Assessment Of Left Ventricular Regional Systolic Function Of Patients With Different Graded Coronary Artery Stenosis By Three-dimension Speckle Tracking

Background and ObjectiveThree-dimension speckle tracking imaging (3D-STI) is a new ultrasound technology which be used to assessment the truly three-dimension movement of myocardium,3D-STI can evaluation the regional and global ventricular function by tracking the three-dimension movement of the ultrasonic speckle patterns in myocardium, It is independently of angle,and the global movement of myocardium can't impact the tracking. Although 3D-STI is just used in clinic, the accuracy and reliability has been proved by many foundational and clinical experiments. And it is capable of displaying results of the entire myocardium using a single databaset, so can assess the time of myocardium movement better. Coronary atherosclerosis can induce different extent of coronary artery stenosis (CAS), the function of the myocardium has been impacted, but there are less research about the fact of different CAS to regional ventricular function. People had discovered there is a good correlation between ventricular dyssynchrony and the change of ventricular function, the prognosis of disease.Although the major research about ventricular dyssynchrony of CAD focus on the patients with myocardium infarction.the studies about patients who with different CAS are less. We will assess the alterations of the regional systolic peak strain in ischemic myocardial segments and the change of movement time in patients with different extent of coronary artery stenosis using 3D-STI, investigate the application and provide a new technique of 3D-STI in diagnosis of CAD.Materials and Methods97 CAD patients who been initially diagnosed were selected, with 53 men,44 women, aging from 35 to 70, Exclude standard:Acute and chronic myocardium infarction; cardia valve disease; cardiomyopathies; chronic obstructive pulmony disease; myocardial hypertrophy; severely cardiac arrhythmia, moderate and severe hypertension.All patients were examed by selected coronary angiography (SCA), every left ventricular segment of all patients were divided into 5 groups according to coronary stenosis based on the results of SCA:normal,≤25%, (25%,50%], (50%,75%],>75%. and all patients were divided into 5 groups according to the max coronary stenosis extent:normal, stenosis extent≤25%; stenosis extent (25%,50%]; stenosis extent (50%,75%],; stenosis extent>75%. Recorded the general information of patients, and received the conventional echocardiography exam, collected the 3D-STI imaging, then analyzed.3D-STI measurement indicators included:each peak radial strain and area strain of all segments of left ventricular (RS, AS); the time to peak radial strain and area strain (T-RS, T-AS); the standard deviation of the time to peak radial strain of 16 standard myocardial segments (Tsrs-SD); the max difference of time to peak radial strain of 16 standard myocardial segments (Tsrs-Diff); the standard deviation of time to peak area strain of 16 standard myocardial segments (Tsas-SD); the max difference of time to peak area strain of 16 standard myocardial segments (Tsas-Diff).Results1. In the coronary normal and stenosis extent≤25% group, the RS, AS wave distributed regularly, RS wave was negative, and AS wave was positive, the variance was non-significant; the partial waves of coronary stenosis extent (25%,50%], (50%,75%],>75% groups were derangemental, some peak of waves were palinal, even conversed. Compared with the group of coronary normal and stenosis extent≤25%, the absolute values of RS,AS decreased in groups of coronary stenosis (25%,50%], (50%,75%],>75%, compared with the group of coronary stenosis extent (25%,50%], the absolute values of RS, AS decreased in groups of coronary stenosis (50%,75%],>75%, compared with the group of coronary stenosis extent (50%,75%] the absolute values of RS, AS decreased in groups of coronary stenosis >75%, some variance was significant.2. The variance of T-RS,T-AS between group of coronary normal and stenosis extent≤25% was non-significant.Compared with the group of coronary normal and stenosis extent≤25%, T-RS, T-AS increased in groups of coronary stenosis (25%,50%], (50%,75%],>75%, compared with the group of coronary stenosis extent (25%,50%], T-RS, T-AS increased in groups of coronary stenosis (50%,75%],>75%, compared with the group of coronary stenosis extent (50%,75%], T-RS, T-AS decreased in groups of coronary stenosis >75%, some variance was significant.3. The variance of Tsrs-SD, Tsrs-Diff, Tsas-SD, Tsas-Diff between group of coronary normal and stenosis extent≤25% was non-significant.Compared with the group of max coronary normal and stenosis extent≤25%, Tsrs-SD, Tsrs-Diff, Tsas-SD, Tsas-Diff increased in groups of max coronary stenosis (25%,50%], (50%,75%],>75%, the variance of groups of max coronary stenosis (50%,75%],>75% was significant. Compared with the group of max coronary stenosis extent (25%,50%], Tsrs-SD, Tsrs-Diff in groups of max coronary stenosis (50%,75%]and Tsrs-SD, Tsrs-Diff, Tsas-SD, Tsas-Diff in groups of max coronary stenosis >75% increased, the variance was significant. Compared with the group of max coronary stenosis extent (50%,75%], Tsrs-SD, Tsrs-Diff, Tsas-Diff in groups of max coronary stenosis >75% increased, and the variance was significant. Conclusion1. In resting-state,3D-STI can quantitatively check the abnormal regional function of left ventricular when the homologous coronary artery is severe.2. Along with the coronary stenosis increase, the regional function of left ventricular have impaired:RS, AS decrease gradually, T-RS, T-AS increase, and left ventricular dyssynchrony occur.3. The time of peak strain will increase along with the coronary stenosis increase, but the tendency exist that the time of peak strain will decrease when the coronary stenosis is more than 75%,compared with the coronary stenosis (50%,75%]. Maybe this is the result of the myocardium function further impared.