心肌肌钙蛋白Ⅰ在体外循环心内直视手术中对心肌损伤的监测作用

目的　探讨心肌肌钙蛋白Ⅰ (cTnⅠ )对先心病心内直视手术围体外循环期心肌缺血再灌注损伤的监测价值。方法　选择 2 0例拟行房或室间隔缺损修补术的先心病病人 ,随机分为对照组 (C组 )与乌司他丁组 (U组 ) ,每组 10例。分别于围术期多个时点采取桡动脉血 ,测定血浆肌钙蛋白Ⅰ (cTnⅠ )、肌酸激酶 (CK)及同工酶 (CK MB)浓度。结果　两组病人术前血浆cTnⅠ、CK和CK MB浓度均在正常范围内 ,且组间比较无差异。C组血浆cTnⅠ浓度在T3 、T4和T5时点都有显著升高 (P <0 0 0 1) ,于T4时点达峰值 ,T5时点开始下降。U组血浆cTnⅠ浓度在T3 、T4时点明显升高(P <0 0 0 1) ,于T5时点已下降至正常水平 ;在T3 、T4及T5时点U组cTnⅠ明显低于C组 (P <0 0 5 )。C组与U组血浆CK和CK MB浓度 ,在T2 、T3 、T4和T5时点都明显升高 (P <0 0 0 1) ,T2 、T3 及T4时点两组比较无显著性差异 ,至T5时点U组显著低于C组 (P <0 0 5 )。结论　cTnⅠ作为心肌损伤标志物 ,与CK、CK MB比较敏感性和特异性更高 ,是心内直视手术围术期检测心肌损伤的可靠指标。     

逆行灌注心脏不停跳法对犬心肌的保护作用

目的　探讨逆行灌注心脏不停跳法对体外循环术中心肌的保护作用。方法　将 16条健康杂种犬随机分成心脏不停跳组 (A组 )和心停搏液组 (B组 ) ,每组 8条。体外循环 15 0min ,经冠状静脉窦连续逆行灌注氧合机器血或间断灌注冷血心停搏液 12 0min。于 6个时点采颈静脉和冠脉血检测心钠素 (ANP)、降钙素基因相关肽 (CGRP)、内皮素 (ET 1)和肌钙蛋白 (cTn T)。结果　逆行灌注 60、90、12 0min、开放上下腔静脉 3 0min和术毕时 ,各项生化指标均比体外循环前显著增高 (P <0 .0 5 ) ,但A组的ANP、CGRP均较B组高 (P <0 .0 5 ) ,ET 1和cTn T均比B组为低(P <0 .0 5 ) ,且血流动力学平稳。B组有 6条犬需除颤复跳 ,3条犬出现频发室性早搏 ;全组需用多巴胺 5～ 10 μg·kg-1·min-1才能维持血流动力学平稳。结论　逆行灌注心脏不停跳法有利于调动内源性ANP、CGRP等活性物质拮抗ET的有害作用 ,心肌保护效果较好。     

左心辅助对犬缺血右心室的影响

目的　观察左心辅助对缺血右心室的影响。方法　 2 0条健康犬按不同左心辅助流量随机分为 4组 :Ⅰ组 :对照组 ;Ⅱ组 :辅助流量为 5 0ml·kg-1·min-1;Ⅲ组 :辅助流量为 70ml·kg-1·min-1;Ⅳ组 :辅助流量为 90ml·kg-1·min-1。结扎右冠状动脉 8min ,应用气动左心辅助装置行左心房至升主动脉辅助 3h。观察右心血流动力学及右心室心肌ATP、心肌超微结构的变化。结果　与对照组相比 ,阻断右冠状动脉近端 (RCA)前 ,Ⅱ、Ⅲ、Ⅳ组各项动力学指标差异均无显著性 (P >0 .0 5 ) ,阻断RCA 8min ,Ⅱ、Ⅲ组右心室最大压力上升速率 (Rvdp/dtmax)减小 (P <0 .0 5 ) ,全肺阻力(TPR)降低 (P <0 .0 5 ) ,右心排血量 (RCI)及ATP含量差异无显著性 (P >0 .0 5 ) ,心肌超微结构的变化大致相似。Ⅳ组Rvdp/dtmax减小 ,TPR升高 ,RCI减少 ,ATP含量降低 (P值均 <0 .0 1) ,心肌超微结构病变加重。结论　高流量左心辅助导致缺血右心室的功能恶化衰竭。     

