Accuracy of oximetry with thermistor (OxiFlow) for diagnosis of obstructive sleep apnea and hypopnea

OBJECTIVES: To evaluate the diagnostic accuracy for obstructive sleep apnea and hypopnea (OSAH) of the OxiFlow (OF) device which combines oximetry with recording of thermistor airflow. DESIGN & SETTING: Patients scheduled for overnight diagnostic polysomnography (PSG) were studied with OF either simultaneously during laboratory PSG (L-OF, n=86), at home on a separate night (H-OF, n=66), or both (n=55). PATIENTS: 97 patients with suspected OSAH, of whom 40 had OSAH defined as an apnea-hypopnea index (AHI) of more than 15 events per hour of sleep on PSG. INTERVENTIONS: NA. MEASUREMENTS & RESULTS: The automated respiratory disturbance index (RDI) generated by the OF software considerably underestimated the AHI by PSG for both L-OF and H-OF. Altering the parameters for hypopnea identification by the software did not improve this. Visual inspection of the computerized OF tracings added considerable diagnostic information, but a manual count of RDI during visual review overestimated AHI. For the identification of cases vs. non-cases of OSAH, receiver operating characteristic area-under-the-curve statistics ranged from 0.77-0.90 for L-OF and from 0.71-0.77 for H-OF. Combining automated analysis with subsequent visual inspection of OF tracings yielded an overall sensitivity of 86% and specificity of 74% for the diagnosis of OSAH during H-OF recordings. Analysis of potential technician time saved indicated a benefit from the use of OF. CONCLUSIONS: OF has diagnostic utility for the identification of OSAH. However, because of hardware and software limitations, it is unclear whether this device is superior to oximetry alone.     

Cardiac natriuretic peptides and continuously monitored atrial pressures during chronic rapid pacing in pigs

Changes in atrial natriuretic peptide (ANP), N-terminal proatrial natriuretic peptide and brain natriuretic peptide (BNP) were evaluated in relation to continuously monitored atrial pressures in a pacing model of heart failure. Pigs were subjected to rapid atrial pacing (225 beats min-1) for 3 weeks with adjustments of pacing frequencies if the pigs showed overt signs of cardiac decompensation. Atrial pressures were monitored by a telemetry system with the animals unsedated and freely moving. Left atrial pressure responded stronger and more rapidly to the initiation of pacing and to alterations in the rate of pacing than right atrial pressure. Plasma natriuretic peptide levels were measured by radioimmunoassay and all increased during pacing with BNP exhibiting the largest relative increase (2.9-fold increase relative to sham pigs). Multiple regression analysis with dummy variables was used to evaluate the relative changes in natriuretic peptides and atrial pressures and the strongest correlation was found between BNP and left atrial pressure with R 2=0.81. Termination of pacing resulted in rapid normalization of ANP values in spite of persistent elevations in atrial pressures. This may reflect an increased metabolism or an attenuated secretory response of ANP to atrial stretch with established heart failure. In conclusion, 3 weeks of rapid pacing induced significant increases in atrial pressures and natriuretic peptide levels. All the natriuretic peptides correlated with atrial pressures with BNP appearing as a more sensitive marker of cardiac filling pressures than ANP and N-terminal proatrial natriuretic peptide.     

Regional cardiac expression and concentration of natriuretic peptides in patients with severe chronic heart failure.

The purpose of this study was to examine the regional cardiac mRNA expression and concentration of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) in relation to the circulating peptide concentrations in patients with chronic heart failure (CHF). The myocardial mRNA levels and peptide concentrations of BNP and ANP were analysed in seven different regions of the heart from patients undergoing cardiac transplantation. Autopsy samples from individuals without known cardiovascular disease were used as controls. The plasma levels of natriuretic peptides and their N-terminal propeptides, Nt-proBNP and Nt-proANP, were measured in the CHF patients and healthy volunteers. In the autopsy specimens, the atrial regions appeared to contain the highest peptide levels for BNP as well as ANP, the atrioventricular ratio being 12-262 and 72-637-fold, respectively. In the CHF patients there was a relative shift towards the ventricle for BNP, reducing the atrioventricular ratio to 6-16-fold. The circulating concentrations of BNP/Nt-proBNP in the CHF patients correlated closely to the BNP mRNA expression in most myocardial regions including the left ventricle (r = 0.72, P < 0.001). For circulating concentrations of ANP/Nt-proANP, such correlation were limited to the left atrium free wall (r = .66, P < 0.002). Thus, of the two natriuretic peptides, BNP/Nt-proBNP may be a better reflector of left ventricular overload.     

