title: Left ventricular systolic dyssynchrony in patients with isolated symptomatic myocardial bridge.
abstract: OBJECTIVE
  The impact of myocardial bridge (MB) on left ventricular (LV) systolic synchrony is insufficiently understood.
  
  
  METHODS
  Thirty-five subjects with isolated mid-left, anterior, descending artery (LAD) MB, preserved LV ejection fraction (LVEF > 50%), and otherwise, normal coronary angiogram were identified from 3607 patients who underwent diagnostic coronary angiography and were evaluated by tissue Doppler imaging and real-time three-dimensional echocardiography (RT3DE). Control subjects consisted of 26 age and sex-matched coronary angiographically "normal" subjects.
  
  
  RESULTS
  MB patients were characterized by reduced, early, diastolic strain rate in LAD-supplied apical segments (lateral and anterior), with prevalence of LV systolic dyssynchrony of 25.7% (9/35). MB patients were further classified by the medians of MB stenosis and length. For MB stenosis < 52.5%, Class I: length < 17 mm (n = 7), Class II: length ≥ 17 mm (n = 10); for stenosis ≥ 52.5%, Class III: length < 17 mm (n = 10), Class IV: length ≥ 17 mm (n = 8). Binary Logistic regression model revealed that higher MB lesion classification (odds ratio: 4.944, 95%CI 1.174-20.82, P < 0.05) and hypertension (odds ratio: 15.32, 95%CI: 1.252-187.6, P < 0.05) are statistically associated with LV systolic dyssynchrony, which was independent of LV mass.
  
  
  CONCLUSIONS
  MB in the mid LAD is associated with myocardial dyssynchrony. Hypertensive individuals and those with more severe bridging (determined by length and stenosis) tend to have an increased incidence of dyssynchrony.
authors.affiliation: Institute of Cardiovascular Disease and Heart Center, Pingjin Hospital, Logistics University of Chinese People's Armed Police Forces, Tianjin, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cai
authors.forename: Yan
authors.initials: Y
authors.lastname: Dong
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.forename: Shao-Bo
authors.initials: SB
authors.lastname: Chen
authors.forename: Ji-Hong
authors.initials: JH
authors.lastname: Zhao
authors.forename: Tie-Min
authors.initials: TM
authors.lastname: Jiang
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Li
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D017023:Coronary Angiography; D003430:Cross-Sectional Studies; D003971:Diastole; D015150:Echocardiography, Doppler; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D054084:Myocardial Bridging / Q000150:complications* / Q000175:diagnosis; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D013318:Stroke Volume; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D016277:Ventricular Function, Left