心衰后胶原网架结构变化与左旋精氨酸保护作用的实验研究

目的：观察急性左心衰后心肌胶原网架结构的变化及左旋精氨酸（ＬＡｒｇ）对心肌细胞及间质的保护作用，进一步探讨心衰机制及围手术期心肌保护方法。方法：１６只犬随机均分为两组，通过心肌缺血再灌注损伤法制造急性左心衰模型，离心泵行左心辅助１２０分，辅助期间实验组加ＬＡｒｇ３００ｍｇ／ｋｇ，分别观察两组血流动力学、心肌超微结构、血浆ＥＴ１。结果：实验组在辅助循环期间室颤发生率及死亡率较低，生存时间长于对照组，ＥＴ１心衰后明显高于心衰前，辅助后实验组有所下降。心肌超微结构实验组优于对照组。结论：心肌胶原网架在急性心衰过程中起着重要作用，ＬＡｒｇ对急性缺血心肌及间质有保护作用。     

气动泵的不同流量对急性左心衰竭辅助作用的实验研究

目的 用血液动力学、心肌超微结构及神经体液指标评价左室辅助装置（ＬＶＡＤ）的有效性。方法 ,对２０条急笥左心衰犬进行高,中、低流量的１８０ｍｉｎ左室辅助,观察其对上述指标的影响。结果 ＬＶＡＤ可使急性左心衰犬各项血流动力学指标迅速趋于稳定,血浆肾素,血管紧张素Ⅱ,内皮素下降,一氧化氮升高,与心力衰竭时差异有显著意义;使心肌细胞水肿和线粒体肿胀减轻。结论 不同辅助流量对急性左心衰时支持均有效,但以中     

B-型利钠肽、左室射血分数、6分钟步行实验评价心力衰竭患者心功能的临床价值

目的:探讨慢性心力衰竭(CHF)患者通过血浆B-型刺钠肽水平、左室射血分数、6分钟步行实验综合评价心功能的临床价值.方法:采用心力衰竭诊断仪测定心衰患者血浆BNP水平,同时采用NYHA心功能分级和超声心动图评价患者左心功能,记录6分钟步行实验距离,并对结果进行相关性分析.结果:1.CHF组与对照组患者血浆BNP水平比较及其与心功能分级的关系:CHF组各亚组的BNP水平与对照组比较,有显著性差异(P<0.01).CHF组组间两两比较BNP水平,有显著性差异(P<0.01),并随着心功能分级的增加和心功能的恶化,水平逐渐增加,二者呈正相关(r=0.708,P<0.01).2.BNP水平与左室射血分数呈负相关(r=-0.992),与6分钟步行实验距离呈负相关(r=-0.756),左室射血分数与6分钟步行试验距离呈正相关(r=0.989).结论:测定血浆BNP水平,结合NYHA心功能分级、起声心动图左室射血分数、6分钟步行试验有助于对心力衰竭患者的心功能进行综合评估.     

脑利钠肽在评价功能性单心室患者TCPC后心功能中的价值及意义

目的探讨脑利钠肽(BNP)在评价功能性单心室患者行全腔静脉-肺动脉连接术(TCPC)后心功能中的价值及其意义。方法选择2004年4~11月间连续在我科随访的TCPC后患者11例(TCPC组),男7例,女4例;年龄8.2±4.1岁;随访时间2.1±1.6年。按照改良R oss标准对临床心功能评分。采集外周静脉血3m l,用酶标免疫法测定血浆BNP浓度。其中6例同期用磁共振成像(M R I)测定心功能,对BNP做相关因素分析。9人健康儿童作为正常对照(对照组)。结果(1)TCPC组血浆BNP水平为400pg/m l(IQR 200-690),较对照组的110 pg/m l(IQR 90-190)增高(P=0.003);(2)M R I测定结果:TCPC组6例患者舒张期末容量指数为65.76±8.65 m l/m2,收缩期末容量指数为31.90±6.36 m l/m2,心搏出量指数为39.09±11.76 m l/m2,射血分数(EF)为0.52±0.06,心脏指数(C I)为2.38±0.58 L/m in.m2,心肌质量指数为103.49±21.57 g/m2,心肌质量/心室舒张期末容量为1.57±0.24;(3)TCPC组BNP水平与手术时年龄呈明显正相关(r=0.632,P=0.041);BNP水平与上述M R I指标、R oss评分、性别、年龄、脉搏血氧饱和度(SpO2)及主心室类型等因素无关。结论TCPC后近2年神经内分泌系统仍处于应激状态,BNP增高可能与TCPC后特有的血流动力学状态有关;血浆BNP水平不能作为正确评估TCPC后心功能状态的指标。     

