To Assess The Short-term Effects Of Cardiac Resynchronization Therapy By Contrast Echocardiography

Objective:Cardiac resynchronization therapy（CRT）can reduce heart failure symptoms,improve LVEF,and reduce mortality through biventricular pacing.This study intends to measure left ventricular volume and LVEF_Simpsonby contrast echocardiography to better assist the clinic to screen out the patients with heart failure before CRT and assess the short-term effects of cardiac resynchronization therapy.Methods:Screen out 17 patients with heart failure Before cardiac resynchronization therapy implantation.firstly,measure the left atrial end systolic diameter（LAESD）,the inter-ventricular septal end diastolic thickness（IVSD）,the left ventricular diastolic posterior wall thickness（LVDPWT）,the left ventricular end diastolic diameter（LVEDD）,the left ventricular end systolic diameter（LVESD）and the left ventricular ejection fraction(LVEF_Teich)by the M-mode Echocardiography.Secondly,measure the left ventricular end systolic volume(LVESV_Simpson),the left ventricular end diastolic volume(LVEDV_Simpson)and the LVEF_Simpsonby the conventional two-dimensional echocardiography biplane summation-of-disks method.Thirdly,measure the LVESV_Simpson,the LVEDV_Simpsonimpson and the LVEF_Simpsonby contrast echocardiography biplane summation-of-disks method.Half a year after the cardiac resynchronization therapy,remeasure these data by the M-mode echocardiography,the conventional two-dimensional echocardiography and the contrast echocardiography.Then compare the preoperative and postoperative data with the relevant ultrasound parameters.Lastly,according to the guidelines,the CRT will be proven to work if the LVESV decreases over 15.0%.Results:The all patients included in this study were symptomatic heart failure with LVEF<35.0%.The results showed that only 35.3%of patients had LVEF<35.0%measured by the M-mode echocardiography and only 70.6%of patients had LVEF<35.0% measured by the conventional two-dimensional echocardiography biplane summation-of-disks method.But 100%of patients had LVEF<35.0%measured bycontrast echocardiography biplane summation-of-disks method.The effective rate of CRT obtained by the conventional two-dimensional echocardiography biplane summation-of-disks method（47.1%）is higher than that obtained by the M-mode echocardiography（11.8%）.The effective rate of CRT obtained by contrast echocardiography biplane summation-of-disks method（82.4%）is higher than that obtained by the M-mode echocardiography（11.8%）,and also higher than that obtained by the conventional two-dimensional echocardiography biplane summation-of-disks method（47.1%）.The differences are statistically significant（P<0.05）.Among the 17 patients,there are 14 patients detected that the NYHA functional class is reduced at least one level,compared with before CRT.And 3 patients are detected that the NYHA functional class changes little compared with before CRT.It is consistent with the conclusions whose LVESV_Simpsondata is obtained by contrast echocardiography.Conclusions:1.contrast echocardiography can improve the accuracy of left ventricular volume and LVEF measurement.2.contrast echocardiography can better assist the clinic to screen out the patients with heart failure before CRT and assess the short-term efficacy of cardiac resynchronization therapy.