成人先天性心脏病的血管紧张素Ⅱ、醛固酮和去甲肾上腺素激活及临床意义

目的探讨成人先天性心脏病（先心病）是否存在血管紧张素Ⅱ（AngⅡ）、醛固酮（ALD）和去甲肾上腺素（NE）激活及其临床意义。方法选取100例成人先心病患者,检测其AngⅡ、ALD和NE;另选取年龄及性别与之相匹配的30名健康体检成人作为对照组。结果成人先心病血循环中的AngⅡ（188.3±11.5）ng/L、ALD（546.1±42.3）pmol/L、NE（2.17±0.08）nmol/L与对照组比较明显增高（均P〈0.01）。3个亚组随着疾病严重程度的加重,神经内分泌的激活就越明显。结论成人先心病的AngⅡ、ALD和NE明显激活并具有慢性心力衰竭的特征,并与疾病的严重性密切相系。     

Univentricular heart in adults: report of nine cases with review of the literature

Nine patients with univentricular heart 17 years of age or older were followed up for a mean duration of 13 years (range 5 to 26 years). Five patients had type A and four patients had type C univentricular heart. Pulmonary stenosis was present in eight of nine patients. Palliative shunt surgery was performed in seven patients, ventricular septation was performed in one patient, and no surgical intervention was performed in one patient. Eight patients were in New York Heart Association functional class II and one patient was in New York Heart Association functional class III. Long term follow-up of these patients suggests that a selected group of adults with univentricular heart may achieve a relatively long survival and good functional class with conservative management.     

Non-Thyroidal-Illness-Syndrom (NTIS) bei Patienten mit prolongierter Beatmung

Background

The impact of non-thyroidal illness syndrome (NTIS) on ventilation time has not yet been investigated in detail. This study explores the possible correlation between existing NTIS and ventilation time.

Method

We assessed all patients in an intensive care unit (ICU) within a 6-year period who had undergone invasive mechanical ventilation and for whom fT₃, fT₄ and TSH levels were determined within the first 4 days and subsequently at least every 8 days. The primary outcome in this study was prolonged ventilation time, defined as being longer than 13 days.

Results

The study enrolled 264 patients. While 56 patients presented with normal thyroid hormone levels, 208 patients displayed decreased fT₃ levels. In the latter group 145 patients had normal fT₄ levels, while in 63 patients the fT₄ level was decreased. In that same group the TSH levels were normal in 189 patients and decreased in the remaining 19 patients. Compared with the “normal hormone level” study arm, the low T₃ group suffered from a significant increase in mortality, higher SAPS-II scores, longer ventilation time, and a longer stay in the ICU.

Conclusion

The presence of NTIS is a risk factor for prolonged ventilation time in ICU patients.     

心外管道与直接吻合全腔静脉-肺动脉连接术早期和中期疗效对比研究

目的比较心外管道与直接吻合全腔静脉-肺动脉连接术早期和中期疗效。方法选择2005年6月至2009年12月在广东省心血管病研究所行心外全腔静脉-肺动脉连接术的患者53例为研究对象，其中15例行下腔静脉-肺动脉直接吻合全腔静脉-肺动脉连接术（直接吻合组），38例行心外管道全腔静脉-肺动脉连接术（心外管道组）。随访（23．0±15．6）个月，比较两组患者的年龄、体质量、术前红细胞比容、血氧饱和度、M率分布等术前情况；术中体外循环和主动脉阻断时间；早期指标[术后早期失败率（死亡或撤除）、住院时间、外科加强监护病房（surgery intensive care unit，SICU）时间、机械通气时间、血氧饱和度、中心静脉压、术后红细胞比容、胸管引流时间、乳糜胸发生率及心律失常等其他并发症]及中期指标[中期病死率（死亡和纽约心脏协会心功能Ⅳ级）、心律失常、人工管道狭窄或梗阻及其他并发症]。结果（1）两组年龄、术前体质量、术前红细胞比容、血氧饱和度、M率分布、术中体外循环和主动脉阻断时间比较，差异无统计学意义（P〉0．05）。（2）直接吻合组术后胸管引流时间短于心外管道组，差异有统计学意义[（15．5±9．6）d眠（24．1±19．5）d，t=2．245，P=0．030]；两组其余早期临床疗效指标（住院时间、早期失败率、SICU时间、中心静脉压、术后红细胞比容、乳糜胸发生率、心律失常等其他并发症）比较，差异无统计学意义（P〉0．05）。（3）两组中期病死率比较，差异无统计学意义[8．3％（1／13）vs．5．7％（2／35），P〉0．05]。直接吻合组患者术后计算机断层扫描重建显示下腔静脉一主肺动脉吻合口血流通畅无梗阻．无狭窄。结论下腔静脉一肺动脉直接吻合全腔静脉一肺动脉连接术适合满足Fontan类手术条件，同时心脏解剖合适的患者。手术可以获得心外管道全腔静脉肺动脉连接术良好的临床效果，同时避免了使用外源性材料。     