气动泵对急性左侧心力衰竭辅助时神经体液因子的影响

目的　探讨气动泵对急性左侧心力衰竭不同流量辅助时内皮素、一氧化氮、血浆肾素、血管紧张素Ⅱ的影响。　方法　对２０ 条急性左侧心力衰竭犬随机分成４ 组：Ⅰ组：低流量辅助（５０ｍｌ／ｋｇ·ｍｉｎ） ；Ⅱ组：中流量辅助（７０ ｍｌ／ｋｇ·ｍｉｎ） ；Ⅲ组：高流量辅助（９０ｍｌ／ｋｇ·ｍｉｎ） ；Ⅳ组：对照组。对４ 组分别进行高、中、低流量的１８０ 分钟左心室辅助，观察其对血流动力学和神经体液因子的影响。　结果　左心室辅助循环可使急性左侧心力衰竭犬肺毛细血管嵌压、血浆肾素、血管紧张素Ⅱ、内皮素迅速下降，平均主动脉压、心脏指数、左心室做功指数、一氧化氮均升高（ Ｐ＜ ０－０５） 。　结论　不同辅助流量对急性左侧心力衰竭时左心功能支持均有效，但以中、高流量效果最佳。     

常温下缺血心肌组织pH的变化能反映其细胞代谢

为了阐明常温下缺血心肌组织pH的变化与心肌细胞内pH和生物能之间的关系,作者选择体重20～22kg的健康犬14条,全麻后进胸显露心脏,持续监测心肌温度,MAP、LVEDP、HR、dp/dt max、心肌组织pH(壁内电极法)、心肌细胞pH(31~p-NMR法)及ATP并记录.然后将犬分成2组,组Ⅰ(n=7)为实验组,分离并阻断左冠状动脉前降支(LAD),使该动脉灌注区完全缺血,再重复监测上述参数,持续3hr.组Ⅱ(n=7)为对照组,除不阻断LAD外,余均同组Ⅰ.结果:两组犬的心肌温度均保持在36℃.两组血流动力学参数(MAP、dp/dt max、LVEDP等)在实验期间均无明显变化,组Ⅰ的心肌组织pH值自LAD阻断前的7.38±0.02降至阻断3hr后的5.90±0.13,与组     

左心室辅助装置对缺血心肌功能恢复的影响

本研究旨在观察急性心肌缺血后行左心室辅助装置 (ＬＶＡＤ)辅助循环15 0ｍｉｎ期间内血流动力学、心肌能量物质代谢和心肌超微结构的变化 ,探讨ＬＶＡＤ促进心肌功能恢复的机理。一、材料和方法1.实验动物和分组 :成年绵羊 18头 ,平均体重 41.5ｋｇ ,随机分为ＬＶＡＤ和对照组 ,每组 9头。2 .麻醉及监测 :静脉麻醉插管后 ,接呼吸机控制呼吸。左股动脉插管测定动脉平均压 ,并分别插管测定左、右心房及左、右心室压力。3.ＬＶＡＤ的实施方法及缺血心肌模型制作 :降主动脉置入 2 2Ｆ的动脉供血管 ,左心耳置入 32Ｆ的动脉回血管 ,分别与气动隔…     

The time course of natriuretic hormones as plasma markers of myocardial recovery in heart transplant candidates during ventricular assist device support reveals differences among device types.

