Physiologic concentrations of beta-lipotropin stimulate lipolysis in rabbit adipocytes

The proopiocorticomelanotropin (POMC) sequence beta-lipotropin stimulates glycerol release from incubated rabbit adipocytes at a minimal concentration of 10(-9) mol/L. However, when lipolysis inhibiting substances (eg, fatty acids and adenosine) and contaminating peptide degrading activity are continuously removed by fat cell perifusion, the sensitivity is increased to 10(-13) and partly to 10(-14) mol/L beta-lipotropin. This higher sensitivity of the perifused adipocyte could also be demonstrated with alpha-MSH (from 5 X 10(-10) to 10(-13) mol/L). The restimulation of glycerol release was shown for both peptides. We conclude that POMC peptides might be involved in the regulation of lipolysis since the minimal effective concentrations are near to plasma concentrations.     

Myocardial oxygen consumption in chronic heart disease: role of wall stress, hypertrophy and coronary reserve.

The relations between left ventricular mass, mass to volume ratio, systolic wall stress and myocardial oxygen consumption were analyzed in 187 patients with chronic heart disease. The degree of left ventricular hypertrophy is determined by mass, the mass to volume ratio, and pressure and, hence, systolic wall stress. For each condition an inverse relation exists between mass to volume ratio and peak systolic wall stress. In chronic heart disease at least two types of inappropriate left ventricular hypertrophy may occur: (1) low stress hypertrophy with an increased mass to volume ratio, normal left ventricular function and normal or reduced oxygen consumption (MVO₂), whereas (2) high stress hypertrophy has a normal or low mass to volume ratio, impaired left ventricular function and an increased MVO₂. The range of systolic wall stress was 100 to 450 × 10³, dynes/cm² and reflects the stress that could be altered by inotropic interventions and changes in systolic pressure. A similar reserve capacity is present for both the metabolic and the coronary reserves. Total left ventricular oxygen consumption is related to total left ventricular mass. This relation is influenced by the degree of viability of left ventricular mass, by the mass to volume ratio and by inotropic interventions. Left ventricular oxygen consumption per viable mass unit (MVO₂) is significantly correlated with the systolic force per unit cross-sectional area of the left ventricular wall, that is, to left ventricular systolic wall stress.It is concluded that peak systolic wall stress represents one of the major determinants of myocardial oxygen consumption and of ventricular performance. It closely relates to the appropriateness of left ventricular hypertrophy, which may be defined by the relation between systolic pressure, mass to volume ratio and peak systolic wall stress.     

Ventricular function and coronary hemodynamics after intravenous nitroglycerin in coronary artery disease.

Left ventricular dynamics as well as systemic and coronary hemodynamics were determined in 14 patients with coronary artery disease (1) under control conditions, (2) under intravenous infusion of nitroglycerin, (3) under continued infusion of nitroglycerin with restored arterial and pulmonary artery pressures induced by the parallel infusion of dextran. Heart rate was kept constant by atrial pacing.Intravenous nitroglycerin infusion resulted in a significant reduction in left ventricular systolic (20 per cent) and end-diastolic pressure (43 per cent), peak $\text{dp}\text{dt}$ (13 per cent), cardiac index (16 per cent), stroke volume index (15 per cent), and stroke work index (30 per cent). Peak (dp/dt/total pressure) increased (15 per cent). Pulmonary vascular resistance markedly decreased (29 per cent), whereas total peripheral resistance did not change significantly (?3 per cent). Both coronary blood flow of the left ventricle (13 per cent) and myocardial oxygen consumption (15 per cent) decreased parallel to the reduction in preload and afterload. The action of nitroglycerin at restored left ventricular and pulmonary artery pressures was characterized by increase in peak $\text{dp}\text{dt}$ (12 per cent), peak ($\text{dp}\text{dt}$ total pressure) (18 per cent), cardiac index (13 per cent), stroke volume index (14 per cent), and stroke work index (10 per cent). Both coronary blood flow (28 per cent) and myocardial oxygen consumption (21 per cent) increased parallel to the enhancement of ventricular performance.The results demonstrate that intravenous nitroglycerin produces effective diastolic and systolic unloading of the heart associated with reduction in myocardial oxygen consumption and in coronary blood flow. There was marked vascular pooling which quantitatively averaged 437 ± 128 ml. This occurred concomitant with a 43 per cent decrease in left ventricular end-diastolic pressure or a 20 per cent decrease in peak systolic pressure. Significant coronary dilating properties of nitroglycerin could not be detected in these coronary patients. The increase in left ventricular contractility indices at restored pressure suggests a moderate but significant positive inotropic effect of nitroglycerin.     

