Effect Of The Preload On Tissue Doppler Imaging Evaluating Left Ventricular Function

Part one: Effect of the Preload on Tissue Doppler Imaging Evaluating Left Ventricular Diastolic FunctionObjective:To assess whether the diastolic parameters measured by tissue Doppler imaging(TDI) are influenced by preload.Methods: Thrity patients with chronic renal failure without overt heart disease receiving regular hemodialysis:thirteen patients with the hemodialysis amount less than 2 kg(group A), seventeen patients with the hemodialysis amount more than 2 kg(group B). All these patients were studied by corlor pulsed-wave Dopller imaging(CPWDI) and pulsed wave tissue Doppler imaging (PW-TDI) within one hour before and after hemodialysis. Early(E) and atrial(A) peak transmitral flow velocities, peak pulmonary veins systolic(s) and diastolic(d) flow velocities were recorded by CPWDI(E,A,s,d). PW-TDI sample volume was placed at the mitral annular and midsegment of septal, lateral, anterior, inferior, and posterior walls of the left ventricle. The mean of peak systolic annular and myocardial velocity, peak early diastolic annular and myocardial, and peak late diastolic annular and myocardial velocities were measured(Sa,Sm,Ea,Em,Aa,Am).Results: In groupA, the change of diastolic parameters showed insignificant chang except LAV, RAV, Em and Em/Am(P<0.05). In group B, the change of all parameters showed statistically significant difference except A, Aa, Am, Sa and Sm. E, E/A ratio, s and d decreased, while s/d increased after hemodialysis(P<0.05). Ea, Em, Ea/Aa ratio and Em/Am ratio after hemodialysis were lower than before hemodialysis(P<0.01).Conclusions: Diastolic parameters messured by PW-TDI are affected by acute preload reduction, when the amount of change during hemodialysis is more than 2 kg.Part two: Effect of the Preload on Tissue Doppler Imaging-Tei Index Evaluating Left Ventricular FunctionObjective: To assess whether Tei index would be influenced by preload, while being used to evaluate left ventricular function.Methods: According to hemodialysis amount, thrity patients with chronic renal failure without overt heart disease were divided into two groups: group A with the hemodialysis amount less than 2kg and group B more than 2kg. They were studied using corlor pulsed wave Doppler imaging(CPWDI) and pulsed wave tissue Doppler imaging(PW-TDI) within one hour before and after hemodialysis. The Tei index of these patients were caculated with CPWDI(Tei-1) and PW-TDI(Tei-2).Results: In group A, after hemodialysis, the Tei index had no statistical difference (P>0.05). In group B, the Tei index increased signifeciantly after hemodialysis (P<0.05). Conclusions: The Tei index caculated by PW-TDI is affected by acute preload changes as well as the Tei index caculated by CPWDI, when the amount of change during hemodialysis is more than 2 kg. So it is necessary to consider the change of preload when we use Tei index to evaluate the ventricular function.