BACKGROUND: The natriuretic hormones ANP and BNP are expressed differently in the myocardium. Both hormones have compensatory diuretic activity during heart failure. Mechanical stretch of the myocardial walls induces the expression of these hormones. In failing human myocardium, both ANP and BNP are transcribed in the ventricular myocardium in high amounts. We measured the plasma concentrations of ANP and BNP in patients supported by various ventricular assist devices (VADs) at various times. We analyzed the time courses of ANP and BNP to determine (1) the time scale of their down-regulation as a marker of putative myocardial recovery, (2) their steady-state levels under VAD support and (3) differences caused by various VAD devices. METHODS: We analyzed ANP and BNP using commercially available radioimmune assays. We analyzed the time courses of patients supported by Thoratec (THO) LVAD (n = 8), TCI Heartmate (TCI) (n = 6), Novacor (NOV) (n = 7), and Lionheart (LIO) (n = 3). RESULTS: Patients supported with NOV and some patients with TCI showed down-regulation of BNP to a steady-state level at 30 to 50 days, following a single exponential decay. In contrast, patients supported by THO or LIO did not reveal a determined time course of the natriuretic hormones. Only a few patients reached normal plasma values during VAD support. CONCLUSION: The time courses of ANP and BNP differ among VAD types because of construction and/or driving mode, which might be important when considering patients for weaning from VAD without heart transplant.     

Plasma neurohormone levels correlate with left ventricular functional and morphological improvement in LVAD patients

OBJECTIVE: Brain natriuretic peptide (BNP) and endothelin-1 (ET-1) have been shown to be markers of left ventricular (LV) function. To determine the feasibility of using serial assays of these neurohormones in the assessment of cardiac status in the left ventricular assist device (LVAD) setting, we examined the relationship between LV function, myocardial morphology, and plasma levels of these hormones in LVAD recipients. METHODS: Plasma BNP and ET-1 levels were serially assayed in 19 end-stage congestive heart failure (CHF) patients before and after LVAD implantation with various devices (i.e., MicroMed DeBakeyVAD/DVAD, Novacor/NVAD, TCI Heartmate/TCI, Thoratec/TVAD). Echocardiography performed correspondingly at the time points of the hormonal assays and immunohistochemical collagen staining of left ventricular tissue samples, derived from six non-failing hearts as well as from LVAD patients at the time of device insertion and removal, were then contrasted. Patients were grouped according to device used and etiology of heart disease (ischemic or dilated cardiomyopathy, ICM/DCM). RESULTS: LVAD therapy significantly improved LV ejection fraction (EF%: 21 +/- 3.8% to 28.11 +/- 3.57%), cardiac output (CO: 3.49 +/- 1.3 to 7.3 +/- 0.2 l/m), and left ventricular end-diastolic diameter (LVEDD: 6.68 +/- 0.92 versus 4.79 +/- 1.54 cm, P < 0.0001) in all patients. Absolute BNP and ET-1 plasma levels remained significantly lower in all patients after LVAD implantation (both P < 0.001). The NVAD group exhibited the most BNP reduction and EF% increase (P < 0.0004 and P < 0.038, respectively). Average collagen levels were reduced in all patients (P < 0.0005). Among the devices, the NVAD group demonstrated the most evident change (P < 0.0036), while there was comparable reduction in the DCM and ICM groups (both P < 0.03). In general, postoperative BNP and ET-1 trends exhibited a notable parallelism with both manifesting bi-phasic tendencies and an inverse proportionality to corresponding EF% measurements. CONCLUSIONS: Device selection appears to influence the cardiac morphological and neurohormonal expressive tendencies exhibited by recipients. Plasma BNP and ET-1 levels correlate with both LV function and myocardial morphological improvement. Alterations in the levels of these hormones during LVAD support may be real-time indicators of prevailing myocardial autocrine/paracrine activity and as such may be of potential use in future algorithms of cardiac assessment and therapeutic decision-making with regard to transplant urgency and/or possible device explantation.     

Comparison of plasma levels of mature adrenomedullin and natriuretic peptide as markers of cardiac function in hemodialysis patients with coronary artery disease

