Abnormalities of the peripheral circulation and respiratory function in patients with severe heart failure.

To investigate the peripheral circulatory and respiratory abnormalities which occur in patients with heart failure, forearm and calf blood flow were measured before and after upright exercise, and respiratory gas exchange was measured during exercise in 26 patients with severe heart failure. Compared with a group of normal subjects the patients had reduced limb blood flow at rest and the response of limb blood flow to upright exercise was also abnormal. The increase in calf blood flow after exercise and the reduction in blood flow in the non-exercising forearm were both smaller in patients than in controls. There was a significant correlation between the maximum exercise duration of the patients and calf blood flow both after exercise and at rest. Compared with another group of control subjects the patients had a higher minute ventilation during exercise and a reduced oxygen consumption. The respiratory exchange ratio during exercise was also higher in patients than in controls. This suggests that there is early onset of anaerobic metabolism during exercise in patients with severe heart failure.     

Abnormalities of the peripheral circulation and tolerance to exertion of patients with heart failure

Chronic heart failure is attended by a number of abnormalities of peripheral circulation. To a great extent, these abnormalities determine the patients' functional symptoms, their tolerance to exercise and their response to treatment, at least in the short term. The response to exercise of heart failure patients depends on their maximal oxygen consumption which is determined by their maximal cardiac output and by various peripheral adjustments, such as distribution of regional blood flow and peripheral oxygen extraction. Abnormalities of peripheral arteriolar and capillary dilatation are determined by hyperstimulation of neurohormonal systems. An increase in maximal muscular blood flow, which determines the patients' capacity of exercise, can be obtained with drugs which increase the muscular perfusion pressure (inotropic drugs) or which decrease muscular resistances without lowering the perfusion pressure (venous or balanced vasodilators, diuretics). Physical rehabilitation may improve maximal oxygen consumption by improving the peripheral use of oxygen. Thus, a better understanding of the physiopathology of heart failure will in the future improve the functional symptoms of these patients and prolong their survival, which has not always been the case with conventional therapies.     

心衰并呼衰患者外周血细胞免疫功能状态的研究

目的探讨不同心功能和心力衰竭并呼吸衰竭患者外周血T、Th、Ts、Th/Ts、TNF-α和TGF-β的表达变化及其临床意义。方法采用流式细胞术和酶联免疫吸附法分析65例Ⅱ级、Ⅲ级、心力衰竭合并呼吸衰竭病人及40例健康人外周血的表达和变化情况。结果健康人、心功能Ⅱ级Ⅲ级心力衰竭合并呼吸衰竭等组之间外周血总T细胞未见明显变化;Ts与心力衰竭程度呈正相关（P〈0.05）;Th与心力衰竭程度呈负相关（P〈0.05）。Th/Ts降低与心力衰竭程度呈负相关（P〈0.05）。并且心力衰竭合并呼吸衰竭时这种趋势表现得更加明显。心功能Ⅲ和心力衰竭合并呼吸衰竭血浆中TNF-α和TGF-β的含量高于对照组（P〈0.05）;心力衰竭合并呼吸衰竭病人血浆中TNF-α和TGF-β高于心功能Ⅱ（P〈0.05）。结论炎症反应是加重心力衰竭的重要因素,检测心力衰竭合并呼吸衰竭患者外周血中T细胞亚群和炎症因子的变化情况有助于指导治疗和预测预后。     

Relationship between endothelin-1 extraction in the peripheral circulation and systemic vascular resistance in patients with severe congestive heart failure

OBJECTIVESThis study was done to determine the spillover and extraction of endothelin-1 (ET-1) in the peripheral circulation, and to evaluate the factors that regulate local ET-1 extraction in the peripheral circulation in patients with congestive heart failure (CHF).BACKGROUNDThe relationship between the spillover and extraction of the ET-1 in the peripheral circulation and systemic vascular resistance (SVR) has not been fully clarified.METHODSWe measured plasma levels of ET-1 both in femoral artery (FA) and femoral vein (FV) in 93 patients with CHF.RESULTSPlasma ET-1 was significantly higher in FV than in FA in New York Heart Association (NYHA) functional class II patients, but there was no difference of ET-1 between FA and FV in functional class III patients. In patients with functional class IV, plasma ET-1 was significantly lower in FV than in FA, and SVR was significantly higher than in patients with NYHA class II or class III. Moreover, a significant positive correlation existed between plasma ET-1 extraction across the lower leg and SVR in these patients. Among the various neurohumoral factors and hemodynamics, plasma levels of ET-1, angiotensin II in the FA showed an independent and significant relationship with the plasma arteriovenous difference of ET-1 in the lower limb.CONCLUSIONSCirculating ET-1 is extracted in peripheral circulation in patients with severe CHF, suggesting the possibility of upregulation of ET receptors of vascular beds in the lower limb in these patients. The peripheral extraction of ET-1 correlates with SVR in severe CHF patients and is mainly regulated by the local ET-1 and renin angiotensin systems.     