Risks and Benefits of Combined Maze Procedure for Atrial Fibrillation Associated With Organic Heart Disease

Objectives. This study sought to identify the risks and benefits of adding the maze procedure in patients with atrial fibrillation (AF) undergoing operation for underlying organic cardiac disorders.Background. Persistent AF often leaves patients symptomatic even after otherwise successful cardiac surgery.Methods. Fifty-one patients undergoing valvular operation and the maze procedure (n = 43) or repair of congenital anomalies (n = 8) combined with the maze procedure were compared with 51 patients (control group) matched for underlying diseases and procedures except for the maze operation. Each group, including 31 patients with a concomitant tricuspid annuloplasty and 12 undergoing reoperation, were similar in age, duration of arrhythmia, degree of cardiomegaly and New York Heart Association functional class.Results. Patients undergoing the maze procedure had longer cardiopulmonary bypass time (213 vs. 144 min, p < 0.0001), longer cardiac arrest (134 vs. 93 min, p < 0.0001) and greater blood loss with longer respiratory care (39 vs. 18 h, p = 0.021) and intensive care unit stay but no mortality. No significant differences were found in catecholamine or transfusion requirements immediately after operation. Sustained AF was much less frequent in the maze group (12% at 1 year) than the control group (86%, p < 0.0001), with an average follow-up period of 32 months (range 25 to 42). Atrial contraction was documented in 41 (80%) and 40 (78%) patients for right and left ventricular filling, respectively, after the maze procedure, resulting in a significantly smaller cardiac size and improved functional capacity. Medication was discontinued in seven patients in the maze group compared with two in the control group.Conclusions. Improved restoration of atrial rhythm and contraction with combined maze operation appeared to justify the increased operative time and complexity and postoperative care.     

Outcome of pregnancy in women with congenital shunt lesions

OBJECTIVE: To evaluate the outcome of pregnancy in women with congenital shunt lesions. SETTING: Retrospective study in a tertiary care centre. METHODS: Pregnancy history was obtained by a standardised questionnaire and medical records were reviewed. PATIENTS: 175 women were identified, at a mean (SD) age of 42 (14) years. Pregnancies occurred in 126 women: 50 with an atrial septal defect, 22 with a ventricular septal defect, 22 with an atrioventricular septal defect, 19 with tetralogy of Fallot, and 13 with other complex shunt lesions. RESULTS: 309 pregnancies were reported by 126 woman (2.5 (1.6) pregnancies per woman). The shortening fraction of the systemic ventricle was 40 (8)%, and 98% were in New York Heart Association class I-II at last follow up. Spontaneous abortions occurred in 17% of pregnancies (abortion rate, 0.4 (0.9) per woman). Gestational age of the 241 newborn infants was 8.8 (0.8) months. There were no maternal deaths related to pregnancy. Pre-eclampsia and embolic events were observed in 1.3% and 0.6%, respectively of all pregnancies. Women with complex shunt lesions more often underwent caesarean section (70% v 15-30%, p = 0.005) and gave birth to smaller babies for equivalent gestation (2577 (671) g v 3016 (572) to 3207 (610) g, p < 0.05). The recurrence risk of congenital heart disease was 2.5%. CONCLUSIONS: The outcome of pregnancy is favourable in women with congenital shunt lesions if their functional class and their systolic ventricular function are good. Such patients can be reassured.     