BACKGROUND: It has been suggested that, like ANP and BNP, high plasma levels of mature adrenomedullin (mAM) indirectly reflect the severity of heart failure or renal failure. However, the relationship between mAM levels and hemodynamics and cardiac function has not been examined in hemodialysis (HD) patients with coronary artery disease (CAD). The best marker, among mAM, ANP and BNP, for left-ventricular function in those patients is also unclear. PATIENTS AND METHODS: Plasma levels of mAM, total AM (tAM), ANP and BNP were determined before HD in chronic HD patients with CAD (group 1; n = 17) and were compared with those of HD patients without cardiac disease (group 2; n = 22). We examined their relationship to hemodynamics and cardiac function in group 1 using data obtained by cardiac catheterization. RESULTS: Plasma levels of ANP and BNP were significantly higher in group 1 than in group 2, but there was no significant difference in plasma levels of mAM and tAM between the two patient groups. Plasma levels of both mAM and tAM significantly correlated with right atrial pressure (RAP), and only plasma tAM levels correlated with pulmonary artery pressure (PAP) and pulmonary artery wedge pressure (PAWP). However, no correlations were found between levels of the two forms of AM and ejection fraction (EF). In contrast, plasma ANP and BNP levels significantly correlated with both PAP and PAWP, and also with EF, although they did not correlate with RAP. The correlation of PAP and PAWP with ANP and BNP levels was closer than that with tAM levels. The most significant correlation was between BNP levels and EF (r = -0.756, p < 0.0001). CONCLUSIONS: Our results suggest that the mAM level may be less useful than natriuretic peptide levels as a marker of cardiac function in HD patients with CAD, and that the BNP level might be the best indicator of left-ventricular function. In addition, cardiac disease such as CAD may have a minor impact on mAM levels compared to renal failure.     

非体外循环冠状动脉旁路移植术后早期血流动力学和心肌损伤的观察

目的观察非体外循环冠状动脉旁路移植术（OPCAB）后早期血流动力学变化及心肌损伤。方法选择20例择期OPCAB患者,连续监测血流动力学变化,并记录麻醉诱导后10min（T0）、血运重建后30min（T1）、2h（T2）、6h（T3）、12h（T4）、24h（T5）的血流动力学参数,同时测定血浆肌酸激酶同功酶（CK-MB）、心肌肌钙蛋白1（cTnI）和N端B型脑钠肽（NT—proBNP）浓度。吻合血管前和血运重建后30min分别取右心房心肌组织透射电镜观察超微结构的变化。结果围术期SBP和DBP无明显变化,但血运重建后HR增快（P〈0．01）、CVP、肺动脉楔压（PCWP）、平均肺动脉压（MPAP）和心指数（cI）升高（P〈0．01）,而体循环阻力（SVR）、体循环阻力指数（SVRI）、每搏数（SV）、每搏指数（SVI）和左室每搏功指数（LVSWI）降低,右室每搏功指数（RVSWI）仅在血运重建后2h降低（P〈0．01）。CK-MB和cTnI从血运重建后持续升高（P〈0．05）,尤以血运重建后24h为明显。NT-proBNP在血运重建后12h内无显著变化,但在血运重建后24h显著升高（P〈0．01）。透射电镜下见血运重建后肌丝结构较术前模糊,线粒体有变形,结构不清晰,嵴模糊。结论OPCAB血运重建后早期存在心肌损伤和左右心功能下降,以左心为著。     

Improved Cardiac Function in Patients With Obstructive Jaundice After Internal Biliary Drainage: Hemodynamic and Hormonal Assessment

OBJECTIVE: To investigate myocardial function in patients with obstructive jaundice before and after internal biliary drainage. SUMMARY BACKGROUND DATA: Increased plasma levels of atrial natriuretic peptide (ANP) have been found in patients with biliary obstruction. METHODS: Thirteen patients with newly diagnosed obstructive jaundice and no previous heart, lung, or renal disease were studied using a Swan-Ganz catheter. Hemodynamic measurements were taken before and 4 days after internal biliary drainage. Levels of ANP and brain natriuretic peptide (BNP) were obtained and liver function tests were also determined. RESULTS: Plasma levels of ANP and BNP were increased twofold to fourfold in the basal state and declined after biliary drainage. Independent variables predicting left ventricular systolic work were total bilirubin concentrations, duration of jaundice, and BNP. In addition, bilirubin concentrations correlated with pulmonary vascular resistance, mean arterial pulmonary pressure, and right ventricular systolic work. Internal biliary drainage resulted in an improvement in left ventricular systolic work. A correlation was found between decreasing ANP concentrations and increasing cardiac output. CONCLUSIONS: Increased plasma levels of natriuretic peptides in patients with obstructive jaundice may reflect a subclinical myocardial dysfunction correlating with the degree of jaundice. After internal biliary drainage, there is a measurable improvement of cardiac function.     

