The Clinical Study Of Wave Intensity Technique In Assessing Systolic Function Of Left Ventricle

Part One Studying normal left ventricular function by Wave intensity analysisObjective: To investigate the left ventricular function in normal people by using a Wave Intensity (WI) analysis. To explore the clinical application value of this new technique by studying the variation of WI indices among different age and gender.Methods: Group all 156 healthy volunteers by age and gender. Use ALOKAα10 ultrasonic diagnosis system with WI analysis software. Assess WI indices including W1, W2, NA, R-W1, W1-W2. Regular echocardiography was used in measuring diameters of left ventricular, and LVEF was calculated by Simpson's way. Then compare all WI indices among the groups of age and gender. The relationship between age and WI indices was also investigated.Results: No significance was seen in difference of WI indices among the age groups and between sexes. And there was no obvious relationship between WI indices and age.Conclusion: The assessment of WI by the noninvasive way of Ultrasonic technique is available in healthy people by advantage of its convenience and inexpensiveness. But there should be more investigation in reference values before its application in widely clinical use.Part Two Clinical study of wave intensity in assessing left ventricular function of patients with chronic heart failureObjective: To investigate the clinical application of Wave Intensity (WI) technique in assessing the systolic function of left ventricle in patients with Chronic Heart Failure (CHF).Methods: 94 CHF patients and 127 healthy volunteers were enrolled in the study. All CHF patients were divided into 3 groups by classification of NYHAⅡ~Ⅳ. The magnitude of W1, and the length of R-W1 interval as well as W1-W2 interval were recorded by WI technique. Left Ventricular diameters and volumes in end systole and in end diastole were measured in 2D Echocardiography, then calculated left ventricular ejection fraction (LVEF). By pulsed wave tissue Doppler, the peak velocity of mitral annulus at systolic phase (Sm) was measured. Those parameters of left ventricular systolic function of all subjects were studied to observe the differences existed in the 4 groups, and to investigate the relationship between the WI indices and regular Echocardiographic parameters.Results: Compared to the control group, W1 and W1-W2 interval were significantly shorter in CHF groups, while R-W1 interval was longer (P<0.01). Among all CHF groups, patients of NYHAⅢ~Ⅳhave lower W1 than those of NYHA ClassⅡ. The amplitude of W1 were closely related to LVEF and Sm in CHF group (r1=0.62, P<0.01; r2=0.48, P<0.01).Conclusion: As a novel hemodynamic index which could evaluating the integral behavior of cardiovascular system, WI provides a potential exploration in conveniently and effectively assessing the LV systolic function of CHF patients.Part Three Clinical study of wave intensity in assessing short-term effects of cardiac resynchronization therapyObjective: To investigate the clinical application of wave intensity (WI) technique in assessing the short-term effects of cardiac resynchronization therapy (CRT).Methods: 16 patients with congestive heart failure treated with CRT were chosen. Before the implantation of CRT pacemaker and 1 week/1 month/3month after it, the diameters and volumes of left ventricular in the end-diastole and the end-systole were measured by echocardiography. Ejection fractions (LVEF) were calculated by Simpson's way, and the variation ratio of left ventricular end-systolic volume (ΔESV) was assessed each time after the CRT. The maximal rate of left ventricular pressure rise (LVdP/dtmax) was assessed in the continuous-wave Doppler spectrum of mitral regurgitation. The magnitude of W1, and the length of R-W1 interval as well as W1-W2 interval were recorded by WI technique applied on the left carotid artery of each patient.Results: Compared to the data before CRT, W1 and W1-W2 interval were significantly higher in different period after CRT (P<0.01). This result was conform with regular Echocardiographic data and other indices of LV systolic function.Conclusion: As a novel hemodynamic index which could evaluating the integral behavior of cardiovascular system, WI provides a potential exploration in conveniently and effectively assessing the CRT effects in short-term.