title: Atrium electromechanical interval in left ventricular diastolic dysfunction.
abstract: BACKGROUND
  Left ventricular (LV) diastolic dysfunction has great effects on the left atrium (LA). A recently developed electromechanical interval (PA-TDI), which was determined as the time interval from the initiation of P wave deflection to the peak of local lateral LA tissue Doppler imaging signal, was reported to be associated with LA electrophysiological properties. The goal of our study was to evaluate the association between the PA-TDI interval and LV diastolic function.
  
  
  METHODS
  A total of 224 consecutive patients were enrolled. LV diastolic dysfunction was defined as either (i) impaired relaxation: E/A ratio < 0·75 and E/E' ratio < 10, (ii) pseudonormal pattern: 0·75 ≤ E/A ratio < 1·5 and E/E' ratio > 10 or (iii) restrictive pattern: E/A ratio ≥ 1·5 and E/E' ratio > 10. The PA-TDI intervals were measured and compared between patients with and without diastolic dysfunction.
  
  
  RESULTS
  Fifty-six per cent of the study population had abnormal diastolic function. The PA-TDI interval was significantly longer in the diastolic dysfunction group than that in the normal group (147·8 ± 18·2 vs. 130·4 ± 17·0 ms, P < 0·01). In patients with diastolic dysfunction, the PA-TDI intervals became progressively longer as the diastolic dysfunction progressed from impaired relaxation (141·2 ± 11·4 ms), pseudonormal pattern (147·6 ± 18·0 ms) to restrictive pattern (164·1 ± 20·9 ms).
  
  
  CONCLUSIONS
  The PA-TDI interval was significantly longer in patients with LV diastolic dysfunction than those without it. Its prolongation may reflect the severity of atrial remodelling because of the abnormal diastolic function of LV.
authors.affiliation: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Tze-Fan
authors.initials: TF
authors.lastname: Chao
authors.forename: Kang-Ling
authors.initials: KL
authors.lastname: Wang
authors.forename: Chi-Fang
authors.initials: CF
authors.lastname: Chuang
authors.forename: Shih-Ann
authors.initials: SA
authors.lastname: Chen
authors.forename: Wen-Chung
authors.initials: WC
authors.lastname: Yu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003627:Data Interpretation, Statistical; D003971:Diastole / Q000502:physiology*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult