“缘对缘”二尖瓣成形术对左心室舒张功能的影响

目的探讨＂缘对缘＂二尖瓣成形术对术后左心室舒张功能的影响,以了解该成形方法的有效性及安全性。方法将2006年2月至2007年12月北京安贞医院收治的30例中至重度二尖瓣关闭不全患者,按手术方法不同分为两组,对照组：15例,二尖瓣后叶脱垂患者施行后叶楔形切除二尖瓣成形术;实验组：15例,前叶或双叶脱垂患者施行＂缘对缘＂二尖瓣成形术;所有患者均用二尖瓣成形环（Medtronic成形环）成形。用漂浮Swan-Ganz导管监测术前、术毕、术后2 h、4 h、6 h和12 h的血流动力学变化。术前和术后1周,运用脉冲多普勒、组织多普勒测定患者左心室舒张功能指标,包括术前和术后左心室舒张峰值血流速度E峰与A峰的比值（E/A）,舒张期E峰血流速度与舒张早期二尖瓣环的最大运动速度的比值（E/Em）,舒张早期二尖瓣环的最大运动速度与舒张晚期二尖瓣环的最大运动速度的比值（Em/Am）。结果两组患者二尖瓣成形二尖瓣瓣口面积均较本组术前明显减小（对照组3.63±1.06 cm2vs.7.18±2.41 cm2;实验组3.44±1.02 cm2vs.6.51±3.06 cm2;P〈0.05）,二尖瓣反流均较本组术前明显减少（对照组0.53±0.64 cm2vs.3.60±0.51 cm2;实验组0.67±0.82 cm2vs.3.40±0.63 cm2,P〈0.05）;但术前、术后两组间二尖瓣瓣口面积和二尖瓣反流比较差异无统计学意义（P〉0.05）。实验组术后E/A、E/Em和Em/Am与术前比较差异无统计学意义（E/A 1.28±0.36 vs.1.95±1.06;E/Em 8.79±2.16 vs.8.13±3.02;Em/Am 1.39±0.38 vs.1.31±0.41;P〉0.05）,两组间比较差异无统计学意义（P〉0.05）。实验组肺动脉楔压与对照组比较差异亦无统计学意义（13.60±4.37 mm Hg vs.12.20±3.53 mm Hg,P〉0.05）。结论＂缘对缘＂二尖瓣成形术效果良好,对左心室舒张功能无明显影响,双孔二尖瓣具有与正常二尖瓣相似的的血流动力学特征。     

Effects of Left Ventricular Assist Device on Cardiac Function: Experimental Study of Relationship between Pump Flow and Left Ventricular Diastolic Function

The left ventricular assist device (LVAD) with centrifugal pump has two characteristics. One is a pump flow wave of the centrifugal pump, consisting of the pulsatile flow of the native heart and the nonpulsatile flow of the centrifugal pump. The other is that the centrifugal pump fills from the native heart not only in the systolic phase, but also in the diastolic phase. In the case of the apex outlet LVAD with centrifugal pump, blood flows from the left atrium through the left ventricle to the pump. Pump flow is regulated by preload, and preload is regulated by diastolic hemodynamics. The aim of this study is to analyze the relationship between pump flow and the diastolic hemodynamics of the native heart. Ten anesthetized intact pigs were studied after placement of an LVAD. Data were recorded with the LVAD off (control) and the LVAD on. The assist rate was changed to 25%, 50%, and 75%. The indexes of left ventricular (LV) diastolic function included LV myocardial relaxation (time constant of isovolumic pressure decay [Tau] and maximum negative dP/dt [LV dP/dt min]) and LV filling (peak filling rate [PFR], time to peak filling rate [tPFR], and diastolic filling time [DFT]). Stroke volume decreased significantly in 75% assist. LV end-systolic pressure decreased significantly in 50% and 75% assist. LV end-diastolic volume decreased as assist rate increased, but there were no significant changes. Stroke work decreased significantly in 50% and 75% assist. LV dP/dt min decreased significantly in 50% and 75% assist. Tau prolonged as assist rate increased, but there were no significant changes. DFT shortened significantly in 75% assist. PFR increased significantly in 75% assist. tPFR shortened significantly in 50% and 75% assist. In this study, LV relaxation delayed as an increasing of pump assist rate, but it suggested a result of reduction of cardiac work. Also, it was suggested that LVAD increases the pressure difference between the left atrium and the left ventricle in the diastolic phase. This phenomenon is due to the filling of the left ventricle. In this study it was suggested that as pump assist rate increases, it is more effective to keep cardiac function in the diastolic phase.     