心率和心率变异性与心力衰竭及预后的相关性

目的　探讨心率及心率变异性与心力衰竭及预后的相关性。方法　入选2010年10月至2012年6月期间就诊宁夏医科大学总医院心内科的慢性充血性心力衰竭患者245例,根据住院期间平均静息心率水平分为3组：A组：50～70次/分;B组：71～90次/分;C组：＞90次/分;共随访1年,完成随访共230例。其中共有97例行动态心电图检查,按患者心功能分级分为Ⅱ级组、Ⅲ级组、Ⅳ级组,同时选择26例正常健康人为对照组。收集上述研究对象的心率变异性时域指标进行对比分析,包括正常RR间期标准差（SDNN）、5　min均值标准差（SDANN）、相邻RR间期相差＞50　ms的个数占总心跳数的百分比（PNN50）、全程相邻RR间期之差的平方根（RMSSD）。结果随着心率水平增加,随访终点射血分数明显降低,再住院率及病死率明显增加（P＜0.01）。不同心率水平心力衰竭患者Cox生存分析显示心率越快,生存率越低。心力衰竭组与对照组相比SDNN、SDANN、PNN50、RMSSD降低（P＜0.01或P＜0.05）,随着心力衰竭程度的加重,SDNN、SDANN、PNN50、RMSSD下降越明显（P＜0.01）。结论　心率越快,心力衰竭预后越差;心力衰竭患者存在心率变异性降低,心率变异性越低,心功能越差。     

Influence of polyunsaturated fats and fat restriction on serum lipoproteins in humans

This study was designed to determine the effects of polyunsaturated fats and of reducing intake of total fat on serum lipids, lipoproteins, and apolipoproteins. Twenty-two normolipidemic women living in a nunnery were given a reference diet (fat/carbohydrate $\text{42}\text{46\%}$ of energy, $\text{P}\text{S}$ ratio 0.16), a polyunsaturated diet ($\text{42}\text{46\%}\text{,}\text{P}\text{S}\text{1.0}$), and a low-fat, polyunsaturated diet ($\text{32}\text{56\%}\text{,}\text{P}\text{S}\text{1.0}$) for 6 weeks each. Serum and lipoprotein lipids were determined by standard procedures, apolipoproteins either by laser immunonephelometry or by rocket immunoelectrophoresis. Consumption of the polyunsaturated diet decreased cholesterol and apolipoprotein B levels in VLDL (?33.1% and ?23.8%) and in LDL (?13.5% and ?8.8%) without affecting HDL. Consumption of the low-fat, polyunsaturated diet resulted in a reincrease of VLDL triglycerides, but not of VLDL cholesterol. Concentration of VLDL apolipoprotein B further fell (?41.6%) and that of apolipoprotein E decreased (?25.9%), resulting in an increased VLDL lipid/apolipoprotein mass ratio. This study indicates that responses to therapeutic polyunsaturated diet are lowered levels of VLDL and LDL, but unchanged levels of HDL. Additional restriction of dietary fat intake alters the VLDL composition with a decrement in apolipoprotein E enriched VLDL particles.     

新生儿先天性心脏病慢性心力衰竭与神经内分泌激活的研究

目的 检测新生儿先天性心脏病（先天性心脏病）的神经内分泌因子,探讨新生儿先天性心脏病是否存在神经内分泌激活及其临床意义.方法 选取2008年10月至2013年8月我院收治的100例新生儿先天性心脏病患者,检测其脑利钠肽（BNP）、醛固酮（ALD）和心房利钠肽（ANP）,另选取年龄及性别与之相匹配的体检正常新生儿30名作为对照组.结果 新生儿先天性心脏病患者血循环中的BNP为（35.7±7.4）pmol/L,ANP为（55.6±7.5）pmol/L,ALD为（546.1 ±42.3）pmol/L,与对照组比较明显增高（P均＜0.01）.三个亚组患儿随着疾病严重程度的加重,神经内分泌的激活就越明显.结论 新生儿先天性心脏病患者的神经内分泌明显激活且具有慢性心力衰竭的特征,并与疾病的严重性密切相关.     