Regional cardiac expression and concentration of natriuretic peptides in patients with severe chronic heart failure

The purpose of this study was to examine the regional cardiac mRNA expression and concentration of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) in relation to the circulating peptide concentrations in patients with chronic heart failure (CHF). The myocardial mRNA levels and peptide concentrations of BNP and ANP were analysed in seven different regions of the heart from patients undergoing cardiac transplantation. Autopsy samples from individuals without known cardiovascular disease were used as controls. The plasma levels of natriuretic peptides and their N‐terminal propeptides, Nt‐proBNP and Nt‐proANP, were measured in the CHF patients and healthy volunteers. In the autopsy specimens, the atrial regions appeared to contain the highest peptide levels for BNP as well as ANP, the atrioventricular ratio being 12–262 and 72–637‐fold, respectively. In the CHF patients there was a relative shift towards the ventricle for BNP, reducing the atrioventricular ratio to 6–16‐fold. The circulating concentrations of BNP/Nt‐proBNP in the CHF patients correlated closely to the BNP mRNA expression in most myocardial regions including the left ventricle (r=0.72, P < 0.001). For circulating concentrations of ANP/Nt‐proANP, such correlation were limited to the left atrium free wall (r=0.66, P < 0.002). Thus, of the two natriuretic peptides, BNP/Nt‐proBNP may be a better reflector of left ventricular overload.     

Plasma BNP and NT-proBNP assays by automated immunoanalyzers: analytical and clinical study

The plasma concentrations of natriuretic peptides, BNP and NTproBNP, have been shown to be markers for the diagnosis of congestive heart failure (CHF). In this study, plasma BNP and NTproBNP concentrations were evaluated and stratified according to renal function, body mass index (BMI), and New York Heart Association (NYHA) classification. Comparison studies between the 2 natriuretic peptide markers were performed. Assays for BNP were performed with a Triage reagent pack (Biosite, Inc) on an Access 2 immunoanalyzer (Beckman-Coulter); NTproBNP assays were performed with a Roche reagent pack on an Elecsys 20.10 immunoanalyzer (Roche Diagnostics). Plasma samples were collected from consecutive patients hospitalized for cardiac disorders at our institution. Nonparametric tests were used for statistical analyses. The results show that alterations of renal function had less impact on BNP (p = 0.9) than on NTproBNP concentrations (p <0.0001). BNP and NTproBNP levels were lower in obese patients with CHF (515 +/- 61 ng/L and 1652 +/- 124 ng/L, respectively) than in lean patients (900 +/- 85 ng/L and 6686 +/- 749 ng/L). Although NTproBNP levels averaged about 10 times higher than BNP levels, there was significant correlation between these 2 markers (Deming regression r2 = 0.40, IC: 0.95). In conclusion, plasma BNP and NTproBNP assays are both useful for the diagnosis of CHF and left ventricular dysfunction. However, renal function and obesity must be taken into account for clinical interpretation. These assays have good analytical performance and the choice between them depends on local preference.     

Brain natriuretic peptide

Plasma levels of various neurohumoral factors are activated and have an important role of the pathophysiology of congestive heart failure (CHF). Atrial natriuretic peptide (ANP) and brain (or B-type) natriuretic peptide (BNP) are secreted from cardiomyocytes in response to atrial or ventricular wall stretch. The natriuretic peptides have a fundamental role in cardiovascular remodeling, volume homeostasis, and the response to myocardial injury. Clinical investigations of these peptides have focused on their diagnostic usefulness for heart failure and left ventricular dysfunction and their prognostic usefulness after acute coronary syndromes and heart failure. In patients with left ventricular systolic dysfunction, a high plasma BNP level is an independent prognostic predictor of CHF patients, suggesting that the compensatory activity of the cardiac natriuretic peptide system is attenuated as mortality increases in chronic CHF patients with high plasma levels of ANP and BNP. BNP is more useful than ANP for diagnosis and management of CHF. Recently, rapid BNP assay is available in our country, rapid measurement of BNP in the emergency department may improve the evaluation and treatment of patients with acute dyspnea and thereby reduced the time to discharge and the total cost of treatment. In addition, BNP-guided treatment of heart failure may reduce total cardiovascular events, and delayed time to first event combination with intensive clinically guided treatment.     

