Objective: To study the protective effects of the coronary collateral circulation to ischemic myocardial regional function with coronary artery stenosis ≥75 % using 2D-strain.
Methods: Two-dimensional images of apical four-, two-chambers, long-axis views and LV short-axis views were obtained in 121 patients. According to the coronary angiogram, 121 patients were divided into 3 groups: group 1 with normal coronary artery ; group 2, with stenosis ≥75% in ≥ 1 main coronary artery involved right coronary artery, left anterior descending branch, and left circumflex branch and with the presence of coronary collateral circulation(CCC); group 3, with stenosis ≥75% in ≥ 1 main coronary artery but with no presence of CCC. We analyzed the segments’ systolic peak strain (Sps), strain rate (SRs), end systolic strain (Ses), early diastolic strain rate (SRe) and late diastolic strain rate (SRa) in longitudinal(L), radial(R), circumficial (C) directions and the rotation (Rot), rotation rate with EchoPAC offline software.
Results: Compared with 1 group, LSps, LSes, LSRs, LSRa, RSRe, RSRa, CSRe, Rotsre, Rotsra of 2 group, LSps, LSes, LSRs, LSRa, LSRe, RSes, RSRs, RSRe, RSRa, CSps, CSes, CSRs, CSRe, CSRs, Rotps, Rotsrs, Rotsre, Rotsra of 3 group decreased significantly (p<0.05); compared with 2 group, LSps, LSes, LSRs, RSes, RSRs, CSps, CSes, CSRs, CSRa, Rotps, Rotsrs, Rotsre of 3 group decreased markedly (p<0.05).
Conclusions: Coronary collateral circulation provides a protection to ischemic myocardial regional function. 2D-strain may serve as an efficient method to assess ischemic myocardial regional function .
Keywords: Coronary collateral circulation; Myocardial ischemia; Echocardiography; 2-D Strain