Evaluate The Effects Of A Single Hemodialysis Session On Left Cardiac Mechanics And Function In Patients With End-stage Renal Disease By Speckle Tracking Imaging And Vector Flow Mapping

BackgroundCardiovascular diseases account for more than half of the death in patients with chronic kidney disease.Causes of mortality rates include arrhythmia,heart failure and ischemic heart disease.The causes of these cardiovascular abnormalities include:anemia,fluid retention,chronic volume and pressure overload,uremia,high-flow arteriovenous shunting,abnormal calcium and phosphorus metabolism,and hyperparathyroidism.In addition,dialysis treatment can also stress cardiovascular system because of acute changes in blood volume,blood pressure,electrolytes,and sympathovagal balance.Transthoracic echocardiography is the most commonly used imaging modality to evaluate cardiac function.Many conventional parameters used to evaluate left ventricular systolic and diastolic function have been shown to be load-dependent,but there are also many contradictions.In hemodialysis patients,the pre-and post-load status changes a lot before and after dialysis.Our study combined conventional echocardiographic parameters,two-dimensional speckle tracking and vector flow mapping(VFM)to comprehensively evaluate the extent which the left ventricle and left atrium were affected by dialysis treatment.The VFM technology can evaluate the fluid dynamics in the heart cavity,such as circulation,energy loss,and ventricular wall shear stress.Two-dimensional speckle tracking echocardiography(STE)can evaluate the deformation of ventricular muscle in multiple directions,such as longitudinal,circumferential and radial directions.In the present study,the effects of hemodialysis-induced preload reduction on left ventricule and left atrium function were determined in patients undergoing long-term hemodialysis by echocardiography,including pulsed Doppler,tissue Doppler,STE and VFM.Part ? Changes in left ventricular and atrial mechanics and function after dialysis in patients with end-stage renal diseaseObjectivesHemodialysis(HD)can influence end-stage renal disease(ESRD)patients'circulatory system.The present study aimed to evaluate the effect of volume depletion on left ventricular(LV)and left atrial(LA)function and determine the volume-independent parameters before and after HD in patients with ESRD.MethodsBetween January 2018 and January 2019,we recruited long-term HD patients(n=40,51.0 ± 16.4 years),excluding those with structural cardiac disease.Echocardiographic parameters,including LV and LA volumes,flow Doppler,pulsed tissue Doppler,and STE before and after HD(within 24 h),were examined,and the values were compared.ResultsFollowing HD,alteration in LV end-systolic volume was not detected,whereas LV end-diastolic volume(90.18±23.91 vs.84.21±23.54 mL,P=0.036)and LV ejection fraction(LVEF;64.63%±6.56%vs.62.84%±6.56%,P=0.049)decreased.Peak early diastolic trans-mitral flow velocity(E-wave;82.22±20.13 vs.72.43±18.32 cm/s,P<0.001),peak early diastolic tissue Doppler velocity(e';6.45±1.88 vs.5.77±1.63 cm/s,P<0.001)at the septal side of the mitral annulus,the ratio of early to late Doppler velocities of diastolic mitral inflow(0.90±0.27 vs.0.79±0.23,P<0.001),and the average E/e' ratio(12.54±4.08 vs.11.28±4.52,P=0.049)decreased significantly.No significant difference was found in peak blood flow velocity at the mitral valve during late diastole and e'at the lateral side of the mitral annulus after HD.LA volume index(35.55±12.61 vs.30.22±9.80 mL/m2,P<0.001),tricuspid regurgitation velocity(260.11±36.54 vs.242.37132.22 cm/s,P=0.002),and pulmonary artery systolic pressure(33.63±11.29 vs.29.94±7.80 mmHg,P=0.006)significantly decreased.LV global longitudinal systolic strain(GLS)of 4-chamber view(-24.37%±3.02%vs.-23.38%±3.33%,P=0.019),rather than global circumferential systolic strain,exhibited significant change after HD.Significant changes were also found in LV longitudinal early diastolic strain rate(LSRe;1.17±0.25 vs.1.05±0.24 s-1,P<0.001)and early diastolic global radial velocity(Ve;2.62±0.59 vs.2.25±0.67 cm/s,P=0.011)after HD,but not in other strain rates and global radial velocity measurements.LA maximal volume(35.55±12.61 vs.30.22±9.80 mL/m2,P<0.001),LA total emptying fraction(54.19%±10.39%vs.49.63%± 11.05%,P=0.009),and LA passive emptying fraction(32.23%± 12.86%vs.26.81%±9.28%,P=0.004)decreased significantly after HD,while LA minimal volume,the volume at the onset of atrial systole,and LA active emptying fraction after HD were not significantly different.ConclusionsMost indices of systolic(LVEF and GLS of 4-chamber view)and early diastolic function(E-wave,e',LSRe,radial Ve,and LA passive emptying fraction)were different before and after HD.Late diastolic indices,including LV late diastolic global longitudinal strain rate,late diastolic global radial velocity,and LA active emptying fraction,did not change following HD.Part ? The effects of a single hemodialysis session on left ventricular energy loss and wall shear stress assessed by vector flow mappingObjectivesThe purpose of the study was to evaluate the changes of left ventricular summation of energy loss(EL-SUM),average energy loss(EL-AVE)and wall shear stress(WSS)before and after HD using VFM in ESRD patients.MethodsWe recruited long-term HD patients(n=40,51.0±16.4 years),excluding those with structural cardiac disease.Echocardiography was performed before and within 24 hours after HD.Conventional echocardiographic parameters,summation and average energy loss(EL-SUM,EL-AVE,EL-base,EL-mid and EL-apex)WSS in each segment were calculated at different phases pre-and post-HD,and the values were compared.ResultsAfter HD,left ventricular EL-AVE-total and EL-SUM-total decreased significantly in the early diastole(P<0.001 and P<0.001,respectively),mid-diastole(P=0.005 and P=0.002,respectively)and early systole(P=0.018 and P=0.008,respectively)phases.HD didn't change EL-AVE-total and EL-SUM-total parameters in late diastole and late systole periods.Segment analysis showed that decrease of EL-AVE was observed after HD in LV basal segment during the early diastole(P=0.012);in LV basal(P=0.017),mid(P=0.001)and apical(P=0.017)segments during mid-diastole as well as in basal(P=0.046)and apical(P=0.046)segments during early systole period.WSS significantly reduced in the mid-diastole(0.50±0.23 vs.0.40±0.18 Pa,P<0.001)and early systole(0.66±0.32 vs.0.58±0.25 Pa,P=0.015)periods after HD.There were no significant changes in WSS during the early diastole,late diastole and late systole periods.ConclusionsEL and WSS of LV decreased during systolic and diastolic phases after HD.VFM can effectively assess LV hemodynamic status of HD patients with different fluid loading status.