The Study Of Left Ventricular Twist Assessed By Velocity Vector Imaging

Objective Assess the characteristic of Left Ventricular (LV) twist of health person by Velocity Vector Imaging (VVI) , and establish nomogram of LV twist from infancy to the elder. Analyze the influence of aging on LV torsional movement, and compared with the parameter measured by Speckle Tracking Echocardiography (STE) , in order to estimate the value of VVI in assessing of LV twist.Analyze the alteration of LV twist in patients with Cardiomyopathy by VVI, including Dilated Cardiomyopathy (DCM) , Hypertrophic Cardiomyopathy(HCM), Noncompaction of the Ventricular Myocardium (NVM), and Myocarditis (MC) , and compared with the normal twist parameter, routine Echocardiogram heart function index- Ejection Fraction (EF), laboratory index NT-proBNP, to discuss the value of VVI in assessing LV function of patient with Cardiomyopathy.Methods Analyze LV twist in 335 healthy volunteers (aged 12 days to 74 years) by VVI, observe the influence of age and sex on twist parameter. Draw 274 from the 335 healthy volunteers randomly, and assessed by STE, to analysis the consistency in this two methods in evaluate LV twist.Assess LV twist in 49 patients with Cardiomyopathy by VVI, measure the EF by Echocardiogram, detect the content of NT-proBNP in their blood plasma, to discuss the value of VVI in assessment LV function of Cardiomyopathy patient. Analyze the dependability in this three methods, and to evaluate the degree of LV dysfunction in s patients with cardiomyopathy.Results Different LV twist values are noted with respect to age: Peak twist (Ptw) increases gradually with advancing age, when normalized by LV length, it showed higher values before 3 years old and between 25 to 45 years old. Peak twist velocity (PtwV) increased with aging from infancy to 25 years old, and leveled off from 25 to 45 years old, then decreased with advancing age. The changes of time to peak twist velocity (TPKtw ) and % timing of peak twist in systolic duration (TPK%) are indifferent within groups. Peak untwist velocity (PutwV) showed lowest values before 3 years old, and increased with aging from 3 to 25 years old, then leveled off from 25 to 45years old, and decreased with advancing age after 45 years old. Time to peak untwist velocity (TPKutw) increased with aging, but no statistical significance are observed. The proportion of untwist in isovolumetric relaxation period (Iutw%) was lowest before 3 years old, and increased gradually from 25 to 45 years old , then decreased with aging. There are no obvious differences between different sex groups. The parameters of LV twist measured by VVI and STE have good consistency.All of the parameters of LV twist and untwist of DCM, NVM, MC groups are lower compared with control group. The systolic twist parameters of HCM group are higher, but the diastolic untwist parameters are lower than that of control group.The descendent degree of twist and untwist data in DCM, NVM, MC groups are positive correlated with the descendent degree of EF. The deadline of untwist data in HCM group are positively correlated with the deadline of EF. The changes of twist index Ptw, TPK%, and untwist index Iutw% in Cardiomyopathy group are positively correlated with the changes of the NT-proBNP concentration in their blood plasma.Conclusions VVI can be used to noninvasively and accurately assess LV twist of health person. The effect of aging on LV twist may reflect the process of maturational and adaptive modulation of LV torsional biomechanics from infancy to the elder.VVI can be used to noninvasively and accurately assess the changes of LV twist of patients with Cardiomyopathy, and the parameters are positive correlated with the routine Echocardiogram heart function index and laboratory index, provided clinic with the important LV functional data.