Non-radioimmunometric NT-ProBNP and BNP assays: impact of diluent, age, gender, BMI

We examined the analytical correlation between non-radioimmunometric plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP) and evaluated whether NT-proBNP or BNP was influenced by age, gender and/or body mass index (BMI). Electro-chemiluminescence (Elecsys, Roche diagnostic) and a single use fluorescence (Triage, Biosite) immunoassays were used to measure NT-proBNP and BNP levels respectively. As a preliminary, seven different diluents usually used in immunoassays were tested and the "speciality diluent" (Ortho Clinical Diagnostic) was validated to increase the linearity of BNP immunoassay above 5000 pg/mL. Data were collected prospectively from patients admitted to the emergency department for acute dyspnea. Plasma BNP and NT-proBNP were measured at admission. Reference diagnosis was adjudicated by 2 independent cardiologists using the European Society of Cardiology guidelines. One hundred and sixty consecutive patients were included: 84 females and 76 males, mean age 80.1 +/- 13.5 (16-98). The analytical correlation between NT-proBNP and BNP was satisfactory using the equation: log10(NT-proBNP) = 1.1xlog10(BNP) + 0.57 and a correlation r = 0.93. This was established over a wide range of concentration (5-6400 pg/mL for BNP). Age and gender were known to influence circulating BNP levels. We showed that the correlation between BNP and NT-proBNP was not influenced by age, gender and body mass index of patients which suggests that the distribution of both peptides was similarly affected by these parameters. We conclude that NT-proBNP, as assayed in the present study, correlates closely with BNP. Used in conjunction with other clinical information, rapid measurement of BNP or NT-proBNP is useful in establishing or excluding the diagnosis of congestive heart failure in patients with acute dyspnea.     

Brain natriuretic peptide: physiological, biological and clinical aspects

Brain natriuretic peptide is one member of the natriuretic peptide family, including also ANP, CNP, DNP and urodilatin. In human, brain natriuretic peptide is mainly secreted by the cardiac ventricles. BNP is synthetized as pre-proBNP form, secondary cleaved in proBNP, itself equimolarly cleaved in BNP and NT-proBNP. The biological action of BNP is mediated by the NPR-A receptor. This peptide is eliminated from the systemic circulation by a neutral endopeptidase and by a clearance receptor (NPR-C). The BNP and NT-proBNP concentrations are measured using automated rapid immunoassay techniques. Plasma concentrations of the two peptides physiologically increase with age and are found to be higher in women than in men. The action of BNP against fluid expansion is explained by its vascular (vasodilatation), renal (diuretic and natriuretic) and cerebral activities. The measurement of these two peptides contributes to the diagnosis of heart failure. These peptides are prognostic markers both in heart failure and in acute coronary syndromes. In renal insufficiency, the interpretation of the increase in these two peptide concentrations may be difficult, particularly with the NT-proBNP which is mainly excreted by the kidneys.     

Relationship between obstructive sleep apnea and diurnal leptin rhythms

STUDY OBJECTIVES: Several studies have reported an association between obstructive sleep apnea and leptin, a hormone that influences satiety and body weight. We evaluated the relationship of leptin levels and the overnight change in levels with sleep apnea. DESIGN: Cross-sectional analysis of data from a prospective cohort study. SETTING: Case Western Reserve University General Clinical Research Center. PATIENTS OR PARTICIPANTS: A total of 138 individuals participating in the Cleveland Family Study--59% women, 45% African-American, with mean apnea-hypopnea index (AHI) of 6.9 (range 0-106)--were studied. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Serum leptin was measured at 10:00 pm to 11:00 pm and at 7:00 am to 8:00 am. Leptin levels in both the morning and evening were positively correlated with apnea-hypopnea index (AHI) in age-, sex-, and race-adjusted analyses (P < .0001) but not after additional adjustment for body mass index. The evening/morning leptin ratio, however, was associated with AHI independent of age, sex, race, body mass index, and waist-hip ratio (P = .03). Conversely, AHI was an independent predictor of the leptin ratio (P = .001) and more predictive than arousal index, oxygenation indices, time asleep, or sleep-stage distribution. An AHI > 15 was associated with a 23% increase in leptin ratio. CONCLUSIONS: These findings suggest that sleep apnea may suppress secretion of leptin in the morning. Alternatively, the relative elevation in evening leptin may influence apnea pathogenesis.     

