title: [Right ventricular septal stimulation would produce similar bi-ventricular dyssynchrony as does apical stimulation in patients with normal ejection fraction].
abstract: OBJECTIVE
  To determine in patients with normal ejection fraction, undergoing permanent VVI pacing, if medial septal stimulation has lower dyssynchrony than apical stimulation assessed by echocardiography.
  
  
  METHODS
  A prospective trial, 19 patients>70 years old, scheduled for VVI pacemaker implantation for complete degenerative atrioventricular block, ventricular frequency<50beat per minute and ejection fraction≥45%. Patients with atrial fibrillation, heart failure, left bundle branch block and QRS durations longer than 120milliseconds in surface electrocardiogram with sinus rhythm were excluded. Patients were randomized to apical implantation group A: 47% and septal implantation group B: 53%. Echocardiographic parameters were measured previous to the implant, 48h, 5 and 48 months after implantation.
  
  
  RESULTS
  No patients had diagnosis of ischemic cardiomyopathy or heart failure. Echocardiographic parameters for interventricular dyssynchrony between groups were A: 14.44±19.76msec vs. B: 9±36.45msec; A: 6.11±62.11msec vs. B: 13±38.31msec; A: 77±53.51msec vs. B: 24.29±80.90msec, P=NS). For interventricular dyssynchrony were A: 46.44±19.76msec vs. B: 42.20±29.56msec; A: 45.33±45.67msec vs. B: 29.80±44.66msec; A: 46,38±20 msec vs. B: 21±27.20msec, P=NS) at 48h, 5 and 48 months, respectively.
  
  
  CONCLUSIONS
  Apical site of stimulation does not increase ventricular dyssynchrony rate in patients with preserved ejection fraction. Septal stimulation showed decreased trend in interventricular dyssynchrony.
authors.affiliation: Residencia de Cardiología Clínica, Instituto de Cardiología de Corrientes Juana Francisca Cabral, Corrientes, Corrientes, Argentina. Electronic address: juanmanuellange@yahoo.com.ar.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Lange
authors.affiliation: Departamento de Cardiología y Electro Fisiología, Instituto de Cardiología de Corrientes Juana Francisca Cabral, Corrientes, Corrientes, Argentina.
authors.forename: Hector
authors.initials: H
authors.lastname: Manzolillo
authors.affiliation: Departamentos de Cardiología y Ecocardiografía, Instituto de Cardiología de Corrientes Juana Francisca Cabral, Corrientes, Corrientes, Argentina.
authors.forename: Jorge
authors.initials: J
authors.lastname: Parras
authors.affiliation: Departamento de Cardiología y Electro Fisiología, Instituto de Cardiología de Corrientes Juana Francisca Cabral, Corrientes, Corrientes, Argentina.
authors.forename: Domingo
authors.initials: D
authors.lastname: Pozzer
authors.affiliation: Departamento de Cardiología y Electro Fisiología, Instituto de Cardiología de Corrientes Juana Francisca Cabral, Corrientes, Corrientes, Argentina.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Reyes
authors.affiliation: Departamento de Cardiología y Electro Fisiología, Instituto de Cardiología de Corrientes Juana Francisca Cabral, Corrientes, Corrientes, Argentina.
authors.forename: Rolando
authors.initials: R
authors.lastname: Pantich
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D013318:Stroke Volume
keywords: Argentina; Cardiac resynchronization; Disincronía; Marcapasos; Pacemaker; Resincronización cardiaca; Resincronización ventricular; Sitio de estimulación; Stimulation site; Ventricular dyssynchrony; Ventricular resynchronization