title: Persistence of systolic and diastolic regional dysfunction after brief episodes of myocardial ischemia evaluated with velocity vector imaging.
abstract: BACKGROUND
  The time course and characteristics of persistent regional dysfunction after ischemia remain unclear. Velocity vector imaging (VVI) allows accurate quantification of regional myocardial function. The aim of this study was to characterize the time course of regional diastolic and systolic abnormality after recovery from different durations of ischemia by VVI.
  
  
  METHODS
  72 rats underwent brief left coronary occlusion (3, 5, 10 and 15 min, respectively) followed by reperfusion for 4-8h. Hemodynamic measurements and VVI were performed at various time points. Regional systolic and diastolic functions were estimated from peak diastolic and systolic circumferential strain rate (SR-d and SR-s) of the left ventricle, respectively.
  
  
  RESULTS
  Both SR-d and SR-s were significantly decreased in the ischemic segment during occlusion compared to non-ischemic segment. With the increase in occlusive time, the duration of reduced SR-d and SR-s after reperfusion was prolonged. Both SR-d and SR-s returned to pre-occlusion values in less than 30 min after reperfusion in the 3 min and 5 min ischemia groups. However, in the 10- and 15-min ischemia groups, SR-d did not fully recovered even at 240 min after reperfusion despite complete recovery of SR-s. The left ventricular hemodynamics during occlusion were significantly changed in all groups and returned to baseline immediately after reperfusion.
  
  
  CONCLUSIONS
  The persistence of diastolic regional dysfunction is longer than systolic regional dysfunction after a relative longer ischemic event, suggesting that recent myocardial ischemic insult mimicking variant angina may be recognized with the evaluation of regional diastolic function.
authors.affiliation: Organ Failure Key Laboratory of Ministry of Education, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: Dongdong
authors.initials: D
authors.lastname: Chen
authors.forename: Yulin
authors.initials: Y
authors.lastname: Liao
authors.forename: Qiulin
authors.initials: Q
authors.lastname: Xu
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Weilan
authors.initials: W
authors.lastname: Wu
authors.forename: Juefei
authors.initials: J
authors.lastname: Wu
authors.forename: Wangjun
authors.initials: W
authors.lastname: Liao
authors.forename: Dingli
authors.initials: D
authors.lastname: Xu
authors.forename: Yili
authors.initials: Y
authors.lastname: Liu
authors.forename: Pingsheng
authors.initials: P
authors.lastname: Wu
authors.forename: Jianping
authors.initials: J
authors.lastname: Bin
mesh_terms: D000818:Animals; D003971:Diastole / Q000502:physiology*; D004562:Electrocardiography / Q000379:methods*; D007442:Intubation, Intratracheal / Q000379:methods; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D013599:Systole / Q000502:physiology*; D013997:Time Factors