title: Relationship between color M-mode echocardiography flow propagation and cardiac iron load on MRI in patients with thalassemia major.
abstract: OBJECTIVE
  Myocardial iron overload remains an important problem and results in cardiac dysfunction in patients with thalassemia major (TM). The ratio of color M-mode flow propagation velocity to early diastolic transmitral flow velocity (E/Vp) in echocardiography is a marker of increased left ventricular filling pressure, which is independent of preload, afterload, and heart rate. We examined the relationship between E/Vp and iron loading in patients with TM using cardiac magnetic resonance imaging (MRI).
  
  
  METHODS
  Twenty-one TM patients and 21 age-matched healthy controls were enrolled in the study. Transmitral flow, pulmonary vein velocities, and Vp were obtained by two blinded echocardiographers. Left ventricular isovolumetric relaxation time (IVRT) was measured in the apical long axis by echocardiography. All patients also underwent MRI for cardiac T2* evaluation of iron overload. An increased E/Vp was defined as > 1.5.
  
  
  RESULTS
  The E/Vp ratio was increased in TM patients compared with control subjects (1.7±0.4 and 1.2±0.2, P < 0.01, respectively). There was no correlation between E/Vp and cardiac T2* value. E/Vp was significantly correlated with IVRT (r=0.51, P = 0.02). In addition, the cardiac T2* value was comparable in patients with an E/Vp > 1.5 and E/Vp ≤1.5 (21.1±9.8 ms vs. 22.3±8.0 ms, P = 0.80, respectively).
  
  
  CONCLUSIONS
  E/Vp may be a marker of diastolic abnormality that is independent from myocardial iron load in TM patients with preserved left ventricular function.
authors: Department of Radiology, Selçuk University Meram School of Medicine, Meram, Konya, Turkey. orhan.ozbek@gmail.com
authors: Orhan
authors: O
authors: Ozbek
authors: Kadir
authors: K
authors: Acar
authors: Mehmet
authors: M
authors: Kayrak
authors: Seda
authors: S
authors: Ozbek
authors: Enes Elvin
authors: EE
authors: Gül
authors: Ramazan
authors: R
authors: Uçar
authors: Yahya
authors: Y
authors: Paksoy
mesh_terms: D000293:Adolescent; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology*; D016022:Case-Control Studies; D004452:Echocardiography / Q000379:methods*; D018618:Echocardiography, Doppler, Color; D005260:Female; D006801:Humans; D019190:Iron Overload / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology; D055815:Young Adult; D017086:beta-Thalassemia / Q000150:complications* / Q000000981:diagnostic imaging* / Q000378:metabolism