title: Prevalence and Prognostic Implications of Bundle Branch Block in Comatose Survivors of Out-of-Hospital Cardiac Arrest.
abstract: This study reports the prevalence and prognostic impact of right bundle branch block (RBBB) and left bundle branch block (LBBB) in the admission electrocardiogram (ECG) of comatose survivors of out-of-hospital cardiac arrest (OHCA). The present study is part of the predefined electrocardiographic substudy of the prospective randomized target temperature management trial, which found no benefit of targeting 33°C over 36°C in terms of outcome. Six-hundred eighty-two patients were included in the substudy. An admission ECG, which defined the present study population, was available in 602 patients (88%). These ECGs were stratified by the presence of LBBB, RBBB, or no-BBB (reference) on admission. End points were mortality and neurologic outcome 6 months after OHCA. RBBB was present in 79 patients (13%) and LBBB in 65 patients (11%), and the majority of BBBs (92%) had resolved 4 hours after admission. RBBB was associated with significantly higher 6 months mortality (RBBB: hazard ratio [HR]unadjusted1.78, 95% confidence interval [CI] 1.30 to 2.43; LBBB: HRunadjusted1.26, 95% CI 0.87 to 1.81), but this did not reach a level of significance in the adjusted model (HRadjusted1.33, 95% CI 0.94 to 1.87). Similar findings were seen for neurologic outcome in the unadjusted and adjusted analyses. RBBB was further independently associated with higher odds of unfavorable neurologic outcome (RBBB: adjusted odds ratio 1.97, 95% CI 1.05 to 3.71). In conclusion, BBBs after OHCA were transient in most patients, and RBBB was directly associated with higher mortality and independently associated with higher odds of unfavorable neurologic outcome. RBBB is seemingly an early indicator of an unfavorable prognosis after OHCA.
authors.affiliation: Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Johannes
authors.initials: J
authors.lastname: Grand
authors.affiliation: Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark. Electronic address: jakob.hartvig.thomsen.01@regionh.dk.
authors.forename: Jakob Hartvig
authors.initials: JH
authors.lastname: Thomsen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Kjaergaard
authors.affiliation: Department of Anesthesia and Intensive Care, Helsingborg Hospital, Helsingborg, Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Nielsen
authors.affiliation: Department of Cardiology, Lund University Hospital, Lund, Sweden.
authors.forename: David
authors.initials: D
authors.lastname: Erlinge
authors.affiliation: Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wiberg
authors.affiliation: Department of Cardiothoracic Anesthesia, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Wanscher
authors.affiliation: Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: John
authors.initials: J
authors.lastname: Bro-Jeppesen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital, Rigshospitalet, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Hassager
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000453:epidemiology*; D016887:Cardiopulmonary Resuscitation; D003128:Coma / Q000453:epidemiology / Q000401:mortality*; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D004554:Electric Countershock; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009422:Nervous System Diseases / Q000453:epidemiology*; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology / Q000401:mortality* / Q000628:therapy; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D017741:Survivors; D014157:Transcription Factors
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors; C066735:odd protein, Drosophila