Left Atrial and Left Ventricular Diastolic Function After the Maze Procedure for Atrial Fibrillation in Mitral Valve Disease: Degenerative Versus Rheumatic

The present study was aimed to compare the left atrial and left ventricular diastolic functions amongst the rheumatic and degenerative mitral valve disease patients in atrial fibrillation who reverted to normal sinus rhythm following Cox-maze procedure. We prospectively investigated the left atrial and left ventricular function with Doppler echocardiography, by dividing into the rheumatic (N = 105) and the degenerative group (N = 47). Over the follow-up period (mean: 4.4 ± 1.2 years in the rheumatic group, 4.8 ± 1.3 years in the degenerative group), the rheumatic group showed statistically significant decrease in A'' velocity and E'' velocity, on contrary to degenerative group (A'' velocity: mean decrease of 0.43 ± 0.13 cm/s in the rheumatic group, mean increase of 0.57 ± 0.11 cm/s in the degenerative group, p = 0.029, E'' velocity: mean decrease of 0.23 ± 0.17 cm/s in the rheumatic group, mean increase of 0.21 ± 0.15 cm/s in the degenerative group, p = 0.031). In addition, the rheumatic group showed statistically significant increase in E/E'' ratio than the degenerative group (mean increase of 4.49 ± 1.98 in the rheumatic group, mean increase of 1.74 ± 1.52 in the degenerative group, p = 0.047). Despite successful sinus rhythm restoration, the progressive loss of LA function as well as LV diastolic function is more prominent in the rheumatic group than the degenerative group. Therefore, differentiated strategies for postoperative surveillance are needed according to the pathology of mitral valve disease.     

Influence of Left Ventricular Function on Changes in Plasma Volume During Acetate and Bicarbonate Dialysis

The effect of left ventricular function on changes in plasmavolume during acetate and bicarbonate dialysis was studied instable, chronic dialysis patients. Preservation of plasma volumein patients with a normal left ventricular function (mean circumferentialfibre shortening velocity (VcF) 1 circ/s) was significantlyless during the first hour of acetate dialysis than during bicarbonatedialysis. However, in patients with impaired left ventricularfunction (VcF < 1 circ/s) the decrease in plasma volume wasmore pronounced during acetate when compared to bicarbonatedialysis. This resulted in a decreased ultrafiltration volumeand haemodynamic instability in these patients during acetatedialysis. The fibre shortening velocity increased during acetateand bicarbonate dialysis in patients with a normal left ventricularfunction, whereas in patients with impaired left ventricularfunction fibre shortening velocity increased only during bicarbonatedialysis. In conclusion, in patients with an impaired left ventricularfunction, bicarbonate is preferable to acetate in chronic dialysis.     

The Prevalence of Left Ventricular Hypertrophy in Chinese Hemodialysis Patients Is Higher Than That in Peritoneal Dialysis Patients

Background. Left ventricular hypertrophy (LVH) is common in dialysis patients, and an independent predictor of mortality. While recent studies have shown no differences in mortality between the two most common dialysis modalities, hemodialysis (HD) and peritoneal dialysis (PD), their impact on LVH is controversial. We thus performed cardiac ultrasound studies in prevalent dialysis patients receiving either HD or PD and compared LVH. Methods. We included 48 HD and 62 PD patients receiving treatment for at least three months in our dialysis center. All patients underwent echocardiographic examination and blood pressure measurements immediately following therapy. Volume status was assessed by bioelectrical impedance analysis. Results. There was no baseline difference in demographics or comorbidities between HD and PD patients. As expected, extracellular water (ECW) in post-HD patients was significantly lower than that in pre-HD and PD patients, while cardiac output (CO) and systolic blood pressure (SBP) were higher in pre-HD than that in post-HD or PD patients. There was no significant difference in CO or SBP between post-HD and PD patients. Left ventricular mass index (LVMI) was markedly higher in HD patients as compared to PD patients. Thus, the prevalence of LVH according to the Framingham criteria was 68.8% in HD patients and 45.2% in PD patients. Subgroup analysis showed similar results in the patients who had been on single-modality dialysis for at least two years and in the anuric patients. Finally, in a linear regression model (r² = 0.364, p < 0.001), SBP, treatment modality (to be in HD), and ECW were all independent predictors of LVMI. Conclusions. In a cross-sectional analysis of prevalent Chinese patients, we found a higher LVMI and a higher prevalence of LVH in HD than in PD patients. As LVMI was associated with high blood pressure and volume overload, we suggest that in these patients, PD may preserve more physiological hemodynamics even during long-term therapy.     

