Evaluation Of Left Ventricular Global And Regional Systolic Function In Patients With Different Graded Coronary Artery Stenosis By Three-dimensional Speckle Tracking Imaging

Part one Evaluation of left ventricular global systolic functionin patients with different graded coronary artery stenosis bythree-dimensional speckle tracking imagingObjective: To evaluate left ventricular global systolic function by usingthree-dimensional speckle tracking imaging (3D-STI) in patients withdifferent graded of coronary artery stenosis, and to determine the clinicalvalue in diagnosis of different graded coronary artery stenosis.Methods: Seventy-nine patients were selected between November2012and November2013. All subjects without left ventricular segmental wallmotion abnormality. According to the coronary stenosis based on the resultsof coronary artery angiography (CAG). They were divided into four groups,there were23cases in normal group (coronary artery has no stenosis),16cases in mild stenosis group (stenosis rate<50%),21cases in moderatestenosis group (stenosis rate50%～75%) and19cases in severe stenosisgroup (stenosis rate≥75%). Collecting full-volume image of apicalfour-chamber, the software was applied to acquire the data including thesystolic peak global area strain (GAS), the systolic peak globalcircumferential strain (GCS), the systolic peak global longitudinal strain (GLS)and the systolic peak global radial strain (GRS). The global strains todiagnose different coronary artery stenosis were analyzed under the receiveroperating characteristic (ROC) curve.Results: Compared with the normal group, the severe stenosis group hadlower GAS,GCS,GLS and GRS (P＜0.05); the moderate stenosis group hadlower GAS and GLS (P＜0.05). ROC curve shows that along with the coronary stenosis increase, the area under the ROC curve (AUC) of eachstrain increase. The AUC of GAS to diagnose severe stenosis was0.840, thecutoff value, the sensitivity and specificity were-28.25%,68.4%and91.3%,respectively.Conclusions: The longitudinal, circumferential and radial systolicfunction have damaged in patients with the moderate and severe stenosis, thesevere stenosis group was impaired significantly. GAS has the highestaccuracy to diagnose severe stenosis among the four global strain parameters.3D-STI can early show the changes of left ventricular global systolic functionin patients with CHD. Part two Assessment of left ventricular ischemic segmentalstrain in coronary heart disease by three-dimensional speckletracking imagingObjective: To analyze left ventricular regional strain in ischemicmyocardium of coronary heart disease (CHD) by using three-dimensionalspeckle tracking imaging (3D-STI) and to evaluate the value of3D-STI indiagnosing CHD with receiver operating characteristic (ROC).Methods: Thirty-nine control subjects (stenosis rate<50%) and fortypatients with CHD (stenosis rate≥50%) confirmed with coronary arteryangiography were involved. All of them were not found left ventricularsegment wall motion abnormality by conventional echocardiography. TheCHD group included15cases in single vessel lesion [12cases of left anterior descending (LAD),2cases of left circumflex (LCX) and1case of rightcoronary artery (RCA)];13cases in double vessel lesion (4cases of LADcombined LCX,8cases of LAD combined RCA and1case of LCX combinedRCA);12cases in triple vessel lesion. There were no significant collateralcirculation formation in all cases. According to the supplying by coronaryartery: there were252ischemic myocardium segments by the LAD,95ischemic myocardium segments by the LCX and110ischemic myocardiumsegments by the RCA. The myocardium segments of the control groupincluded in the analysis of the LAD,LCX and RCA were273,195,195,respectiuely. The software of3D-STI was applied to acquire the leftventricular strain including the systolic peak area strain (AS), the systolicpeak circumferential strain (CS), the systolic peak longitudinal strain (LS) andthe systolic peak radial strain (RS) for each segment, and to evaluate the valueof the strain in diagnosing CHD with ROC.Results: Compared with control group, the strains were decreased inCHD group (P<0.01). The area under receiver operating characteristics (AUC)curve of LS and AS to diagnose CHD in ischemic myocardium whichsupplying by the LAD, the LCX and the RCA were0.863,0.856,0.840and0.818,0.802,0.846, respectively. The LS was the most sensitivity and the ASwas the most specificity, they were90.1%,89.5%,89.1%and90.8%,83.1%，89.2%, respectively.Conclusions: The regional strains of ischemic myocardium weredecreased in CHD. The LS is the most sensitivity and the AS is the mostspecificity in the all of strain parameters.3D-STI can early detect regionalwall motion abnormalities caused by myocardial ischaemia in patients withCHD.