title: [The incidence, clinical characteristics and prognostic significance of a left bundle-branch block associated with an acute myocardial infarct].
abstract: To assess the current incidence and meaning of left bundle-branch block associated with acute myocardial infarction we studied 1,239 patients consecutively admitted in three hospitals. Left bundle branch block was present in 42 cases (3.3%). Compared to the patients without left bundle-branch block, those with left bundle-branch block were older (70 +/- 8.8 versus 63.9 +/- 11.4 years; p < 0.001), and had a more prevalent history of diabetes, angina, myocardial infarction and heart failure. Left bundle-branch block was associated more frequently with female gender and poor left ventricular ejection fraction. Patients with left bundle branch block were admitted with a longer interval from the onset of the symptoms (7.8 +/- 6.3 versus 5.4 +/- 6.7 hours; p < 0.01) and received in a lesser rate thrombolytics agents (21% versus 56%; p < 0.001), than those without left bundle-branch block. Complications significatively associated with left bundle-branch block were: complete AV block; heart failure and one-year mortality (40.4% versus 19.5%, p < 0.01). Female gender, age and heart failure were independent predictors of mortality whereas left bundle-branch block was not. In conclusion, current incidence of left bundle-branch block in acute myocardial infarction is lower than that referred in the pre-thrombolytic era. Left bundle-branch block is accompanied by a low rate of thrombolysis, whereas a higher mortality rate of these patients seems to depend on their clinical characteristics.
authors.affiliation: Servicio de Medicina Intensiva, Unidad Coronaria, Hospital Santa María del Rosell, Murcia.
authors.forename: A
authors.initials: A
authors.lastname: Melgarejo Moreno
authors.forename: J
authors.initials: J
authors.lastname: Galcerá Tomás
authors.forename: A
authors.initials: A
authors.lastname: García Alberola
authors.forename: A
authors.initials: A
authors.lastname: González Sánchez
authors.forename: F
authors.initials: F
authors.lastname: Jiménez Pagán
authors.forename: G
authors.initials: G
authors.lastname: Vignote Mingorance
authors.forename: J
authors.initials: J
authors.lastname: Galán Ayuso
authors.forename: P
authors.initials: P
authors.lastname: Rodríguez García
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D016009:Chi-Square Distribution; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000401:mortality; D011379:Prognosis; D011446:Prospective Studies; D017678:Sex Distribution; D013997:Time Factors