title: Left ventricular stiffness estimated by diastolic wall strain is associated with paroxysmal atrial fibrillation in structurally normal hearts.
abstract: BACKGROUND
  Left ventricular (LV) diastolic dysfunction depends on an impaired relaxation and stiffness. Abnormal LV relaxation contributes to the development of atrial fibrillation (AF), but the role of LV stiffness in AF remains unclear.
  
  
  OBJECTIVE
  Diastolic wall strain (DWS), a load-independent, noninvasive direct measure of LV stiffness, correlates with prevalent AF.
  
  
  METHODS
  This study included 328 consecutive subjects with structurally normal hearts: 164 paroxysmal AF patients and 164 age- and sex-matched (1:1) controls. We calculated the DWS from the M-mode echocardiographic measurements of the LV posterior wall thickness at end-systole and end-diastole during sinus rhythm.
  
  
  RESULTS
  The DWS was lower in the AF patients (0.35 ± 0.07) than in the controls (0.41 ± 0.06; P < 0.001). After adjusting for the risk factors of AF using a conditional logistic regression analysis, a history of hypertension, plasma brain-type natriuretic peptide level, and DWS were independently associated with AF prevalence, whereas body mass index, LV mass index, left atrial volume, and any conventional indices of the diastolic function were not. A low DWS (<0.380) was the strongest indicator of AF (odds ratio: 6.22, 95% confidence interval: 3.08-14.2, P < 0.001).
  
  
  CONCLUSIONS
  Increased LV stiffness estimated by DWS was a strong determinant of the prevalence of AF. LV stiffness may play a role in the pathogenesis of paroxysmal AF in structurally normal hearts.
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Uetake
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.
authors.forename: Katsuhito
authors.initials: K
authors.lastname: Kato
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyauchi
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Seino
authors.affiliation: Department of Cardiovascular Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Shimizu
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D003971:Diastole; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D013614:Tachycardia, Paroxysmal / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology
keywords: Atrial fibrillation; Diastolic dysfunction; Diastolic wall strain; Stiffness