title: Sequential Atrioventricular Pacing in Patients With Hypertrophic Cardiomyopathy: An 18-year Experience.
abstract: OBJECTIVE
  Controversy persists regarding the role of sequential atrioventricular pacing in patients with obstructive hypertrophic cardiomyopathy and disabling symptoms. The aim of this study was to evaluate the effect of pacing on symptoms, dynamic gradient, and left ventricular function in patients with hypertrophic cardiomyopathy.
  
  
  METHODS
  From 1991 to 2009, dual-chamber pacemakers were implanted in 82 patients with obstructive hypertrophic cardiomyopathy and disabling symptoms despite optimal medical therapy. Sequential pacing was performed with a short atrioventricular delay. Clinical and echocardiographic parameters were measured before and immediately after implantation and after a long follow-up (median, 8.5 years [range, 1-18 years]).
  
  
  RESULTS
  The New York Heart Association functional class was immediately reduced after pacemaker implantation in 95% of patients (P < .0001), and this improvement was maintained until the final follow-up in 89% (P = .016). The gradient was significantly reduced after implantation (94.5 ± 36.5 vs 46.4 ± 26.7mmHg; P < .0001) and at final follow-up (94.5 ± 36.5 vs 35.9 ± 24.0mmHg; P < .0001). Mitral regurgitation permanently improved in 52% of the patients (P < .0001). There were no differences in ventricular thickness or diameters, ejection fraction, or diastolic function.
  
  
  CONCLUSIONS
  Sequential pacing in selected patients with obstructive hypertrophic cardiomyopathy improves functional class and reduces dynamic gradient and mitral regurgitation immediately after pacemaker implantation and at final follow-up. Prolonged ventricular pacing has no negative effects on systolic or diastolic function in these patients.
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Jurado Román
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain. Electronic address: jmmonterocabezas@gmail.com.
authors.forename: José M
authors.initials: JM
authors.lastname: Montero Cabezas
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Belén
authors.initials: B
authors.lastname: Rubio Alonso
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: García Tejada
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Felipe
authors.initials: F
authors.lastname: Hernández Hernández
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Agustín
authors.initials: A
authors.lastname: Albarrán González-Trevilla
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: María T
authors.initials: MT
authors.lastname: Velázquez Martín
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Coma Samartín
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Rodríguez García
authors.affiliation: Departamento de Cardiología, Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: Juan C
authors.initials: JC
authors.lastname: Tascón Pérez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*; D014694:Ventricular Outflow Obstruction / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D055815:Young Adult
keywords: Diastole; Diástole; Hypertrophic cardiomyopathy; Marcapasos; Miocardiopatía hipertrófica; Obstrucción; Obstruction; Pacemakers; Systole; Sístole