Appropriate Heart Rate in a Patient with Repaired Tetralogy of Fallot

Appropriate heart rate in a failing pulmonary ventricle remains unknown, particularly in congenital heart disease with unique hemodynamics. A 71-year-old male with repaired tetralogy of Fallot and a pacemaker for a sinus node dysfunction suffered from heart failure symptoms with preserved left ventricular function. Simply changing the pacemaker’s lower rate from 60 to 75 bpm, New York Heart Association classification improved from III to II, and hemodynamic parameters drastically improved. We regarded this case as informative. Appropriate heart rate could be higher in congenital patients with failing right and non-failing left ventricles than in adults with malfunctioning LV.     

Influence of carvedilol on hospitalizations in heart failure: incidence, resource utilization and costs. U.S. Carvedilol Heart Failure Study Group

BACKGROUND: Carvedilol reduces disease progression in heart failure, but to our knowledge, its effects on hospitalizations and costs have not been evaluated. OBJECTIVES: We examined the effects on hospitalization frequency and costs in the U.S. Carvedilol Heart Failure Trials Program. This program consisted of four concurrent, multicenter, double-blind, placebo-controlled studies involving 1,094 patients with New York Heart Association class II to IV heart failure, which treated patients with placebo or carvedilol for up to 15 months (median, 6.5 months). METHODS: Detailed resource utilization data were collected for all hospitalizations occurring between randomization and the end of follow-up. In-patient care costs were estimated based on observed levels of resource use. RESULTS: Compared with placebo, carvedilol reduced the risk of hospitalization for any reason by 29% (p = 0.009), cardiovascular hospitalizations by 28% (p = 0.034) and heart failure hospitalizations by 38% (p = 0.041). Carvedilol also decreased the mean number of hospitalizations per patient (for cardiovascular reasons 30% [p = 0.02], for heart failure 53% [p = 0.03]). Among hospitalized patients, carvedilol reduced severity of illness during hospital admission, as reflected by shorter length of stay and less frequent use of intensive care. For heart failure hospital admissions, carvedilol decreased mean length of stay by 37% (p = 0.03) and mean number of intensive care unit/coronary care unit days by 83% (p = 0.001), with similar effects on cardiovascular admissions. As a result, estimated inpatient care costs with carvedilol were 57% lower for cardiovascular admissions (p = 0.016) and 81% lower for heart failure admissions (p = 0.022). CONCLUSIONS: Carvedilol added to angiotensin-converting enzyme inhibition reduces hospitalization risk as well as severity of illness and resource utilization during admission in patients with chronic heart failure.     

Outcome of cardiac surgery in adults with congenital heart disease: A single center experience

