title: Prevalence and long-term prognosis of patients with complete bundle branch block (right or left bundle branch) with normal left ventricular ejection fraction referred for stress echocardiography.
abstract: BACKGROUND
  The prognostic value of stress echocardiography (SE) in patients with complete bundle branch blocks (BBB) with normal left ventricular ejection fraction (LVEF) has not been well described. We sought to determine the prognostic value of SE in patients with BBB and normal LVEF.
  
  
  METHODS
  We analyzed 7214 patients (58 ± 14 years; 57% female) with a mean follow-up time of 9 ± 4 years. Dobutamine SE was performed in 51% of patients and exercise SE was performed in 49%. All-cause mortality data were obtained from the Social Security Death Index.
  
  
  RESULTS
  There were 222 (3%) patients with right bundle branch block (RBBB) and 50 (0.7%) patients with left bundle branch block (LBBB). Patients with LBBB were 3 times more likely to have an abnormal stress test after adjusting for age, gender, mode of stress test, and coronary artery disease risk factors (OR = 3.3; 95% CI: 1.86-5.92; P < 0.001). The mortality rates were 4.5%/year for patients with LBBB, 2.5%/year for patients with RBBB, and 1.9%/year for patients without BBB (P < 0.001). Among patients with a normal SE, those with LBBB had similar mortality to those without LBBB (HR = 0.9; 95% CI: 0.4-2.2; P = 0.8). Patients with LBBB and abnormal SE had more than 2 times greater risk of all-cause mortality (HR = 2.4; 95% CI: 1.4-4.2; P = 0.002).
  
  
  CONCLUSIONS
  A normal stress echocardiogram in LBBB is associated with benign prognosis while those with LBBB and abnormal SE have the worst outcomes.
authors.affiliation: Mount Sinai St. Luke's and Roosevelt, Icahn School of Medicine at Mount Sinai, New York, New York.
authors.forename: Azhar A
authors.initials: AA
authors.lastname: Supariwala
authors.forename: Jose Ricardo F
authors.initials: JR
authors.lastname: Po
authors.forename: Sameh
authors.initials: S
authors.lastname: Mohareb
authors.forename: Farhan
authors.initials: F
authors.lastname: Aslam
authors.forename: Firas
authors.initials: F
authors.lastname: Kaddaha
authors.forename: Zainab I
authors.initials: ZI
authors.lastname: Mian
authors.forename: Farhan
authors.initials: F
authors.lastname: Chaudhry
authors.forename: Ahmed
authors.initials: A
authors.lastname: Otokiti
authors.forename: Farooq A
authors.initials: FA
authors.lastname: Chaudhry
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000453:epidemiology* / Q000401:mortality*; D004280:Dobutamine; D025401:Echocardiography, Stress / Q000706:statistics & numerical data*; D005080:Exercise Test / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D015996:Survival Rate; D014665:Vasodilator Agents
chemical_list: D014665:Vasodilator Agents; D004280:Dobutamine
keywords: left bundle branch block; right bundle branch block; stress echocardiography; survival