Membrane-bound guanylate cyclase as the receptor of natriuretic peptides. A minireview

A minireview is presented on the ultracytochemical localization of membrane-bound guanylate cyclase (GC) in various tissues and in cultured cells after activation with three natriuretic peptides, the atrial natriuretic factor (ANF), the brain natriuretic peptide (BNP), and the C-type natriuretic peptide (CNP). GC, two subtypes of which have been recently identified, is the receptor for these peptides. The GC isoforms are differently stimulated by ANF, BNP and CNP. Under our experimental conditions, the natriuretic peptides were strong activators of GC since samples incubated without natriuretic peptides do not reveal any cyclase activity. The natriuretic peptide-stimulated GC activity was studied in rat kidney, lung, adrenal gland and neurohypophysis, in rabbit platelets, in lamb olfactory mucosa, and in rat C6 glioma cells. On the basis of the subcellular GC localization some additional functions of peptides are hypothesized.     

The nocturnal secretion of cardiac natriuretic peptides during obstructive sleep apnoea and its response to therapy with nasal continuous positive airway pressure

The nocturnal secretion profile of the newly identified natriuretic peptide (NP), brain natriuretic peptide (BNP), was studied in 14 patients with obstructive sleep apnoea syndrome (OSAS) (apnoea hypopnoea index: 60.5±3.4, mean±SE) during two separate nights before and during nasal continuous positive airway pressure (NCPAP) therapy. Plasma levels of NPs (atrial natriuretic peptides; ANP and BNP) were measured at 2-h intervals during sleep. Simultaneously, blood pressure was measured by a non-invasive method (Finapres^®, Ohmeda, Englewood, CO, USA) and urine was collected for determing volume and catecholamine levels. Urinary and serum sodium concentration were determined before and after the study. Eight non-snoring subjects were also studied for the investigation of normal nocturnal profiles of BNP levels. To understand the discrete secretion profiles of the two NPs during sleep, blood was sampled from an additional seven patients every 5 min over a 30-min period around 00.00 and 04.00 hours before NCPAP. In patients with OSAS, plasma BNP levels increased from the beginning of sleep (22:00 h) to the morning (06:00 h) before NCPAP therapy (P< 0.01, anova ). Baseline BNP levels were not significantly correlated with patient's clinical and poly- somnographic parameters. However, in the latter half of the sleep period (02:00–06:00 h), increases in BNP levels during the night before NCPAP therapy were significantly correlated with blood pressure elevations (systolic: r=0.784 P< 0.01, diastolic: r=0.587 P< 0.01) and with apnoea duration (r=0.582 P< 0.01). In normal subjects BP and BNP levels were not changed significantly during sleep. Plasma BNP levels were well correlated with concomitant ANP levels (P< 0.001). NCPAP therapy reduced ANP and BNP levels during sleep and in the morning (P< 0.01). Plasma levels of BNP at 5 min intervals before NCPAP therapy revealed few variations. On the other hand, ANP levels fluctuated over the 30-min period. Changes in BNP levels during sleep in the patients with OSAS may be related to blood pressure variations, but may be too small to play a significant physiological role in regulating diuresis in OSAS. Further work is required to determine the precise role of dual natriuretic system in cardiovascular load and natriuresis in OSAS.     

非体外循环下冠状动脉旁路移植围术期血浆脑钠肽释放及其相关性研究

背景：B型脑钠肽已成为心血管疾病诊断重要的血清标志物,作为心血管疾病危险因素分层的重要因子。 目的：分析冠状动脉旁路移植前后B型脑钠肽与各项血流动力学参数的关系。 方法：选择30例冠心病行冠脉旁路移植患者,分为左室射血分数≥ 50%心功能正常患者13例;左室射血分数< 50%心功能不全患者17例。观察患者移植前1 d、移植后7 h、移植后1,3,5,7 d血浆B型脑钠肽水平变化趋势,分析移植前后B型脑钠肽与心功能各项指标的相关关系。 结果与结论：左室射血分数≥ 50%组患者冠脉旁路移植前后血浆B型脑钠肽水平显著低于左室射血分数< 50%组;组内比较移植后血浆B型脑钠肽水平均显著高于移植前(P < 0.05或P < 0.001)。患者冠脉旁路移植前B型脑钠肽水平与纽约心脏病协会心功能分级、左房内径、左室内径呈正相关(r=0.61;r=0．34;r=0．67);与左室射血分数、心排血量呈负相关(r=-0.75;r=-0.70)。患者移植后B型脑钠肽峰值浓度与出院前纽约心脏病协会心功能分级、超声心动图左室舒张末期内径、肺动脉压力呈正相关(r=0.72;r=0.70;r=0.45)。结果说明冠心病患者冠脉旁路移植前血浆B型脑钠肽质量浓度与左心室射血分数及左心室舒张末期内径有很好的相关性,能准确反映冠脉旁路移植前后的心功能状态。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