Abnormalities of skeletal muscle in patients with chronic heart failure

We have examined muscle strength, mitochondrial enzyme activity, histochemistry and fibre size in the quadriceps muscle of 9 patients with severe chronic heart failure. A needle biopsy of the quadriceps muscle was taken with patients at rest. Maximum oxygen uptake was measured during treadmill exercise. Mean maximal oxygen consumption was 11.7 ml.kg-1.min-1. Isometric maximum voluntary contraction was reduced to 55% of the predicted value for weight. Eight biopsies were abnormal. Findings included increased acid phosphatase, increased interstitial cellularity, excess intracellular lipid accumulation, atrophy of both type I and II fibres and variation in size with hypertrophy and atrophy of fibers. Muscle fibre capillary density and the activity of mitochondrial enzymes were normal. Changes in skeletal muscle strength may play a role in the limitation of exercise capacity seen in patients with congestive heart failure.     

Abnormalities of endothelial function in patients with predialysis renal failure

BACKGROUND: Endothelial dysfunction plays an important role in the development of atherosclerotic vascular disease, which is the leading cause of mortality in patients with chronic renal failure. OBJECTIVE: To examine the relation between predialysis renal failure and endothelial function. DESIGN: Two groups were studied: 80 patients with non-diabetic chronic renal failure and 26 healthy controls, with similar age and sex distributions. Two indices of endothelial function were assessed: high resolution ultrasonography to measure flow mediated endothelium dependent dilatation of the brachial artery following reactive hyperaemia, and plasma concentration of von Willebrand factor. Endothelium independent dilatation was also assessed following sublingual glyceryl trinitrate. The patients were divided into those with and without overt atherosclerotic vascular disease. RESULTS: Although patients with chronic renal failure had significantly impaired endothelium dependent dilatation compared with controls (median (interquartile range), 2.6% (0.7% to 4.8%) v 6.5% (4.8% to 8.3%); p < 0.001) and increased von Willebrand factor (254 (207 to 294) v 106 (87 to 138) iu/dl; p < 0.001), there was no difference between renal failure patients with and without atherosclerotic vascular disease. Within the chronic renal failure group, endothelium dependent dilatation and von Willebrand factor were similar in patients in the upper and lower quartiles of glomerular filtration rate (2.7% (0.7% to 6.7%) v 2.8% (1.1% to 5.0%); and 255 (205 to 291) v 254 (209 to 292) iu/dl, respectively). Endothelium independent dilatation did not differ between the renal failure or control groups and was also similar in patients with renal failure irrespective of the degree of renal failure or the presence of atherosclerotic vascular disease. CONCLUSIONS: Endothelial function is abnormal in chronic renal failure, even in patients with mild renal insufficiency and those without atherosclerotic vascular disease, suggesting that uraemia may directly promote the development of atherosclerosis early in the progression of chronic renal failure.     

Abnormalities of the respiratory function and control of ventilation in patients with anorexia nervosa

BACKGROUND: Anorexia nervosa is a good model to study the effects of malnutrition on the respiratory system, since it excludes the consequences that some chronic diseases can have on the lung. OBJECTIVE: The objective of this study was to assess pulmonary function and alterations in the respiratory system in patients with anorexia nervosa. METHODS: Twenty-two women, 12 with anorexia nervosa and 10 healthy volunteers, were studied. Anthropometric data were gathered for all the participants. In every case, an arterial blood gas test and functional respiratory study, that included spirometry, plethysmography, measure of maximum muscular respiratory pressure and study of the ventilatory pattern at baseline and after hypercapnic stimulation, were performed. RESULTS: No significant differences were found in mean age and height in both groups of patients but there was a difference in body mass index (p < 0.05). In pulmonary function tests, an increase in residual volume (RV), RV/total lung capacity (TLC) ratio and functional residual capacity and a decrease in maximum respiratory pressure were found in patients with anorexia nervosa compared to the control group (p < 0.05). Differences were also found in the ventilatory pattern, with a reduction in minute ventilation and occlusion pressure as well as a decreased response of these parameters to hypercapnic stimulation (p < 0.05) in the patients with anorexia nervosa. CONCLUSION: In patients with anorexia nervosa, a significant elevation in RV, in the RV/TLC ratio and in functional residual capacity and a decrease in the maximum respiratory pressure were noted. In addition, they present an alteration in the central respiratory drive and a response of the respiratory system to hypercapnic stimulation. Although these alterations have no repercussion on the maintenance of gas exchange in baseline conditions, they may have in extreme situations.     