An Association Between Inflammatory State and Left Ventricular Hypertrophy in Hemodialysis Patients

This study was performed to investigate the potential relationship between left ventricular hypertrophy (LVH) and proinflammatory cytokines in hemodialysis (HD) patients and the effect of HD on cytokine production. Serum interleukin 1 beta (IL-1 β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) measurements and echocardiographic studies were performed in 35 stable HD patients. A variety of probable risk factors for LVH including age, HD duration, blood pressure (BP), body mass index, lipid profile, hemoglobin, albumin, parathormone and homocysteine levels were also investigated. Additionally, the effect of HD procedure on cytokine levels was evaluated. Predialysis serum levels of IL-1β, IL-6, TNF-α, and homocysteine in HD patients were compared with 12 healthy subjects. Left ventricular hypertrophy was demonstrated in 20 (57%) of HD patients by echocardiography. Left ventricular mass index (LVMI) was correlated positively with systolic BP (r = 0.556, p = 0.001), diastolic BP (r = 0.474, p = 0.004), and serum levels of TNF-α (r = 0.446, p = 0.009).Multiple regression analysis showed that systolic BP and TNF-α levels were significant independent predictors of LVH. No relationship was observed between LVH and other parameters. The mean predialysis serum level of IL-6 was significantly higher in HD patients compared to healthy controls (15.7 ± 8.7 vs. 7.3 ± 0.7 pg/mL, p = 0.001). Predialysis serum levels of TNF-α in HD patients were higher when compared to healthy subjects, but the difference was not statistically significant (8.3 ± 3 vs. 7 ± 1.45 pg/mL, respectively, p > 0.05). However, serum levels of IL-6 and TNF-α significantly elevated after HD, when compared to predialysis levels (from 15.7 ± 8.7 to 17.8 ± 9.5 pg/mL, p = 0.001 and from 8.3 ± 3.0 to 9.9 ± 3.5 pg/mL p = 0.004, respectively). As a conclusion, in addition to BP, proinflammatory cytokines, TNF-α in particular, seem to be associated with LVH in ESRD patients.     

Mild Hypothermia Impairs Left Ventricular Diastolic but Not Systolic Function

Hypothermia is a component of myocardial protection during cardiopulmonary bypass (CPB) and cardioplegic arrest (CA). Patients in the early post CPB period often show mild hypothermia and cardiac dysfunction. We sought to investigate the impact of hypothermia on left ventricular (LV) function. Anesthetized dogs (n = 12) were instrumented with myocardial ultrasonic crystals and LV micromanometer. Systolic function was measured by preload recruitable stroke work (PRSW). Diastolic function was measured by ?dP/dt_max and tau. In six dogs (Norm group), body temperature was maintained at baseline levels. In another six dogs (Hypo group), body temperature dropped gradually over the time course of the experiment. The body temperature in the Hypo group decreased from 37.0 ± 0.3°C to 35.2 ± 1.0°C. ?dP/dt_max decreased and tau increased significantly with hypothermia but were stable in the Norm group. Both tau and ?dP/dt_max showed a linear relationship to the body temperature (r =.91 and r =. 93, respectively). PRSW did not change and cardiac output decreased with hypothermia. Thus, even mild hypothermia impairs LV diastolic but not systolic function. Cardiac output is temperature sensitive and therefore rewarming of patients post-CPB has priority.     

实时三维超声评价左室室壁瘤外科治疗后左心室局部收缩功能的改变

目的利用实时三维超声（real-time three-dimensional echocardiography,RT-3DE）评估左心室室壁瘤（LVA）外科治疗后左心室局部收缩功能的改变。方法 2009年2月至2010年2月,北京阜外心血管病医院连续14例冠状动脉粥样硬化性心脏病合并左心室室壁瘤形成患者（LVA组）接受手术治疗。LVA组患者术前和术后4个月随访期间均行二维超声（2DE）、RT-3DE,通过Qlab软件分析计算获得左心室局部射血分数（EF）;同时测量12例正常人的左心室局部EF作为正常对照（对照组）。利用统计方法对比分析LVA组（术前、术后4个月）与对照组左心室局部EF。结果 LVA组患者术前左心室局部EF呈心尖部至基底部递增方向,与对照组方向相反;除下基底段、下侧基底段和前侧基底段外,其余14个节段较对照组显著降低（P〈0.05）。术后4个月左心室局部EF恢复从基底部至心尖部的方向递增,前基底段和侧壁节段的EF与对照组差异无统计学意义（P〉0.05）,其余节段的EF低于对照组（P〈0.05）。结论 RT-3DE是评估LVA患者左心室局部收缩功能的有效检查方法。LVA患者手术治疗后早期左心室局部收缩功能恢复正常递增方向,部分非室壁瘤节段收缩功能恢复。     