Correlation between plasma neurohormone levels and left ventricular functional and morphological improvement in LVAD patients

Objective: Certain neurohormones (e.g., brain natriuretic peptide (BNP), endothelin-1 (ET-1)) have demonstrated reliability as clinical markers of left ventricular (LV) function. The aim of this study was to examine the relationship between plasma levels of these neurohormones, LV function and histological evidence of morphological improvement in left ventricular assist device (LVAD) recipients to determine whether serial hormonal expression may be used to assess cardiac status in the LVAD setting. Methods: Plasma levels of BNP and ET-1 were measured in 19 end-stage congestive heart failure patients directly before and up to 18 weeks after implantation with various devices (DeBakeyVAD, Novacor, TCI HeartMate). Echocardiographic indices corresponding to the time-points of serial hormonal measurement were evaluated. Immunohistochemical collagen staining of LV tissue samples derived from LVAD patients at the time of device insertion and removal were then contrasted. Patients were grouped according to device employed and etiology (ischemic/dilated cardiomyopathy, ICMP/DCMP). Results: LVAD therapy significantly enhanced LV ejection fraction (EF%: 21% ± 3.8% to 37% ± 11.39%) and cardiac output (CO: 3.49 ± 1.3 to 7.3 ± 0.2 l/m) in all patients; other parameters were not appreciably altered. Absolute BNP and ET-1 plasma levels remained significantly lower in all patients after LVAD implantation (both: p < 0.001). The NOV group exhibited the most BNP reduction and EF% increase (p < 0.0004 and p < 0.038, respectively), whereas ET-1 was lower in the DVAD group (p < 0.06). In all categories, the ICMP group experienced more significant change when compared to those in the DCMP grouping. Collagen levels were sharply reduced in all patients (p < 0.0005); however, while those in the DVAD demonstrated the most evident change (p < 0.0036), there was little difference between the DCMP/ICMP groups (p < 0.012 vs p < 0.022). Both BNP and ET-1 manifested bi-phasic tendencies and an inverse proportionality to EF% measurements. Conclusions: Plasma BNP and ET-1 levels appear to correlate both with device-related LV functional and myocardial morphological improvement and may be of potential use as therapeutic indicators.     

Vasoactive peptides during long-term follow-up of patients after cardiac transplantation.

BACKGROUND: Vasoactive peptides are accepted indicators of the degree of heart failure and its progression or improvement following medical therapy. Normalization of cardiac hemodynamics by cardiac transplantation (HTx) may lead to normalization of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) plasma levels shortly after the procedure. METHODS: Long-term follow-up was done for 14 consecutive patients, 12 men and 2 women, 49 years of age (range 24 to 64 years). ANP and BNP were measured by radioimmunoassay (RIA) in central venous plasma samples (before breakfast, at steady state) at the following intervals after HTx: 7 to 30 (1), 31 to 60 (2), 61 to 90 (3), 120 to 180 (4) and 210 to 365 (5) days. RESULTS: During follow-up, ANP decreased significantly within 2 months after HTx and continued of this level, whereas BNP decreased continuously without reaching normal values. The mean ratio of ANP:BNP increased from 3.23 to 8.01 during follow-up. Whereas right atrial pressure (RAP), right ventricular pressure (RVP), right ventricular end-diastolic pressure (RVEDP) and pulmonary capillary wedge pressure (PCWP) did not change during follow-up, cardiac output (CO) improved slightly, but significantly from 5.21 liters/min to 5.9 liters/min (p = 0.035). CONCLUSIONS: Normalization of left ventricular function after orthotopic HTx does not induce an early diminution of ANP and BNP plasma levels to normal concentrations. Although elevated ANP concentrations showed only minimal changes within 1 year, BNP decreased significantly as early as 2 months after HTx, without reaching normal values during the year of follow-up. Also, the ratio of ANP and BNP increased significantly from 3.23 to 8.01. These results demonstrate the contribution of other factors beyond cardiac function that determine the levels of these peptides.     

