title: Impact of Septal Reduction on Left Atrial Size and Diastole in Hypertrophic Cardiomyopathy.
abstract: OBJECTIVE
  Both myectomy and alcohol septal ablation (ASA) can substantially reduce left ventricular (LV) outflow obstruction, relieve symptoms, and improve outcomes in hypertrophic cardiomyopathy (HCM). It is unclear whether septal reduction decreases left atrial (LA) size and improves diastolic function. The aim of this study was to analyze the consequences of septal reduction on LA size and diastolic function in a cohort of patients with HCM.
  
  
  METHODS
  Forty patients (mean age: 50 ± 14, male sex 64%) with HCM who underwent septal reduction (myectomy or alcohol septal ablation) were studied. Retrospective analyses of echocardiograms preprocedure, postprocedure, and at 1 year of follow-up were performed.
  
  
  RESULTS
  Thirty-one patients had septal myectomy and 9 ASA. The degree of reduction in rest peak LV outflow tract gradient was significant (57 ± 32 vs. 23 ± 20 mmHg at 1 year, P < 0.001). Maximal interventricular septal thickness decreased from 22 ± 6 mm preprocedure to 19 ± 4 mm postprocedure (P < 0.001); moderate-to-severe mitral regurgitation (MR) was initially present in 34% of the sample and only 2% after the procedure. Average LA volume index (LAVI) decreased from 63 ± 20 to 55 ± 20 mL/m(2) at the 1-year follow-up (P < 0.001). We did not observe a significant improvement in diastolic function at Doppler (E/A 1.2 ± 0.4 vs. 1.1 ± 0.5, P = 0.07; E' 7.6 ± 3.6 vs. 6.9 ± 3.0, P = 0.4) pre- and postprocedure, respectively). At 1 year, only 5% of the patients were severely symptomatic (NYHA III). On multivariate analysis, a significant change in the LVOT gradient during stress (Δ gradient ≥30 mmHg) was the only variable independently associated with LAVI reverse remodeling >10 mL/m(2) [OR = 6.4 (CI 95% 1.12-36.44), P = 0.04].
  
  
  CONCLUSIONS
  Septal reduction is effective in the relief of LV obstruction and symptoms in patients with HCM. The hemodynamic changes result in a significant LA reverse remodeling, but not in an improvement of diastolic function in these patients.
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.|Cardiovascular Sciences Research Centre, St. George's University of London, London, UK.
authors.forename: Gherardo
authors.initials: G
authors.lastname: Finocchiaro
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.|Stanford Cardiovascular Institute, Stanford, California.
authors.forename: Francois
authors.initials: F
authors.lastname: Haddad
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Yukari
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.|Stanford Cardiovascular Institute, Stanford, California.
authors.forename: David
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Pavlovic
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.|Stanford Cardiovascular Institute, Stanford, California.
authors.forename: Ingela
authors.initials: I
authors.lastname: Schnittger
authors.affiliation: Cardiovascular Department, Ospedali Riuniti and University of Trieste, Trieste, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Emma
authors.initials: E
authors.lastname: Magavern
authors.affiliation: Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Myers
authors.affiliation: Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Victor
authors.initials: V
authors.lastname: Froelicher
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.|Stanford Cardiovascular Institute, Stanford, California.
authors.forename: Joshua W
authors.initials: JW
authors.lastname: Knowles
authors.affiliation: Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California.|Stanford Cardiovascular Institute, Stanford, California.
authors.forename: Euan
authors.initials: E
authors.lastname: Ashley
mesh_terms: D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D004452:Echocardiography / Q000379:methods; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D006346:Heart Septum / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery*
keywords: hypertrophic cardiomyopathy; left atrial enlargement; septal reduction