Plasma Pentraxin 3 is Associated with Cardiovascular Disease in Hemodialysis Patients

Abstract

This cross-sectional study evaluates the associations of Pentraxin 3 (PTX3) and cardiovascular disease (CVD) in hemodialysis (HD) patients. Plasma was obtained from 98 maintenance HD patients before and after a session of HD and 50 age-matched healthy subjects. We measured plasma PTX3 levels by enzyme-linked immunosorbent assay. Our results showed that plasma PTX3 levels were significantly higher in HD patients compared with controls (1.87 vs. 1.11 ng/mL, p < 0.001), and increased acutely after a single HD session (post-HD 2.18 ng/mL vs. pre-HD 1.87 ng/mL, p < 0.001). Patients with CVD had higher plasma PTX3 levels than those without CVD (2.18 vs. 1.76 ng/mL, p < 0.05). Plasma PTX3 levels correlated positively with cardiac troponin T (ρ = 0.287, p = 0.007) and carotid artery intima-media thickness (ρ = 0.294, p = 0.043). High plasma PTX3 (>1.87 ng/mL) level was positively and independently associated with CVD (OR = 3.15, p = 0.024). Receiver operator characteristics analysis showed the correlation between PTX3 and CVD more closely than high sensitivity C-reactive protein (hs-CRP) in patients whose hs-CRP were higher than 3 mg/L. The area under the curve for PTX3 and hs-CRP was 0.655 (p = 0.047) and 0.562 (p = 0.458), respectively. Moreover, plasma PTX3 levels correlated negatively with body mass index, hemoglobin, pre-albumin, total cholesterol, triglyceride, and low-density lipoprotein. These data support the main conclusions: PTX3 levels are markedly elevated in HD patients; HD procedure itself induces PTX3 elevation; plasma PTX3 is associated with CVD in maintenance HD patients.     

无支架异种生物瓣膜主动脉瓣替换术后左室功能变化

评价无支架异种生物瓣膜主动脉瓣替换术后２年左室功能的变化。将８０例同期施行主动脉瓣替换病人分为２组，５０例（年龄６９．３±９．３岁）应用ＴｏｒｏｎｔｏＳＰＶＴＭ瓣；３０例（年龄７１．６±７．７岁）作为对照组接受支架人工瓣膜替换。术前、术后１、６、１２及２４个月间记录Ｍ型及Ｄｏｐｐｌｅｒ超声心动图，采用计算机图像数字分析，定量测定左室功能的变化。随访期间，Ｔｏｒｏｎｔｏ组主动脉瓣跨瓣压差为０．８±０．６ｋＰａ（６．０±４．５ｍｍＨｇ），明显低于对照组２．３±０．９ｋＰａ（１７．３±６．８ｍｍＨｇ）；术后１个月，左室心肌质量下降２５％，左室＋Ｖｃｆ及－Ｖｃｆ明显增加（２．０±０．８／１．４±０．３ｓ－１，Ｐ＜０．０１；２．８±１．２／１．８±０．７ｓ－１，Ｐ＜０．０１）。术后６个月，左室功能进一步改善，心室肥厚的消退更趋完全，该变化在其后的随访期间保持稳定。结论：与支架瓣膜相比，无支架异种生物瓣膜具有较大瓣口开放面积及低跨瓣压差，这促进了术后左室功能的恢复及病理性肥厚的逆转     

Relation between Pulmonary Function and Inflammatory Biomarkers in Hemodialysis Patients

The purpose of our study was to investigate the relationship between pulmonary function and serum levels of C-reactive protein (CRP), ferritin, albumin, and erythrocyte sedimentation rate, as inflammatory biomarkers, in hemodialysis patients. Ninety-eight patients, who were dialyzed at least for 3 months, were included in this study. Patients’ blood samples were collected and pulmonary function tests, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and peak expiratory flow (PEF) were measured and expressed as the %predicted using appropriate normal values for the patients’ sex, age, and height (%FVC, %FEV1, and %PEF), at the same time. The patients with CRP ≥ 10 μg/mL were significantly older and had lower values of %FEV1, %FVC and %PEF (p = 0.006, p = 0.001, and p = 0.016, respectively); whereas just %FEV1 (p = 0.025) and %FVC (p = 0.009) had significant differences between the patients with ferritin ≥ 100 μg/L and other patients. However, no other significant differences were found between inflammatory biomarkers and the pulmonary function tests. We concluded that inflammation has a close relation with pulmonary dysfunction in hemodialysis patients.     

