An Early Incipient and Novel Bidirectional Alteration of Myocardial Function in Coronary Artery Stenosis: Quantitative Assessment of Myocardial Regional Function with Varying Ischemic Severity by Velocity Vector Imaging

  • Dr Xiaoling Liu, Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Pu, China
  • Dr Min Feng, Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public, China
  • Dr Liang Chen, Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public
  • Prof Jifu Li, Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public
  • Prof Yun Zhang, Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public
  • Prof Mei Zhang, Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public

    • Objective: To determine the alterations of myocardial regional function with varying ischemic severity using velocity vector imaging.
    Methods: 2-D images of apical 4-chamber, 2-chamber and long-axis views were obtained in 50 patients with coronary artery disease. Myocardial segments were divided into 5 groups on the basis of coronary artery stenosis: normal, normal coronary artery; grade 1, stenosis <50%; grade 2, stenosis 50%-74%; grade 3, stenosis 75%-99%; and grade 4, occluded artery. We analyzed the segments’ systolic velocity (VS), strain (S) and strain rate (SRS); early diastolic velocity (VE) and strain rate (SRE); late diastolic velocity (VA) and strain rate (SRA); and ratio of VE to VA (VE/VA) and SRE to SRA (SRE/SRA).
    Results: Compared with normal group, VS, VE, SRE and SRE/SRA decreased even with <50% stenosis; S, SRS and VE/VA decreased with ≥50% stenosis, and VA decreased with ≥75% stenosis. Moreover, a novel bidirectional change was shown among groups: S, SRS and SRA with grade 2 stenosis were lower than those with grade 1 stenosis (P < 0.05, P < 0.001 and P < 0.05, respectively), whereas S, SRS and SRE with grade 3 stenosis were higher than those with grade 2 stenosis (P < 0.05). Grade 4 group showed the worst function.
    Conclusions: In patients with coronary artery disease, incipient myocardial dysfunction occurs with coronary artery stenosis < 50%, and regional function shows a bidirectional alteration during ischemia, which can have implications for treatment.