Assessment Of The Change Of Left Ventricular Function-Tei Index, Following The Preload Alteration By Hemodialysis

With population aging, the rate of cardiovascular disease increases year by year. How to diagnosis the abnormality of cardiac function, to evaluate the therapeutic efficacy, to judge the prognosis become more important in the clinic. The echocardiogram can show the anatomic structure, the movement of ventricular wall and the information of cardiac blood in actual time. It has the advantages of simple, accurate, safe and cheap. So it has become the main noninvasive way to measure the ventricular function.At present the echocardiogram measurement of cardiac function includes systolic and diastolic functions. The most frequently used indexes to evaluate the systolic function of left ventricular function include stroke volume (SV), cardiac output (CO), Ejection Fraction (EF) and Fractoinal Shortening (FS). In the diastolic functions, the mitral E/A ratio, isovolumic relaxation time (IRT), and E peak deceleration time (DT) are used extensively in clinic.But these indexs is effected by the display condition , the heart rate, the heart preload and afterload.Actually the abnormality of cardiac systolic functions and diastolic functions offen occur at the same time. It is more reasonable to evaluate the cardiac global function.The Japanese scholar Tei brought out a new noninvasive index for combined systolic and diastolic ventricular function in 1995. The Tei index is calculated as isovolumetric relaxation time (IRT) plus isovolumetric contraction time (ICT) divided by ejection time (ET). ICT, IRT and ET react the cardiac systolic functions or diastolic functions.But they are effected by rate, BP, cardiac load in many times. Tei indexs is the ratio of these data. Those influencing factors counteract each other. So the Tei index can evaluate the cardiac global function. It is the best index of discrimination in normal and abnormal cardiac function.The clinic value of the Tei index outweighs those traditional index, example EF, E/A, and DT .My work is about to assess the changes of left ventricular systolic and diastolic function parameters before and after a single hemodialysis session (HD). Only subjects who were in sinus rhythm, without history ofcoronary artery disease, and no evidence of cardiac valve disease and pericardial effusion were included in the study.Left ventricular Tei index, isovolumic relaxation time (IRT), isovolumic contraction time (ICT), Ejection time (ET), Ejection fraction (EF), fractional Shortening (FS), peak mitral E velocity, A velocity, E/A were calculated with HP 5500 ultrasonic system in 30 patients (male 20, female10, the mean age is 40±13, acute RF 5, GN 20). The results demonstrated that after an ultrafiltration of 2.2 1.1 liters ,peak mitral Evelocity decreased (p<0.05) and A velocity remained unchanged (p>0.05), resulting in reduction of E/A ratio (p<0.01). Left ventricular Ejection fraction (EF), fractional Shortening (FS) remained unchanged (p>0.05). The Tei index increased (p<0.01) because of significant prolongations in isovolumetric relaxation time (p<0.01) and short- ening ejection time (p<0.05). The isovolumetric contracotion time did not vary(p>0.05). The Tei index is calculated as isovolumetric relaxation time plus isovolumetric contraction time divided by ejection time. The numerator represents the left ventricular diastolic function and the denominator represents the left ventricular systolic function.Because the rate (Tei index) isn't effected relatively by those influencing factor which could effect the numerator and the demoinator, the Tei index is extensively used in estimation cardiac global function and prognosis of many Heart diseases. Many studys found that Tei index can not be influenced by the ventricular geometry, reguraitation and rate. Tei index is measured by the mitral blood flow and left ventricular outflow tract, so it is influenced by preload unavoidably.In my study the Tei index is significantly higher after an ultrafiltration, excluding the affection of rate ,history of coronary artery disease, and pericardial effusion.The Tei index was affected by hemodialysis-induced preload alterations, as well as other mitral in flow Doppler-derived parameters.When evaluating the Tei index's absolute value in a patient on maintenance HD in order to estimate global myocardial performance,one should interpret it with care, correlating it temporally with the dialysis session. But Tei index also can simply, effectively, synthetically assess left ventricular total function in HD.