RESUMEN
Left ventricular rotation is composed of systolic twist and diastolic untwist.The opposite motion of subendocardium and subepicardium,causing the left ventricular twist,fiurther leads to left ventricular systolic ejection.Then the left ventricular cardium in diastole rapidly retracts and releases the potential energy stored,which causes the early rapidly filling of left ventricle.Actually any physiological and pathologic changes that affect the state of the cardium can cause a change in left ventricular rotation.Also the left ventricular twist is determined and affected by the degree of myocardial contraction and relaxation,the preload and afterload,the balance of contraction between the subendocardium and subepicardium together with the myocardium orientation.The left ventricular untwist is influenced by the peak of left ventricular twist,left ventricular elastic energy,the myocardial relaxation characters and other factors,such as age and motition.In this paper,the research progress of left ventricular rotation is reviewed to promote its clinical application.
RESUMEN
Objective To evaluate the characteristics of left ventricular twisting (LVtw) and untwisting (LVuntw) in patients with dilated cardiomyopathy (DCM). MethodsNineteen DCM patients (aged 18-82 years, mean 50.52±17.52 years, 2 females) and 21 normal controls (aged 18-80 years, mean 49.05±16.94 years, 5 females) were enrolled in present study. Basal and apical short axis view of two-dimensional images of left ventricle were obtained to analyze LV rotation, and the LV rotation velocity was detected by velocity vector imaging (VVI). LVtw, LVtw velocity, untwisting velocity and untwisting rate (untwR) were calculated. ResultsThe rotated degree and velocity of the basal and apical parts of LV myocardium were irregularly changed along with the cardiac cycle in the DCM group. The rotation degree and rotation velocity at the basal and apex axis decreased in DCM group compared with that in normal group, while the peak of twisting (Ptw) [(6.49±1.82)°] and the peak of twisting velocity (PTV) [(67.84±15.60)°/s] decreased significantly in DCM group. The untwR and peak of untwisting velocity (PUV) were also decreased significantly in DCM patients. ConclusionThe Ptw, PTV and PUV decrease significantly, and the LV untwR, impacted by the preload, is also decreased significantly in DCM patients.