Background: We aimed to evaluate the function of coronary collateral circulation (CCC) in the ischemic myocardium by a two-dimensional strain technique.
Methods and results: Myocardial segments for all patients were divided into three groups: no coronary collateral circulation (NCCC), CCC, and normal control. We obtained the segmental strain and the strain rate in longitudinal, radial, circumferential directions, and peak rotation and rotation rate of the left ventricle by ultrasonography. Also, the time to peak of all the strain and the strain rate were acquired. The peak systolic strain, the end systolic strain, the peak systolic strain rate in the longitudinal direction, the peak systolic strain rate in the radial direction, the peak systolic strain, the end systolic strain, the peak systolic strain rate, the peak early diastolic strain rate in the circumferential direction, the peak systolic rotation rate, and the peak early diastolic rotation rate were larger for the CCC group than the NCCC group (P<0.05). Also, the time to peak of the segments was delayed for the NCCC group than for the CCC group. Receiver operating characteristic curve analysis was performed for the late diastolic strain rate in the circumferential direction to predict the presence of CCC.
Conclusion: CCC could partially maintain the function of the related ischemic myocardium segments and prevent mechanical dyssynchrony. The two-dimensional strain technique is convenient and noninvasive for predicting the presence of CCC.