title: Assessment of subclinical left ventricular dysfunction in patients with chronic mitral regurgitation using torsional parameters described by tissue Doppler imaging.
abstract: BACKGROUND
  Left ventricular (LV) twist is due to oppositely directed apical and basal rotation and has been proposed as a sensitive marker of LV function. We sought to assess the impact of chronic pure mitral regurgitation (MR) on the torsional mechanics of the left human ventricle using tissue Doppler imaging.
  
  
  METHODS
  Nineteen severe MR patients with a normal LV ejection fraction and 16 non-MR controls underwent conventional echocardiography and apical and basal short-axis color Doppler myocardial imaging (CDMI). LV rotation at the apical and basal short-axis levels was calculated from the averaged tangential velocities of the septal and lateral regions, corrected for the LV radius over time. LV twist was defined as the difference in LV rotation between the two levels, and the LV twist and twisting/untwisting rate profiles were analyzed throughout the cardiac cycle.
  
  
  RESULTS
  LV twist and LV torsion were significantly lower in the MR group than in the non-MR group (10.38° ± 4.04° vs. 13.95° ± 4.27°; p value = 0.020; and 1.29 ± 0.54 °/cm vs. 1.76 ± 0.56 °/cm; p value = 0.021, respectively), both suggesting incipient LV dysfunction in the MR group. Similarly, the untwisting rate was lower in the MR group (-79.74 ± 35.97 °/s vs.-110.96 ± 34.65 °/s; p value = 0.020), but there was statistically no significant difference in the LV twist rate.
  
  
  CONCLUSIONS
  The evaluation of LV torsional parameters in MR patients with a normal LV ejection fraction suggests the potential role of these sensitive variables in assessing the early signs of ventricular dysfunction in asymptomatic patients.
authors: Echocardiography Research Center, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors: Zahra
authors: Z
authors: Ojaghi-Haghighi
authors: Echocardiography Research Center, Shariati Medical and Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors: Atoosa
authors: A
authors: Mostafavi
authors: Cardiovascular Research Center, Guilan University of Medical Sciences, Rasht, Iran.
authors: Hassan
authors: H
authors: Moladoust
authors: Echocardiography Research Center, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors: Feridoun
authors: F
authors: Noohi
authors: Echocardiography Research Center, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors: Majid
authors: M
authors: Maleki
authors: Echocardiography Research Center, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors: Maryam
authors: M
authors: Esmaeilzadeh
authors: Echocardiography Research Center, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
authors: Niloofar
authors: N
authors: Samiei
keywords: Elasticity imaging techniques; Heart ventricles; Mitral valve insufficiency