ObjectivesAdult survivors with congenital heart diseases represent a large and growing population, yet the published data does not represent the magnitude of their needs specifically in the Middle East. We aimed to review our experience at King Faisal Heart Center, Riyadh, Saudi Arabia for the outcome of adult patients with congenital heart disease who underwent either primary or redo surgery.MethodsA retrospective study at a tertiary care hospital. All patients who underwent surgery either as the first surgery or as a reoperation for congenital heart disease aged >16 years old at the time of cardiac surgery in the period between January 1, 2008 and January 1, 2013. We looked for incidence of postoperative bleeding, arrhythmias, acute kidney injury, neurological complications, duration of mechanical ventilation, hospital and intensive care unit (ICU) stay. Additionally, we assessed the mortality and 1- and 5-year survival.ResultsNinety-eight patients were included in our study. Fifty-two (53%) were females and 46 (47%) were males, with a mean age of 26 ± 8.4 years and a mean weight of 62 ± 22.8 kg. Forty-nine patients (50%) required redo surgery. Ten patients (10%) suffered from postoperative bleeding. Eight patients (8%) had postoperative arrhythmias, of which two patients required permanent pacemaker insertion. Three patients (3%) had postoperative acute kidney injury and seven patients (7%) suffered from neurological complications. The mean duration of ventilation was 1.3 ± 2 days, with a mean ICU and hospital stay of 3.7 ± 3 days, and 10 ± 7 days, respectively. The overall mortality rate in our series was 4% with a 1–5-year survival of 96%.ConclusionAdult patients with congenital heart disease are prone to immediate postoperative multisystem complications, yet the majority of them are reversible. Their 1- and 5-year survival rate is excellent. Further follow up studies are required.     

Adult cyanotic congenital heart disease: surgical experience.

Cyanotic congenital heart diseases constitute about 10 percent of total congenital heart disease cases in adults in the developing world. Prolonged cyanosis and old age adversely affect the outcome of surgery, thus posing a challenge to the cardiac surgeons. This study was conducted to assess the feasibility, safety and outcome of surgery in this group of patients. From January 1991 to December 1997, a total of 303 patients, aged 14 to 54 years (mean 19.8 +/- 1.5 years) with diagnosis of various cyanotic congenital heart diseases were operated at our institute. There were 210 males (69.3%). Two hundred and forty-seven patients (81.5%) had tetralogy of Fallot's physiology, 51 patients (16.8%) had single ventricle physiology and five (1.6%) had other lesions. Sixty-six patients (21.7%) had pre-operative complications such as haemoptysis, epistaxis, cerebrovascular accidents, brain abscess and infective endocarditis. Sixty patients (19.8%) had previous palliative shunts and 26 patients (8.5%) had coil embolisation of major aortopulmonary collaterals prior to surgery; 229 patients (75.5%) underwent biventricular repair, 52 (17.1%) had univentricular repair, 22 (7.7%) had palliative shunts and one patient had open ligation of a major aortopulmonary collateral in addition. In-hospital mortality was 3.3 percent. Follow-up period ranged from five months to seven years (mean 4.2 +/- 1.8 years). There were two late deaths. Of the 291 survivors, 11 were lost to follow-up. Two hundred and fifty-eight patients (92.1%) are in New York Heart Association class I. Significant residual defects warranting reoperation were present in four patients (1.3%). It is concluded that congenital heart surgery in older cyanotic patients can be performed safely with satisfactory results.     

Elevated circulating levels of inflammatory cytokines and bacterial endotoxin in adults with congenital heart disease

Chronic heart failure is a state of immune activation, and endotoxin is a potential trigger for cytokine production. Our aim was to study whether immune activation and endotoxemia occur in adults with congenital heart disease. We prospectively measured tumor necrosis factor (TNF)-alpha, soluble TNF receptors (sTNFR-1, sTNFR-2), interleukin-6, interleukin-10, endotoxin, and soluble CD14 levels in 52 consecutive adults with congenital heart disease (age 34 +/- 2 years [mean +/- SEM]) and 18 healthy controls (age 31 +/- 1 years). A variety of congenital heart lesions were studied: single ventricle physiology (n = 15), systemic right ventricle (n = 7), tetralogy of Fallot (n = 20), and "other" congenital heart disease (n = 10). Patients were subgrouped into asymptomatic (New York Heart Association [NYHA] class I, n = 11), mild (NYHA class II, n = 30), and moderate/severe (NYHA class III/IV, n = 11) categories. Patients had elevated TNF and interleukin-6 levels compared with controls (TNF 2.8 vs 2.1 pg/ml, p <0.05; interleukin-6 8.5 vs 5.7 pg/ml, p <0.001). TNF levels were higher in patients with moderate/severe symptoms compared with patients who were asymptomatic or had mild symptoms (p <0.05). Soluble TNFR-1 levels related directly to the degree of systemic ventricular impairment (p <0.05). There were no significant differences in sTNFR-1, sTNFR-2, interleukin-10, or sCD14 levels between patients and controls. Endotoxin levels were greater in patients with congenital heart disease versus controls (0.40 vs 0.26 endotoxin units/ml, p <0.0001). Thus, adults with congenital heart disease have elevated levels of inflammatory cytokines and bacterial endotoxin, which relate to functional status. Congenital heart disease in adults may be amenable to novel anti-inflammatory therapies in selected patients.     