心脏康复对慢性心衰患者心率变异性的影响

目的：观察在标准抗心衰药物治疗的基础上联合心脏康复对慢性力衰竭（CHF）患者心率变异性的影响.方法：本院68例心力衰竭住院患者随机分为对照组34例和治疗组34例,对照组采用标准的抗心衰治疗方案;治疗组采用标准抗心衰治疗＋心脏康复;两组均规范用药6个月.所有患者治疗前后进行24h动态心电图检查心率变异性（HRV）.结果：治疗后,治疗组R-R间期的标准差（SDNN）、每5min窦性R-R平均值的标准差（SDANN）、R-R间期差值的均方根（rMSSD）、相邻两正常窦性R-R间期差值＞50ms的个数所占的百分率（PNN50）较对照组显著增加（P＜0.05）.结论：在标准抗心衰药物治疗的基础上联合心脏康复治疗,可降低交感神经过度激活,增加迷走神经的功能,显著改善HRV,从而改善患者的预后.     

VVI单腔起搏器置入右心室流出道起搏的疗效观察及比较研究

目的观察并比较VVI单腔起搏器置入右心室流出道和右心室心尖部对心动过缓患者6个月后心脏电机械同步性的影响。方法入选20例房颤伴房室传导阻滞及心动过缓需置入VVI单腔起搏器的患者，将右心室流出道起搏的患者10例作为治疗组，同时行右心室心尖部起搏的另外10例作为对照组。观察并比较置人起搏器前后两组的起搏参数、QRS宽度、心功能和生活质量评分情况。结果随访6个月时，两组在起搏阈值、感知阈值、电极阻抗方面差异无统计学意义[（0.48±0．1）mV和（0．56±0．12）mV；（14．7±1．2）V和（12．6±2．3）V；（904±56）Ω和（（815±45）Ω，P〉0．05]，而右心室流出道起搏组的QRS宽度明显缩短[（108．3±11．2）ms和（134．5±12．6）ms，P〈0．05]，且心功能和生活质量评分明显改善[（58．9±2．5）％和（54．3±2．5）％，61．8±2．3和56．2±5．1，P〈0．05]。结论VVI单腔起搏器置入右心室流出道起搏较心尖部起搏更接近生理情况，能增加患者的心脏电机械同步性，提高心功能及改善预后。     

Three-stage Palliation of Hypoplastic Left Heart Syndrome in the University HealthSystem Consortium

Objective. The objective of this study was to describe current management and short-term outcomes for patients with hypoplastic left heart syndrome representative of nationwide experience. Additionally, this study identifies risk factors associated with mortality in patients undergoing staged surgical palliation. Design. The University HealthSystem Consortium database was queried to identify all hospital admissions between 1998 and 2007 with a diagnosis of hypoplastic left heart syndrome. Procedure codes were used to determine surgical management, and outcomes were ascertained by discharge status (discharged, transferred, or expired). Results. Discharge data were present from 118 hospitals in the United States. First-stage surgical palliation was performed in 1949 neonates with 30% mortality. Mortality decreased from 43% in 1998 to 18% in 2007. Large institutional case volume and later era of surgery were associated with improved operative mortality in first-stage palliation. Primary cardiac transplantation was performed in 28 neonates, and rescue transplantation in 11, with 36% mortality. Second-stage palliation was performed in 1244 patients with 5.2% mortality, and third-stage palliation was performed in 1084 patients with 4.1% mortality. An additional 62 patients over 1 month of age at time of admission received cardiac transplantation with 15% mortality. Conclusions. First-stage palliative mortality for hypoplastic left heart syndrome fell dramatically over the past decade, while that for second- and third-stage procedures remained stable. The cumulative operative mortality for three-staged repair of hypoplastic left heart syndrome was 39% over the decade, but fell to 24% for procedures in 2007.     