Effects of estrogen replacement therapy on natriuretic peptides and blood pressure

OBJECTIVE: Estrogen replacement therapy (ERT) has been reported to affect blood pressure. Since natriuretic peptides have natriuretic and vasodilatory activity and also inhibit the renin-angiotensin-aldosterone system and lower blood pressure, it was hypothesized that the changes in blood pressure effected by ERT might be mediated via changes in natriuretic peptides. METHODS: Fifty-eight postmenopausal hysterectomized women were randomized in a double-blind, double-dummy study to receive either peroral estradiol valerate 2 mg/day or transdermal estradiol gel containing 1 mg estradiol/day for 6 months. Blood pressure was measured by using an automatic, oscillometric device. Plasma atrial natriuretic peptide (ANP), N-terminal fragment of proANP (NT-proANP), B-type natriuretic peptide (BNP), aldosterone, and renin were determined by radioimmunoassay. RESULTS: The mean decrease in diastolic blood pressure was -6 mmHg both in the peroral group (n = 26) (P = 0.002) and in the gel group (n = 27) (P = 0.001), and the corresponding decreases in systolic blood pressure were -4 mmHg (P = 0.070) and -7 mmHg (P = 0.028) in the sitting position. Plasma NT-proANP rose from 212 to 264 pmol/l (P = 0.001) on peroral ERT and from 240 to 292 pmol/l (P = 0.008) on transdermal ERT. No significant changes were observed in the plasma ANP, BNP, aldosterone, and renin levels. CONCLUSIONS: Both peroral and transdermal ERT result in elevated plasma levels of NT-proANP, indicating an activation of the natriuretic peptide system. This could explain, at least in part, the lowering of blood pressure during ERT.     

2型糖尿病血管病变时血浆ANP、BNP及CNP的变化及临床意义

目的：探讨血浆心钠素(ANP)、脑利钠肽(BNP)、C型利钠肽(CNP)在2型糖尿病血管病变时的变化及其临床意义。方法:应用酶联免疫吸附法(ELISA)测定正常对照组(9例)、2型糖尿病无血管病变组(34例)及2型糖尿病血管病变组(23例)血浆proANP、BNP fragment及NT-proCNP浓度，分析各组间血浆利钠肽水平的变化及相关因素。结果:2型糖尿病血管病变组血浆ANP、BNP明显高于另外2组（P<0.01），而血浆CNP明显降低（P<0.01），2型糖尿病血管病变组各亚组(微血管病变组、大血管病变组及微血管合并大血管病变组)间血浆利钠肽水平无明显差异（P>0.05）。2型糖尿病血管病变组血浆ANP与BNP间存在显著正相关（r=0.309, P<0.05），ANP与CNP（r=-0.374, P<0.05）以及BNP与CNP（r=-0.653, P<0.01）间存在显著负相关。结论:血浆ANP、BNP及CNP的联合检测可以作为简便、价廉、可靠的糖尿病血管病变的筛选指标。     

Natriuretic peptides in clinical practice

The natriuretic peptide (NP) system is primarily an endocrine system that maintains fluid and pressure homeostasis in healthy humans. The cardiac NP, ANP (atrial natriuretic peptide) and BNP (brain natriuretic peptide) are secreted by the heart in proportion to cardiac transmural pressures. The relationship between plasma levels of these peptides and "cardiac load" has led to their use as biomarkers of cardiac health with diagnostic and prognostic applications in a variety of disorders affecting the cardiovascular system. Elevated NP levels may serve as an early warning sign to help identify patients at a high risk of cardiac events. BNP and its N-terminal fragment (NT-BNP) are especially sensitive indicators for cardiac dysfunction and remodeling (correlate with severity) and play a role in the detection of coronary artery disease. The favorable biological properties of NP have also led to their use as therapeutic agents. Recombinant human ANP (carperitide) and BNP (nesiritide) are useful in the management od acutely decompensated heart failure.     

