title: Changes in left ventricular ejection fraction and coronary flow reserve after coronary microembolization.
abstract: BACKGROUND
  Although coronary microembolization (CME) is a frequent phenomenon in patients undergoing percutaneous coronary intervention, few data are available on the changes in left ventricular ejection fraction (LVEF) and coronary flow reserve (CFR) after CME.
  
  
  METHODS
  In this study, six miniature swine of either sex (body weight 21-25 kg) were used to prepare a CME model. After coronary angiography, 1.2 × 10(5) microspheres (42 µm) were selectively infused into the left anterior descending artery via an infusion catheter. Left ventricular ejection fraction was evaluated using transthoracic echocardiography; myocardial blood flow was measured using coloured microspheres; and CFR and coronary pressure were measured using Doppler and a pressure wire.
  
  
  RESULTS
  Left ventricular ejection fraction was 0.77 ±0.08 at baseline, 0.69 ±0.08 at 2 h, 0.68 ±0.08 at 6 h, and 0.76 ±0.06 at 1 week (2 h vs. baseline p < 0.05; 6 h vs. baseline p < 0.01). After CME, left ventricular end systolic volume (LVESV) and end diastolic volume (LVEDV) were significant larger 1 week later (p < 0.01 for both), while CFR was significantly reduced at 6 h (1.24 ±0.10 at 6 h vs. 1.77 ±0.30 at baseline, p < 0.01) and myocardial blood flow remained unchanged. Serum ET-1 level was significantly higher only at 6 h after CME (6 h vs. baseline p < 0.05).
  
  
  CONCLUSIONS
  Reduction of CFR and LVEF is significant at 6 h after CME and recovers 1 week later with left ventricular dilation.
authors.affiliation: Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China.
authors.forename: Jianying
authors.initials: J
authors.lastname: Ma
authors.forename: Juying
authors.initials: J
authors.lastname: Qian
authors.forename: Junbo
authors.initials: J
authors.lastname: Ge
authors.forename: Xin
authors.initials: X
authors.lastname: Zeng
authors.forename: Aijun
authors.initials: A
authors.lastname: Sun
authors.forename: Shufu
authors.initials: S
authors.lastname: Chang
authors.forename: Zhangwei
authors.initials: Z
authors.lastname: Chen
authors.forename: Yunzeng
authors.initials: Y
authors.lastname: Zou