心力衰竭管理模式探讨

目的:评价不同管理模式对慢性收缩性心力衰竭(心衰)患者神经内分泌、心功能、心脏事件、生活质量和医疗费用的影响。方法:120例慢性心功能不全患者,在常规治疗心衰的前提下,随机分为心衰管理组和心衰非管理组各60例,治疗后两年其对神经内分泌、心功能、心脏事件、生活质量和医疗费用的影响。结果:心衰管理组治疗后心功能、生活质量、神经内分泌较心衰非管理组治疗后改善(P<0.05),心衰恶化再入院减少(P<0.05),心脏事件较心衰非管理组明显减少(P<0.05),年心衰治疗费用较后者减少(P<0.05),差异均有统计学意义。结论:通过心衰管理能改善心功能及生活质量,减少心衰医疗费用、心脏事件的发生。     

右腋下剖胸小儿心内直视术

目的 :探讨右侧剖胸小切口的手术要点及手术指征。　　方法 :本组 10 2例患者经右腋下小切口剖胸及体外循环下行小儿心内直视术 ,其中房间隔缺损 2 4例 ,室间隔缺损 6 8例 ,法乐四联症 5例 ,室间隔缺损合并房间隔缺损 3例 ,右心室双出口、Ebstein畸形各 1例。合并畸形 :左上腔静脉 4例 ,右心室双腔及动脉导管未闭各 1例。　　结果 :全组患者无死亡。　　结论 :切口的正确选择是术野良好显露的前提 ,主动脉插管是手术成功的关键。该切口适用于大部分常见先天性心脏病的矫治。     

Uma década de transplantação cardíaca em Coimbra. O valor da experiência

Introduction and ObjectivesTo analyze the experience gained in 10 years of the heart transplantation program of the University Hospital of Coimbra.MethodsBetween November 2003 and December 2013, 258 patients with a mean age of 53.0±12.7 years (3‐72 years) and predominantly male (78%) were transplanted. Over a third of patients had ischemic (37.2%) and 36.4% idiopathic cardiomyopathy. The mean age of donors was 34.4±1.3 years and 195 were male (76%), with gender difference between donor and recipient in 32% of cases and ABO disparity (non‐identical groups but compatible) in 18%. Harvest was distant in 59% of cases. In all cases total heart transplantation with bicaval anastomoses, modified at this center, was used. Mean ischemia time was 89.7±35.4 minutes. All patients received induction therapy.ResultsEarly mortality was 4.7% (12 patients) from graft failure and stroke in five patients each, and hyperacute rejection in two. Thirteen patients (5%) required prolonged ventilation, 25 (11.8%) required inotropic support for more than 48 hours, and seven required pacemaker implantation. Mean hospital stay was 15.8±15.3 days (median 12 days). Ninety percent of patients were maintained on triple immunosuppressive therapy including cyclosporine, the remainder receiving tacrolimus. In 23 patients it was necessary to change the immunosuppression protocol due to renal and/or neoplastic complications and humoral rejection. All but two patients have been followed in the Surgical Center. Fifty patients (19.4%) subsequently died from infection (18), cancer (10), vascular (eight), neuropsychiatric (four), cardiac (two) or other causes (eight). Forty‐six patients (17.8%) had episodes of cellular rejection (>2 R on the ISHLT classification), eight had humoral rejection (3.1%), and 22 have evidence of graft vascular disease (8.5%). Actuarial survival at 1, 5, and 8 years was 87±2%, 78±3% and 69±4%, respectively.ConclusionThis 10‐year series yielded results equivalent or superior to those of centers with wider and longer experience, and have progressively improved following the introduction of changes prompted by experience. This program has made it possible to raise and maintain the rate of heart transplantation to values above the European average.     

风湿性心脏瓣膜置换术1 061例临床分析

目的:对1061例风湿性心脏病瓣膜置换术进行早期疗效观察及临床分析。方法:对2000年1月～2005年12月入院施行瓣膜置换术的风湿性心脏瓣膜病例进行回顾总结。结果:1061例中,术后早期病死率1.32%(14例),主要死亡原因为低心排血量综合征(3例)和心室颤动(3例)。术后早期并发症发生率6.41%(68例),其中低心排血量综合征13例、严重心律失常12例,两者占36.76%。结论:术前改善心功能、术中加强心肌保护和改进手术方法、积极处理术后并发症是提高风湿性心脏病瓣膜置换术疗效的重要措施。