Theory has it that increasing the step length improves the accuracy of a method. In order to affirm this we increased the step length of the concept in [1] by one to get k = 5. The technique of collocation and interpo...Theory has it that increasing the step length improves the accuracy of a method. In order to affirm this we increased the step length of the concept in [1] by one to get k = 5. The technique of collocation and interpolation of the power series approximate solution at some selected grid points is considered so as to generate continuous linear multistep methods with constant step sizes. Two, three and four interpolation points are considered to generate the continuous predictor-corrector methods which are implemented in block method respectively. The proposed methods when tested on some numerical examples performed more efficiently than those of [1]. Interestingly the concept of self starting [2] and that of constant order are reaffirmed in our new methods.展开更多
Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, th...Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, the effect of LBBB history on progressive heart dysfunction and clinical efficacy of cardiac resynchronization therapy （CRT） in such patients are not clear. In this study we explore the clinical efficacy and predictor of cardiac resynchronization therapy in LBBB heart dysfunction. Methods Twenty-seven LBBB patients with severe heart failure were treated with CRT. Twenty-six LBBB patients without CRT served as control. During 6 months follow-up, ECG, plasma NT-proBNP and echocardiogram indexes were measured. Results Compared with baseline, NYHA functional class of 23 patients （85.2%） was improved in CRT group. Compared with baseline and control, QRS duration （QRSd） was significantly more narrow （P = 0.023, P = 0.019）, NT-proBNP was significantly lower （P = 0.011,P = 0.009）, ventricular septal to left ventricular posterior wall delay time and left ventricular dyssynchrony index （Ts-SD） were significantly worse （P 〈 0.05）; left ventricular ejection fraction, left ventricular end-systolic volume, mitral regurgitation area were significantly improved in CRT group （P 〈 0.05）. when the LBBB history was I〉 2 years and QRSd I〉 155 ms, the sensitivity and specificity of CRT super-response were 53.4% and 85.6% respectively. Conclusions CRT can improve the synchronization and hemodynamic of LBBB patients with heart dysfunction, the LBBB history I〉 2 years and QRSd I〉 155 ms are one of the CRT super-response predictors.展开更多
This paper proposes a continuous block method for the solution of second order ordinary differential equation. Collocation and interpolation of the power series approximate solution are adopted to derive a continuous ...This paper proposes a continuous block method for the solution of second order ordinary differential equation. Collocation and interpolation of the power series approximate solution are adopted to derive a continuous implicit linear multistep method. Continuous block method is used to derive the independent solution which is evaluated at selected grid points to generate the discrete block method. The order, consistency, zero stability and stability region are investigated. The new method was found to compare favourably with the existing methods in term of accuracy.展开更多
文摘Theory has it that increasing the step length improves the accuracy of a method. In order to affirm this we increased the step length of the concept in [1] by one to get k = 5. The technique of collocation and interpolation of the power series approximate solution at some selected grid points is considered so as to generate continuous linear multistep methods with constant step sizes. Two, three and four interpolation points are considered to generate the continuous predictor-corrector methods which are implemented in block method respectively. The proposed methods when tested on some numerical examples performed more efficiently than those of [1]. Interestingly the concept of self starting [2] and that of constant order are reaffirmed in our new methods.
基金supported by Science and Technology Key Foundation of Guangdong Province(No.2010B031600166)the Science and Technology Foundation of Guangdong Province(No.2011B061300072)the Natural Science Foundation of Guangdong Province(No.7001020)
文摘Background Left bundle branch block （LBBB） results in an altered pattern of left ventricular （LV） activation and subsequent contraction. Cardiac synchrony and cardiac function are deteriorated by LBBB. However, the effect of LBBB history on progressive heart dysfunction and clinical efficacy of cardiac resynchronization therapy （CRT） in such patients are not clear. In this study we explore the clinical efficacy and predictor of cardiac resynchronization therapy in LBBB heart dysfunction. Methods Twenty-seven LBBB patients with severe heart failure were treated with CRT. Twenty-six LBBB patients without CRT served as control. During 6 months follow-up, ECG, plasma NT-proBNP and echocardiogram indexes were measured. Results Compared with baseline, NYHA functional class of 23 patients （85.2%） was improved in CRT group. Compared with baseline and control, QRS duration （QRSd） was significantly more narrow （P = 0.023, P = 0.019）, NT-proBNP was significantly lower （P = 0.011,P = 0.009）, ventricular septal to left ventricular posterior wall delay time and left ventricular dyssynchrony index （Ts-SD） were significantly worse （P 〈 0.05）; left ventricular ejection fraction, left ventricular end-systolic volume, mitral regurgitation area were significantly improved in CRT group （P 〈 0.05）. when the LBBB history was I〉 2 years and QRSd I〉 155 ms, the sensitivity and specificity of CRT super-response were 53.4% and 85.6% respectively. Conclusions CRT can improve the synchronization and hemodynamic of LBBB patients with heart dysfunction, the LBBB history I〉 2 years and QRSd I〉 155 ms are one of the CRT super-response predictors.
文摘This paper proposes a continuous block method for the solution of second order ordinary differential equation. Collocation and interpolation of the power series approximate solution are adopted to derive a continuous implicit linear multistep method. Continuous block method is used to derive the independent solution which is evaluated at selected grid points to generate the discrete block method. The order, consistency, zero stability and stability region are investigated. The new method was found to compare favourably with the existing methods in term of accuracy.
