title: Right ventricular long-axis response to different chronic loading conditions: its relevance to clinical symptoms.
abstract: BACKGROUND
  The intervention timing in atrial septal defect (ASD) or pulmonary valvular stenosis (PVS) is more dependent on symptoms than right ventricular (RV) damage in clinical practice. RV long-axis function is sensitive in revealing RV myocardial dysfunction. We evaluate the impact of different chronic loading conditions on RV long-axis function and its relationship to patients' symptoms in ASD or PVS.
  
  
  METHODS
  Transthoracic echocardiography was performed in normals (n=39) and patients with isolated secundum ASD (n=45) or PVS (n=38). RV volume- and pressure-overloading were defined as the ratio of RV/left ventricular end-diastolic dimension ≥ 0.5 and RV systolic pressure ≥ 40 mmHg, respectively. RV long-axis dysfunction was defined as M-mode tricuspid annular plane systolic excursion (TAPSE) <1.6 cm. New York Heart Association (NYHA) functional class and other symptoms (decreased exercise tolerance, palpitation and chest pain) were recorded.
  
  
  RESULTS
  Thirty-nine (32.0%) had normal loading (Group 1; 39 normals); 24 (19.6%) had isolated volume-overloading (Group 2; all ASDs); 21 (17.2%) had isolated pressure-overloading (Group 3; 21 PVSs) and 38 (31.1%) had both overloading conditions (Group 4; 21 ASDs and 17 PVSs). RV long-axis dysfunction in abnormal loading groups were zero (0%, Group 2), 21 (100%, Group 3) and 22 (57.8%, Group 4) (χ(2)=45.9, p<0.001). Group 3 were more symptomatic (NYHA functional class 2.5 ± 0.6 versus 1.6 ± 0.5, p<0.05) and had lower TAPSE (1.6 ± 0.4 versus 3.0 ± 0.7 cm, p<0.05) than Group 2. RV long-axis dysfunction was the strongest predictor of the presence of symptoms (odds ratio=9.298, p<0.001).
  
  
  CONCLUSIONS
  Chronic volume-overloading accentuates while pressure-overloading attenuates RV long-axis excursion and its impairment was associated with the presence of symptoms.
authors.affiliation: Institute of Vascular Medicine and Division of Cardiology, Li Ka Shing Institute of Health Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Fang
authors.forename: Micheal Y
authors.initials: MY
authors.lastname: Henein
authors.forename: Cheuk-Man
authors.initials: CM
authors.lastname: Yu
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Mehmet G
authors.initials: MG
authors.lastname: Kaya
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Coats
authors.forename: Yat-Yin
authors.initials: YY
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D000328:Adult; D004452:Echocardiography / Q000379:methods; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006334:Heart Function Tests / Q000379:methods*; D006344:Heart Septal Defects, Atrial / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology*; D013997:Time Factors; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016278:Ventricular Function, Right / Q000502:physiology*; D055815:Young Adult