2019新型冠状病毒对慢性心力衰竭患者的影响

目前2019新型冠状病毒（SARS-CoV-2）疫情为我国的公共卫生事业带来极大挑战。在已报道的新型冠状病毒肺炎病例中以老年患者居多,且有较大一部分并发慢性基础疾病,其中包括心血管疾病。心力衰竭（HF）是各种心血管疾病的终末期,患有该疾病的患者更应该在此次疫情中加强认知与管理。因此,以下将对SARS-CoV-2在HF疾病方面的影响做一综合论述。     

慢性重度充血性心力衰竭患者血清甲状腺激素和心功能变化的关系

目的观察探讨慢性充血性心力衰竭（CHF）患者甲状腺激素异常变化的临床意义。方法各种病因的CHF患者71例，其中重度CHF23例以及健康对照组25例进行血清甲状腺激素水平的测定。结果发现CHF组中三碘甲状腺原氨酸，激离三碘甲状腺原氨酸。反三碘甲状腺原氨酸与对照组比较有显著差异（P＜0．05），而促甲状腺激素无明显改变。心力衰竭程度越重，激素水平变化越明显。经治疗后激素水平有上升，较前好转。结论血清甲状腺激素变化作为判断CHF严重程度，治疗和预后具有一定临床意义。     

Diastolic function in patients with severe heart failure: comparison of the effects of enoximone and nitroprusside

To assess whether the phosphodiesterase inhibitor enoximone has a specific, direct effect on left ventricular diastolic function distinct from its inotropic and vasodilator actions, we compared the effects of enoximone and the pure vasodilator nitroprusside in 11 patients with severe heart failure. Mean (+/- SEM) left ventricular ejection fraction was 0.20 +/- 0.03. Simultaneous left ventricular pressure and radionuclide angiographic volume were obtained at baseline, during infusion of nitroprusside, and after intravenous administration of enoximone. Left ventricular end-diastolic pressure (LVEDP) and volume (LVEDV) decreased with both agents (p less than .01 vs control); LVEDP was lower for nitroprusside than for enoximone (p less than .01) despite a similar LVEDV. Nitroprusside decreased the time constant of exponential left ventricular pressure decay, TL (measured by the logarithmic method), from 84 +/- 10 to 65 +/- 8 msec (p less than .01) but had no significant effect on TD (measured by the derivative method), maximum negative dP/dt, or the peak rate of early diastolic filling. Enoximone shortened TL from 86 +/- 12 to 61 +/- 9 msec (p less than .01) and increased maximum negative dP/dt from 897 +/- 101 to 1135 +/- 134 mm Hg/sec (p less than .01) but did not affect TD or the peak filling rate. The left ventricular diastolic pressure-volume relation was shifted downward in only three of 11 patients on nitroprusside and three of 11 patients on enoximone, and these shifts were attenuated by adjusting for simultaneous changes in right atrial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of left ventricular systolic and diastolic function in patients with idiopathic dilated cardiomyopathy and mild heart failure versus those with severe heart failure

Achieving recommended cholesterol and triglyceride targets for the prevention of cardiovascular events is difficult and frequently requires the use of >1 lipid-lowering medication. This study evaluated the tolerability and effectiveness of combination regimens in high-risk dyslipidemic patients resistant to monotherapy. A retrospective chart review of all patients referred to a cardiovascular risk reduction clinic over a 7.5-year period identified 136 patients who received combination therapy with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) plus fibrate (n = 106) or a statin plus niacin (n = 30) regimen. During follow-up (mean 18.5 months), 28 patients (20.6%) discontinued combination therapy: 11 (8.1%) experienced myalgia with or without elevated creatine kinase, 3 had gastrointestinal upset, and 1 had asymptomatic creatine kinase elevation. No patient had combination therapy discontinued due to elevated liver enzymes. Medications were stopped in 8 patients for reasons other than reported adverse effects or biochemical abnormalities, and 5 patients were switched to alternate monotherapy. Mean percent change from baseline to treatment with combination therapy for total cholesterol (-35%), low-density lipoprotein cholesterol (-37%), high-density lipoprotein cholesterol (+23%), triglycerides (-62%), and total cholesterol/high-density lipoprotein cholesterol ratio (-41%) were all statistically significant (p <0.01). These results demonstrate that combination statin-fibrate and statin-niacin regimens are safe and effective in managing dyslipidemias in most patients at risk for cardiovascular events who are inadequately treated with one of these agents alone.     