Improved neurohormonal markers of ventricular function after restoring sinus rhythm by the Maze procedure

BACKGROUND: Clinical results of the Maze procedure for treatment of atrial fibrillation (AF) are excellent, suggesting improved ventricular function after restoring sinus rhythm. However, long-term corresponding effects on the release of cardiac natriuretic peptides and other vasoactive hormones are incompletely investigated after isolated Maze surgery. METHODS: Plasma levels of brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP), antidiuretic hormone, aldosterone, and angiotensin II were measured in 15 patients (mean age, 52 +/- 11 years) undergoing isolated surgical Maze (III) procedures for medically refractory AF, preoperatively and 6 months postoperatively. At the time of blood sampling, hemodynamic correlates were obtained at baseline and after 6 and 12 minutes of rapid ventricular pacing at 150 stimulations/minute. RESULTS: All patients were free of AF at 6-month follow-up. The measured plasma levels of BNP, ANP, and angiotensin II were all significantly lower (p = 0.03) late after the isolated Maze procedure. Cardiac output was significantly higher postoperatively (p < 0.01). Other hemodynamic values and left atrial size were unchanged after surgery. Ventricular pacing caused almost identical hemodynamic changes in atrial pressures before and late after surgery, but the associated plasma ANP response was significantly attenuated postoperatively (p < 0.001). CONCLUSIONS: Levels of cardiac natriuretic peptides and angiotensin II as markers of ventricular function are improved in the long term after clinically successful isolated Maze procedures. ANP response to hemodynamic challenge by ventricular pacing was attenuated postoperatively, possibly due to atrial scarring.     

Perioperative plasma concentrations of atrial and brain natriuretic peptides in patients undergoing hip arthroplasty

Acute hypotension, transient hypoxaemia and elevation of pulmonary artery pressure are well known to occur during cemented arthroplasty. The aim of this prospective clinical study was to characterize the relationship between plasma concentrations of atrial and brain natriuretic peptides (ANP, BNP), and changes in blood pressure in patients undergoing hip arthroplasty. Elevated ANP and BNP levels may be markers of inadequate myocardial reserve. We measured plasma ANP and BNP levels before the operation and 20 minutes after the cementing in 18 patients (54-90 yr). We defined a hypotensive response after cementing as a decrease in systolic blood pressure of more than 15 mm Hg below the pre-cementing value. In the hypotensive group, preoperative values of ANP were 123 +/- 48.5 pg/ml and BNP, 138 +/- 71.7 pg/ml. These values are significantly greater than those in the normotensive group (ANP 35.9 +/- 7.7, and BNP 17.2 +/- 3.2 pg/ml). High preoperative values of ANP and BNP are associated with more hypotension during cemented arthroplasty and could provide an indication of which patients are at risk of this complication.     

Evaluation of atrial and brain natriuretic polypeptides in association with angiotensin-converting enzyme gene polymorphism in Japanese non-diabetic hemodialysis patients

OBJECTIVE: Insertion (I)/deletion (D) polymorphisms in the angiotensin-converting enzyme (ACE) gene have the potential to serve as a marker for an increased risk of cardiovascular events. Increased plasma levels of human atrial natriuretic polypeptide (ANP) and brain natriuretic polypeptide (BNP) are important indexes of cardiac function. The aim of this study was to examine possible relationships between I/D polymorphisms and the myocardial release of ANP and BNP in Japanese hemodialysis (HD) patients (n=131). MATERIAL AND METHODS: We studied 131 non-diabetic hemodialysis patients. The genotype of ACE gene was determined by polymerase chain reaction with a set of specific timers. ANP and BNP levels were measured before HD. RESULTS: The plasma levels of ANP and BNP were significantly lower in the DD genotype group compared to those in the II group. Corresponding levels in the ID genotype group were intermediate between those in the DD and II groups. ACE polymorphism was associated with neither ejection fraction nor left ventricular mass/height index (LVMI), as evidenced by echocardiographic findings (n=107). Plasma levels of ANP were significantly correlated with left atrial diameter (LAD) in patients as a whole, but this correlation was only observed in the II genotype group, and not in the DD or ID groups. Plasma levels of BNP were significantly correlated with LAD, left ventricular end systolic diameter and LVMI in patients as a whole, but these correlations were seen only in the II genotype group. CONCLUSION: The results suggest that the plasma levels of these natriuretic peptides should be evaluated on the basis of ACE polymorphism for assessing cardiac diseases due to volume overload in Japanese HD patients.