Assessment Of Left Ventricular Systolic Function By Contrast Echocardiography And Continuous Wave Doppler Echocardiography And Strain Rate Imaging

Heart failure (HF) is the common end-point of various cardiovascular diseases. Individuals are typically asymptomatic in the early stage and aggravate gradually to the serious decompensated cardiac insufficiency. Because the early diagnosis and therapy can delay or prevent the onset of overt HF, it is necessary and of great importance for all the cardiovascular patients to monitor their cardiac function in time.With the improvement of ultraphonic instruments and software, new echocardiographic techniques provide effective tools for evaluation of cardiac function. In this study, contrast echocardiography and continuous wave Doppler echocardiography and strain rate imaging (SRI) were used to assess left ventricular (LV) systolic function with the aim of acquiring the early diagnosis and accurate assessment.Ejection faction (EF) is the most commonly used index to evaluate LV systolic function. In some cases, EF is not measured accurately because of the unclear image. One hundred and twelve patients, whose LV endocardial borders were not detected in at lest one segment, were injected a homely made echocardiographic contrast agent ( a suspension of perfluoropropane- filled albumin microspheres, 0.01 mg/kg). Echocardiograms were evaluated for the LV endocardial border delineation, the degree of LV opacification. EF was measured before and after contrast echocardiography. The safety of contrast agents was also observed. The score of LV endocardial border before contrast injection was (5.27 ±1.74), and it was (11.44 ±0.88) after that. Contrast echocardiography was superior to tissue harmonic imaging for EF measurement. The wall motion of 96% endocardial segments was clearly visualanalysis. The degree of LV opacification of 112 patients was 3. Vital signs, electrocardiogram, routine blood and urine test, transaminase and creatinine did not change markedly after contrast injection. This study indicateed that contrast echocardiography improve significantly LV endocardial border definition and EF measurement. The contrast agent used in this study appeared to be safe and well-tolerated to recipients.Mitral regurgitation (MR) is a common pathological phenomenon in cardiovascular disease. EF, which is calculated by LV end-systolic and end-diastolic volume, have not been proved to respond accurately to the left ventricular systolic dysfunction (LVSD) in early stage because of atrio-ventricular futile cycle. Comparing study with catheterization was to assess the accuracy and feasibility of estimation of left ventriculardp/dtmax by continuous-wave Doppler (CW) MR velocity curve. The Doppler spectrum of MR velocity of 193 patients was recorded. The velocities and time of two points on the ascending slope of the spectrum were calculated directly in order to estimate CW dp/dtmax. In 56 patients, LV dp/dtmax was measured with catheterization. The correlation coefficient between catheterization dp/dtmax and CW dp/dtmax was 0.842 (P<0.01). The regression line for the correlation between values measured by the two methods was close to one line. The results also showed a linear correlation between CW dp/dtmax and EF in 193 patients, and the correlation coefficient was 0.834 (PO.01). The correlation between CW dp/dtmax and catheterization dp/dtmax was better than that of CW dp/dtmax and EF in the subgroups divide by EF. It suggested that CW dp/dtmax should be more accurate to estimate LV systolic function and more useful to predict early LVSD than EF. This method was convenient and practical with good reproducibility, which provided a noninvasive and reliable approach to estimate LV systolic function.Strain rate imaging ( SRI) is a new technique to assess regional wall motion. Velocity vector imaging (VVI) uses a tracking algorithm to estimatemyocardial velocity at a set of points on a contour of two-dimension image independent of angle. The strain and SR of normal subjects (33 cases) and MR patients (98 cases) of septal, anterior, inferior and lateral wall in LV were evaluated and compared with EF and CW dp/dtmax in this study. The strain and SR of normal subjects were much higher than that of MR patients. The correlation between SR and CW dp/dtmax was better than that of SR and EF. It suggested that myocardial function would be assessed objectively by SR. The SR of dilated cardiomyopathy (DCM) was lower than that of the normal. There were different SR values between patients whose EF were 0.4-0.54 and the normal. The good correlation between SR and CW dp/dtmax indicated that SR should be a valuable index to detect the early LVSD.