Left ventricular torsion and longitudinal shortening: two fundamental components of myocardial mechanics assessed by tagged cine-MRI in normal subjects
Por:
Carreras, F, Garcia-Barnes, J, Gil, D, Pujadas, S, Li, CH, Suarez-Arias, R, Leta, R, Alomar, X, Ballester, M, Pons-Llado, G
Publicada:
1 feb 2012
Resumen:
Cardiac magnetic resonance imaging (Cardiac MRI) has become a gold standard diagnostic technique for the assessment of cardiac mechanics, allowing the non-invasive calculation of left ventricular long axis longitudinal shortening (LVLS) and absolute myocardial torsion (AMT) between basal and apical left ventricular slices, a movement directly related to the helicoidal anatomic disposition of the myocardial fibers. The aim of this study is to determine AMT and LVLS behaviour and normal values from a group of healthy subjects. A group of 21 healthy volunteers (15 males) (age: 23-55 y.o., mean: 30.7 +/- A 7.5) were prospectively included in an observational study by Cardiac MRI. Left ventricular rotation (degrees) was calculated by custom-made software (Harmonic Phase Flow) in consecutive LV short axis planes tagged cine-MRI sequences. AMT was determined from the difference between basal and apical planes LV rotations. LVLS (%) was determined from the LV longitudinal and horizontal axis cine-MRI images. All the 21 cases studied were interpretable, although in three cases the value of the LV apical rotation could not be determined. The mean rotation of the basal and apical planes at end-systole were -3.71A degrees A A +/- A 0.84A degrees and 6.73A degrees A A +/- A 1.69A degrees (n:18) respectively, resulting in a LV mean AMT of 10.48A degrees A A +/- A 1.63A degrees (n:18). End-systolic mean LVLS was 19.07 +/- A 2.71%. Cardiac MRI allows for the calculation of AMT and LVLS, fundamental functional components of the ventricular twist mechanics conditioned, in turn, by the anatomical helical layout of the myocardial fibers. These values provide complementary information about systolic ventricular function in relation to the traditional parameters used in daily practice.
Filiaciones:
Carreras, F:
Hosp de la Santa Cruu & St Pau, Cardiac Imaging Unit, Dept Cardiol, Barcelona 08025, Spain
Garcia-Barnes, J:
Univ Autonoma Barcelona, Comp Vis Ctr, Bellaterra, Spain
Gil, D:
Univ Autonoma Barcelona, Comp Vis Ctr, Bellaterra, Spain
Pujadas, S:
Hosp de la Santa Cruu & St Pau, Cardiac Imaging Unit, Dept Cardiol, Barcelona 08025, Spain
Li, CH:
Hosp de la Santa Cruu & St Pau, Cardiac Imaging Unit, Dept Cardiol, Barcelona 08025, Spain
Suarez-Arias, R:
Hosp Alvarez Buylla, Cardiol Unit, Mieres, Asturias, Spain
Leta, R:
Hosp de la Santa Cruu & St Pau, Cardiac Imaging Unit, Dept Cardiol, Barcelona 08025, Spain
Alomar, X:
Clin Creu Blanca, Dept Radiol, Barcelona, Spain
Ballester, M:
Univ Lleida, Chair Cardiol, Lleida, Spain
Pons-Llado, G:
Hosp de la Santa Cruu & St Pau, Cardiac Imaging Unit, Dept Cardiol, Barcelona 08025, Spain
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