Preserved Residual Kidney Function after Twelve Years' Hemodialysis

Residual kidney function (RKF) contributes significantly to solute clearance and fluid removal for dialysis patients, and the presence of RKF is associated with less morbidity and better long-term outcome. Most studies demonstrate that peritoneal dialysis preserves RKF better than hemodialysis (HD). Herein, we report a 55-year-old man with end stage renal failure who had been on chronic HD for 12 years. His RKF is preserved with very slow decline during the past years. Without specific intervention, delicate fluid management, minimal ultrafiltration, and stable hemodynamics during HD may help maintain his RKF. He is currently normotensive with good nutritional status. Although unexpected, we report this HD patient can preserve his RKF for at least 12 years.     

维持性血液透析患者钙磷代谢及透析龄与左心室心肌质量指数的关系

目的:探讨维持性血液透析患者钙磷代谢及透析龄与左心室心肌质量指数的关系。方法:研究对象为上海市第六人民医院血液透析中心接受维持性血液治疗1年以上的102例患者,按血磷分为高磷组(Pi>1.78 mmol/L,n=72)和对照组(Pi:1.13 mmol/L~1.78 mmol/L,n=30);按钙磷乘积分为对照组(钙磷乘积≤55 mg2/dl2,n=47)和高钙磷乘积组(钙磷乘积>55 mg2/dl2,n=55);按透析龄分为A组(透析龄1~5年,n=61)和B组(透析龄>5年,n=41)。用超声心动图测定左心室舒张末内径(LVDd)、左心室收缩末内径(LVDs)、左房内径(LAD)、左心室后壁厚度(LVPWT)、室间隔厚度(IVST),并收集临床指标。结果:(1)将血磷、钙磷乘积及透析龄与反应心脏结构的指标(LVDd、LVDs、LAD、IVST、LVPWT、LVMI)进行相关性分析,结果发现维持性血液透析患者心脏结构的改变与钙磷代谢及透析龄密切相关。另外,钙磷乘积和透析龄与FS存在相关性。(2)高磷组LVDd、LVDs及LVMI与对照组比较,其差异均有统计学意义(P<0.05),说明高磷血症患者出现左心室肥大。(3)高钙磷乘积组的LVDd、LVDs及LVMI与对照组比较,其差异均有统计学意义(P<0.05),说明钙磷乘积升高组,左心室肥大较对照组显著。(4)两组患者比较LVH发生比率,结果显示,B组要高于A组(71.89%vs37.78%,P=0.045),差异有统计学意义。A组LVDd、LVDs、LVPWT、LVMI及FS与B组比较,其差异均有统计学意义(P<0.05),说明随着透析时间的增长,心脏结构的改变越来越明显,左心室肥大的发生率越来越高。结论:维持性血液透析患者普遍存在心脏结构的改变,随着透析龄的增加,心脏结构和功能进一步恶化。钙磷代谢及透析龄影响心脏结构改变,最终导致心功能衰竭。     

Underuse of American College of Cardiology/American Heart Association Guidelines in Hemodialysis Patients

Patients with end-stage renal disease (ESRD) are at high risk for cardiovascular disease (CVD) and therefore should be treated according to ACC/AHA Guidelines. Scant data are available concerning the actual use of cardioprotective drugs in this population. The use of angiotensin-converting enzyme inhibitors (ACE-I), β-blockers, aspirin, and statins was assessed in 271 (72% males, 66% Caucasians) high-risk ESRD patients on hemodialysis. The study population comprised 27% smokers, 95% with hypertension, 38% with diabetes, and 44% with dyslipidemia; 44% of patients had overt CVD at baseline, including 9% with heart failure, 9% with prior myocardial infarction, and 3% with previous myocardial revascularization. One-third of all patients were not receiving any cardioprotective drugs; among those patients who were, 42% were on one drug, 21% were on two, 3.7% were on three, and 1.5% were on four. The most prescribed agent was ACE-I (35.8%), followed by aspirin (30.6%), and β-blockers (28.0%). The use of statins was remarkably and significantly low (4.1%) (p < 0.001), even in the higher risk subgroups (patients with diabetes or macrovascular disease). ACE-I plus aspirin was the most prescribed combination (8.5%). Cardioprotective agents recommended for risk-factor modification by the ACC/AHA Guidelines for their well-established efficacy in the general population were underutilized in this cohort of high-risk hypertensive hemodialysis patients, despite an elevated prevalence of clinically evident CVD. Speculatively, this fact may be relevant to better understand the known increased cardiovascular morbidity-mortality associated with chronic renal disease.