The natriuretic peptides: universal volume controllers

Since the discovery of the natriuretic effect of atrial natriuretic peptide (ANP), a family of other natriuretic peptides similar to ANP were isolated, including atriopeptin, vessel dilator, long-acting natriuretic peptide, urodilatin, and brain natriuretic peptide (BNP) to name a few. ANP was noted to possess natriuretic and diuretic properties that controlled increases in intravascular volume. ANP was also found to be elevated in conditions of increased intraocular pressure and biliary obstruction. BNP was found to be elevated in conditions of increased intracranial pressure, pointing towards its role in controlling cerebrospinal fluid volume. While at the cellular level, ANP controlled individual cell size. This makes the natriuretic peptides not only controllers of intravascular volume, but also modulators of a myriad of cavity volumes down to the control of individual cell volume.     

Correlation and prognostic utility of B-type natriuretic peptide and its amino-terminal fragment in patients with chronic kidney disease

This study compared the correlation and prognostic utility of B-type natriuretic peptide (BNP) and the N-terminal fragment of proBNP (NT-proBNP) in 171 outpatients with renal dysfunction. The NT-proBNP correlated well with BNP in all cases (r = 0.911; P pound .01), regardless of degree of renal impairment or type of left ventricular dysfunction. BNP and NT-proBNP concentrations (P < .005) and their ratios (P pound .01) increased as the glomerular filtration rate (GFR) declined, indicating a greater effect of GFR on NT-proBNP levels. Both natriuretic peptide levels were higher in patients with systolic dysfunction (P < .05) compared with patients with normal echocardiograms. In contrast, BNP and NT-proBNP levels were below the diagnostic cutoffs for congestive heart failure exacerbations in patients with normal heart function or diastolic dysfunction, with no statistical difference between these groups (P = .99). Both peptides are useful prognostic tools for predicting mortality and cardiac hospitalization in renal patients.     

HS-142-1, a novel non-peptide ANP antagonist, blocks the cyclic GMP production elicited by natriuretic peptides in PC12 and NG108-15 cells.

HS-142-1 is a novel non-peptide antagonist for atrial natriuretic peptide (ANP) receptor. The effect of HS-142-1 on the cyclic GMP production elicited by natriuretic peptides in neuronal cell lines, PC12 and NG108-15 was examined. Natriuretic peptides such as ANP, brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) enhanced cyclic GMP production in a dose-dependent manner. HS-142-1 inhibited cyclic GMP accumulation elicited by natriuretic peptides in a dose-dependent fashion in both cells. The results suggest that HS-142-1 will be an important tool for identification and understanding of the mechanisms by which natriuretic peptides act in nervous systems.     

Cardiac natriuretic peptide hormones during artificial cardiac pacemaker stimulation and left heart catheterization

Summary Brain natriuretic peptide (BNP) is synthesized and released predominantly in the ventricular myocardium whereas atrial natriuretic peptide (ANP) is produced mainly in the atria. This study evaluated whether artificial pacemaker stimulation or left heart catheterization results in specific changes in BNP and ANP plasma levels. Both BNP and ANP responded sensitively to changes in pacemaker stimulation (single-chamber pacemakers; pacing rates of 72 and 92/min) and during the left heart catheterization procedure. However, whereas higher pacing resulted in a more pronounced increase in plasma BNP levels, a stronger ANP release followed catheterization. This incongruous rise in ANP and BNP plasma concentrations points to at least partly independent mechanisms govering the release of BNP and ANP.Abbreviations ANP atrial natriuretic peptide - BNP brain natriuretic peptide     

利尿钠肽在诊断心力衰竭中的应用价值

探讨利尿钠肽的水平对心力衰竭（心衰）早期诊断的应用价值。采用放免法、ELISA法检测了129例心衰患者血浆中的心房利尿钠肽（ANP）、脑利尿钠肽（BNP）、N末端脑钠肽前体蛋白（NT-proBNP）水平,并与30例健康对照者进行了比较分析。结果显示,心衰患者血浆中的ANP、BNP、NT-proBNP显著高于健康对照组,且均随着NYHA分级的升高而逐渐增加,其含量在NYHA Ⅳ级时到达最高,心衰患者的血浆ANP、NT-proBNP水平与LVEF呈明显负相关。检测血浆中的ANP、BNP、NT-proBNP含量简便、快捷,可用于心衰诊断及NYHA分级判断。