 patients, 34 males, 25 females, age 42～84, 64.81±9.79years; group A: left ventricular myocardial hypertrophy group, (LVMI:man≥120g/m~2 , woman≥115g/m~2 ), 21 patients, 12 males, 9 females, age 50～81 years, 66.86±8.03years.Instrument: All data were gained by using ALOKA SSD-5500 colour doppler ultrasonic system with a 2.5 MHz probe, and were saved by Medex ultrasonic imaging information system.At first we measured and noted heart rate(HR), left ventricular internal dimension at end diastole(LVIDd), the thickness of interventriculer septum(IVS) and left ventricular posterior wall (LVPW) at end diastole by conventional 2-dimension echocardiography. Then, By inputting above parameters with patient's height(m) and weight(kg), ultrasonic system computed left ventricular mass index(LVMI) automatically. Next, left ventricular ejection fraction(EF), stroke volume(SV), E/A ratio, E peak deceleration time(EDT) were assessed by using Simpson method and Pulse Doppler Echocardiography in the apical 4 chamber views. Then we measured isovolumic contraction time (ICT), isovolumic relaxation time (IRT), ejection time (ET) by using FAM and PW method. At last, left ventricular Tei index and isovolumetric contraction index(ICT/ET), isovolumetric relaxation index(IRT/ET) were computed automatically by ultrasonic system.Statistical analysis: All data were expressed as mean±SD. When compared means among many groups we adopted One-Way ANOVA test with post hoc comparison. Pearson's correlation and linear regression analyses were performed to display certain relations. All statistical analyses were performed with SPSS13.0 software. A value of P<0.05 was considered significant.ResultsThe age, sex and heart rate showed no significantly different in group C, B and A, and LVIDd, IVS, LVPW, LVMI showed significantly different in group C, B and A (P<0.05), According sequence from group C to group A Tei index gradually increased. EF was not significantly different among them. In group A and B, SV, EDT were obviously higher than group C(P<0.01), and E/A was obviously lower than group C(P<0.01); In group A E/A was obviously lower than group B(P<0.01). According sequence from group C to group A E/A gradually increased. We could obtain approving image in all accepter by using two methds. In group A and B , ICT, IRT, ET, ICT/ET, IRT/ET and Tei were obviously higher than group C were obtained by using two methds, except that ICT/ET show no significantly different between group B and C were obtained by using FAM; and then In group A all that were obviously higher than group B. In addition, between the both using two methds(FAM and PW) Tei index and related indices(ICT, IRT, ET, ICT/ET, IRT/ET) showed a close correlation. There was negative relationship between Tei index and EF, E/A, There was positive relationship between tei index and ICT, IRT, SV, EDT, LVMI; There was negative relationship between ICT/ET and ET, EF, E/A, There was positive relationship between ICT/ET and ICT, EDT, LVMI; There was negative relationship between IRT/ET and E/A, There was positive relationship between IRT/ET and ICT, IRT, ET, SV, EDT, LVMI.ConclusionsIn hypertension patients, LV integral function was damaged. LV Tei index and related parameters(ICT/ET and IRT/ET) showed a increasing trend as LVMI increase, and presented a close relation with the degree of heart failure; Tei index combined related parameters(ICT/ET and IRT/ET)could simple and integratively evaluate LV function of Hypertension with high sensitivity. There was no statistic difference between Tei index and related parameters obtained by using Free angle M-mode and pulsed Doppler echocardiography and showed a close correlation and repeatability between them. Two methods both possessed their own advantages when applied solely. Furthermore free angle M-mode echocardiography is a new and robust method to measure Tei index and related parameters.
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