SARS患者甲状腺功能检测分析

测定 8例严重急性呼吸综合征 (SARS)患者血浆甲状腺激素水平。结果显示这些患者的血浆TT3 、FT3 下降 ,rT3 升高 ,符合低T3 综合征诊断。     

有创后序贯无创机械通气治疗重度COPD呼吸衰竭患者疗效观察

目的探讨有刨与无创序贯机械通气在治疗COPD重症呼吸衰竭的效果。方法选择40例COPD呼吸衰竭患者，随机分为两组，20例为有刨与无创序贯治疗组，20例为对照组，常规有创通气，以PSV方式至撤机。观察有创通气时间、总机械通气时间，医院获得性肺炎，住院时间、治疗费用等的差异；结果序贯治疗组与对照组，有创通气时间分别是（8．03±1．68）d和（15．02±2．96）d，总机械通气时间分别是（11．38±3．25）d和（19．29±4．11）d，VAP发生例数分别是3例和17例，住院时间分别是（15．89±2．01）d和（26．21±1．57）d，治疗费用分别是（1．09±0．01）万元和（1．92±0．06）万元，两组间比较差异有显著差异性（P〈0．05）。结论对COPD重症呼吸衰竭病例，采用有创与无刨序贯机械通气治疗可降低有刨机械通气时间、减少VAP的发生，减少住院时间及住院费用。     

Dobutamine potentiates the peripheral chemoreflex in patients with congestive heart failure

BACKGROUND: beta-Adrenergic agonists may increase chemoreflex sensitivity to hypoxia in normal humans. Chemoreflex function is important in the pathophysiology of heart failure. Whether the beta-1 agonist dobutamine, which is frequently administered to patients with heart failure, alters their chemoreflex sensitivity is not known. METHODS: We tested the hypothesis that dobutamine increases chemoreflex sensitivity in patients with congestive heart failure (CHF) using a randomized, double-blinded, placebo-controlled study design. We assessed the influence of dobutamine on minute ventilation and hemodynamics during normoxic breathing and during peripheral chemoreflex deactivation by hyperoxia (100% O(2)) in 9 patients with CHF. RESULTS: Dobutamine increased minute ventilation in patients with CHF (9.4+/-0.9 versus 8.4+/-0.7 L/min, P=.005) during normoxia. Peripheral chemoreflex deactivation by hyperoxia suppressed the ventilatory effects of dobutamine (10.4+/-1.4 L/min for dobutamine versus 10.0+/-1.2 L/min for placebo, P=.34). CONCLUSIONS: Dobutamine increases ventilation during normoxia, but not during hyperoxia in patients with CHF. We conclude that dobutamine enhances peripheral chemoreflex sensitivity in patients with congestive heart failure.     

心肺功能不全患者血乳酸浓度变化的研究

目的探讨呼吸衰竭、呼吸衰竭合并急性左心功能衰竭患者血乳酸（LAC）浓度的变化,及与血氧分压（PaO2）之间的相互关系。方法用GEMpremier血气、电解质、血乳酸仪测定正常对照组、呼吸衰竭患者、呼吸衰竭合并急性左心功能衰竭患者的血LAC浓度和血气分析。结果三组患者血LAC浓度有显著性差异（P〈0.01）,PaO2与血LAC呈明显的负相关（P〈0.01）。结论血LAC的测定有助于了解组织细胞缺氧情况,呼吸衰竭患者同时监测血气和血LAC,可帮助判断患者是否合并急性左心功能衰竭。     

Effect of angiotensin-converting enzyme inhibitors on the peripheral circulation in heart failure.

In patients with chronic heart failure, the increase in blood flow to working muscle is attenuated and oxygen consumption is lower for any given workload of exercise, compared with normal subjects. This impaired metabolic vasodilation during exercise cannot be restored with short-term administration of angiotensin-converting enzyme (ACE) inhibitors. However, long-term ACE inhibition increases blood flow to skeletal muscle, and this increase is closely correlated with improvement in systemic oxygen consumption. The delayed effect of ACE inhibitors may be related to an interference with the vascular tissue renin-angiotensin system and remodeling of the vascular wall. In addition, endothelial-dependent dilation in response to acetylcholine is blunted in the forearm of patients with chronic heart failure, indicating an impaired endothelial function in this setting. There is experimental evidence that long-term ACE inhibition improves endothelial dysfunction; thus, one might speculate that the beneficial long-term effect of ACE inhibitors on peripheral flow may be, in part, related to its ability to restore normal endothelial function. Vasodilators such as hydralazine that improve blood flow to working muscle after acute administration do not increase skeletal muscle oxygen consumption, indicating that oxygen utilization is not improved. Ultrastructural analysis of skeletal muscle revealed that intrinsic alterations of skeletal muscle exist in patients with chronic heart failure; that is, the oxidative capacity of skeletal muscle is impaired in severe heart failure and contributes to the reduced exercise capacity.(ABSTRACT TRUNCATED AT 250 WORDS)