Preliminary Study On Myocardium Infaction Assessment In Canine By Speckle Tracking Imaging With Intracardiac Echocardiography

Objective: Intracardiac echocardiography (ICE) could provide high qualified ultrasound image and speckle tracking imaging assessment was known as angular independent technique, however, there are little reports for the intersection field. We assumed that it will be more appropriate for myocardium infarction assessment. Thus provide preliminary study for percutaneous endocardium gene transfer (PEGT) in future.Methods: On the ground of National Nature Science foundation(key project), we developed a new multifunctional ICE with ShanTou Institute of Ultrasounic Instruments which is a longitudinal side-fire transducer (6.5-10MHz), with a 7F diameter, 32 phased vector array, M-type,B-type ultrasound imaging and transendocardium ejection function. Transthoracic echocardiography was recorded by another probe to compare the image quality. To investigate the feasibility of combination between STI and ICE, acute myocardium infarction model (AMI) was established by the ligation of left anterior descending coronary artery (LAD) in canine for 2 hours, and ICE was inserted into left ventricular chamber from apical simultaneously. Echocardiography of anterior myocardium was recorded on 0min and 120min, which was divided into Control and AMI group, respectively. Myocardium radial strain on 2D echocardiography was analyzed by self-program STI software and quantitative movement of myocardium was extracted from M type Ultrasound with our own method. Linear regression and correlation was introduced to analyze the relationship between peak radial strain and max movement of myocardium in different points.Results:1,This self-design and development multifunction ICE had much less size in diameter (about 2.3mm) and provided more clear ultrasound image than transthoracic one.2,Along with myocardium infarction, Radial strain in baseline was significant different from that in 120min in which peak radial strain decreased from 33.2±4.3% to 9.2±2.1% (P<0.01).3,Along with myocardium infarction, Movement in baseline was significant less than that in 120min in which the max movement decreased from 0.58±0.08cm to 0.13±0.03cm (P<0.01).4,Myocardium peak radial strain and movement correlated well with each other (r=0.9968). Conclusions:1,This independent design and development multifunctional ICE had much less size in diameter than previous one (about 2.3mm) which meet the strict criterion for interventional cardiac catheter, thus reduced intervention risk and operation complication. In addition, this homemade multifunctional ICE will no doubt release the economic burden of patient thus provide more services for clinic.2,ICE could provide more clear ultrasound image than transthocic one which offered a credible platform for STI assessment.3,On the ICE imaging basis, myocardium infarction was successfully investigated by self-program STI software with radial strain analysis in which peak radial strain correlated well with max movement. Thus validate the feasibility and provide preliminary study for PEGT in future.