title: Endocardial radiofrequency ablation for hypertrophic obstructive cardiomyopathy: acute results and 6 months' follow-up in 19 patients.
abstract: OBJECTIVE
  The purpose of this study was to examine the efficacy and safety of endocardial radiofrequency ablation of septal hypertrophy (ERASH) for left ventricular outflow tract (LVOT) gradient reduction in hypertrophic obstructive cardiomyopathy (HOCM).
  
  
  BACKGROUND
  Anatomic variability of the vessels supplying the obstructing septal bulge can limit the efficacy of transcoronary ablation of septal hypertrophy in HOCM. Previous studies showed that inducing a local contraction disorder without reducing septal mass results in effective gradient reduction. We examined an alternative endocardial approach to transcoronary ablation of septal hypertrophy by using ERASH.
  
  
  METHODS
  Nineteen patients with HOCM were enrolled; in 9 patients, the left ventricular septum was ablated, and in 10 patients, the right ventricular septum was ablated. Follow-up examinations (echocardiography, 6-min walk test, bicycle ergometry) were performed 3 days and 6 months after ERASH.
  
  
  RESULTS
  After 31.2 ± 10 radiofrequency pulses, a significant and sustained LVOT gradient reduction could be achieved (62% reduction of resting gradients and 60% reduction of provoked gradients, p = 0.0001). The 6-min walking distance increased significantly from 412.9 ± 129 m to 471.2 ± 139 m after 6 months, p = 0.019); and New York Heart Association functional class was improved from 3.0 ± 0.0 to 1.6 ± 0.7 (p = 0.0001). Complete atrioventricular block requiring permanent pacemaker implantation occurred in 4 patients (21%); 1 patient had cardiac tamponade.
  
  
  CONCLUSIONS
  ERASH is a new therapeutic option in the treatment of HOCM, allowing significant and sustained reduction of the LVOT gradient as well as symptomatic improvement with acceptable safety by inducing a discrete septal contraction disorder. It may be suitable for patients not amenable to transcoronary ablation of septal hypertrophy or myectomy.
authors.affiliation: Department of Cardiology, Klinikum Bielefeld, Germany. thorsten.lawrenz@sk-bielefeld.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Lawrenz
authors.forename: Bianca
authors.initials: B
authors.lastname: Borchert
authors.forename: Christian
authors.initials: C
authors.lastname: Leuner
authors.forename: Markus
authors.initials: M
authors.lastname: Bartelsmeier
authors.forename: Jens
authors.initials: J
authors.lastname: Reinhardt
authors.forename: Claudia
authors.initials: C
authors.lastname: Strunk-Mueller
authors.forename: Dorothee
authors.initials: D
authors.lastname: Meyer Zu Vilsendorf
authors.forename: Marc
authors.initials: M
authors.lastname: Schloesser
authors.forename: Gerald
authors.initials: G
authors.lastname: Beer
authors.forename: Frank
authors.initials: F
authors.lastname: Lieder
authors.forename: Christoph
authors.initials: C
authors.lastname: Stellbrink
authors.forename: Horst
authors.initials: H
authors.lastname: Kuhn
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D017115:Catheter Ablation / Q000379:methods*; D004699:Endocardium / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors