title: Symptoms in severe aortic stenosis are associated with decreased compensatory circumferential myocardial mechanics.
abstract: BACKGROUND
  Symptomatic patients with severe aortic stenosis (AS) demonstrate abnormal left ventricular (LV) mechanics. The aim of this study was to compare mechanics in asymptomatic and symptomatic patients with severe AS using two-dimensional myocardial strain imaging.
  
  
  METHODS
  One hundred fifty-four patients with severe AS (aortic valve area ≤ 1.0 cm(2)) referred to a heart valve clinic from 2004 to 2011 were studied. Thirty patients were asymptomatic, with normal LV ejection fractions (≥ 55%), without other significant valvular disease or wall motion abnormalities. Thirty-two symptomatic patients who underwent early aortic valve replacement, with similar age, gender, LV ejection fraction, and aortic valve area, were selected for comparison. Both groups were also compared with 32 healthy subjects with similar age and gender distributions and normal echocardiographic results who served as controls. LV longitudinal and circumferential strain and rotation were measured using speckle-tracking software applied to archived echocardiographic studies. Conventional echocardiographic and myocardial mechanical parameters were compared among the study subgroups.
  
  
  RESULTS
  Patients with asymptomatic severe AS demonstrated smaller reductions in longitudinal strain, higher (supernormal) apical circumferential strain (-38 ± 6% vs -35 ± 4%, P < .05), and extreme (supernormal) apical rotation (12.2 ± 4.9° vs 2.9 ± 1.7°, P < .0005) compared with symptomatic patients. Apical rotation < 6° was the single significant predictor of symptoms in logistic regression analysis of clinical, echocardiographic, and mechanical parameters. Twelve asymptomatic patients underwent eventual aortic valve replacement and showed decreases in strain and apical rotation compared with baseline values.
  
  
  CONCLUSIONS
  Longitudinal strain was uniformly low in patients with severe AS and lower in those with symptoms. Compensatory circumferential myocardial mechanics (increased apical circumferential strain and rotation) were absent in symptomatic patients. Thus, myocardial mechanics may help in the follow-up of patients with severe AS and timing of valve surgery.
authors.affiliation: Department of Cardiology, Rambam Health Care Campus, Haifa, Israel; Technion - Israel Institute of Technology, Haifa, Israel. Electronic address: shemy.carasso@gmail.com.
authors.forename: Shemy
authors.initials: S
authors.lastname: Carasso
authors.affiliation: Department of Cardiology, Rambam Health Care Campus, Haifa, Israel.
authors.forename: Diab
authors.initials: D
authors.lastname: Mutlak
authors.affiliation: Department of Cardiology, Rambam Health Care Campus, Haifa, Israel; Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Lessick
authors.affiliation: Department of Cardiology, Rambam Health Care Campus, Haifa, Israel; Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Shimon A
authors.initials: SA
authors.lastname: Reisner
authors.affiliation: University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Harry
authors.initials: H
authors.lastname: Rakowski
authors.affiliation: Department of Cardiology, Rambam Health Care Campus, Haifa, Israel; Technion - Israel Institute of Technology, Haifa, Israel.
authors.forename: Yoram
authors.initials: Y
authors.lastname: Agmon
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016022:Case-Control Studies; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D011379:Prognosis; D012016:Reference Values; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology*; D062606:Tertiary Care Centers; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: Aortic stenosis; Myocardial mechanics; Rotation; Strain