Patients with pulmonary arterial hypertension in clinical trials: who are they?

Results from clinical trials serve as the basis for approval of therapies by regulatory agencies as well as for treatment decisions by clinicians. But these findings are relevant only to patients who are similar to the ones enrolled into the trials. This is germane to clinical trials on pulmonary arterial hypertension (PAH) because the disease is uncommon but highly heterogeneous and results can easily be misapplied. The characteristics of patients entering the trials are largely determined by inclusion/exclusion criteria, with the result that most participants have idiopathic, connective tissue disease- and congenital heart disease-related PAH. Earlier trials enrolled patients mainly with New York Heart Association functional class III and IV disease and with severe pulmonary hemodynamic abnormalities. Because it has been the major outcome variable in most of the trials, eligibility is also dependent on six-minute-walk distance, ensuring that patients are moderately but not too severely functionally impaired, thereby maximizing the likelihood of detecting a favorable response to therapy. More recent trials have enrolled less ill patients, with more patients with New York Heart Association functional class II disease, less severe hemodynamic abnormalities, and more stability over time. This reflects, in part, ethical concerns about enrolling sicker patients into placebo-controlled trials. Trials have mainly enrolled white females in their 40s and 50s and have consistently excluded non-WHO group 1 forms of pulmonary hypertension. These characteristics must be carefully considered when applying the findings of pulmonary hypertension trials in clinical practice.     

One-year mortality among unselected outpatients with heart failure.

OBJECTIVE: To estimate 1-year mortality and prognostic factors in unselected outpatients with heart failure, and to compare the observed mortality with the estimates of the primary care physicians. METHODS AND RESULTS: Four hundred and eleven consecutive patients with heart failure New York Heart Association (NYHA) class II-IV (mean population age 75 years, 56% males) were enrolled in 71 primary care offices throughout Switzerland. During a mean follow-up period of 1.4 years, 68 patients had died. One-year total mortality was 12.6% compared to 4.3% in the underlying Swiss population (standardized mortality ratio 3.0). Among patients with heart failure NYHA II, III and IV, mortality was 7.1%, 15.0% and 28.0%, respectively. In multivariate Cox regression, statistically significant (P<0.05) predictors of mortality were NYHA class (NYHA III: risk ratio [RR]=1.6; NYHA IV: RR=2.2), recent hospital stay for heart disease (RR=2.3), creatinine>120 micromol.l(-1) (RR=1.8) systolic blood pressure<100 mmHg (RR=2.4), heart rate>100 min(-1) (RR=2.7), age (per 10 years, RR=1.6) and female gender (RR=0.49). Among patients with reduced left ventricular ejection fraction, 1-year mortality was 14.3%, and predictors were similar except that female gender was no longer associated with reduced mortality. Primary care physicians significantly overestimated 1-year mortality (estimated mortality 25.9% vs observed mortality 12.6%,P =0.001). CONCLUSIONS: Unselected outpatients with heart failure have a poor prognosis, particularly those with advanced heart failure and a recent hospital stay for heart disease. Primary care physicians are aware of the high mortality of this growing patient population.     

Patients with heart failure in primary health care: effects of a nurse-led intervention on health-related quality of life and depression

AIMS: To determine the effects of a nurse-led intervention designed to improve self-management of patients with heart failure in a primary health care setting regarding health-related quality of life and depression. METHODS: Patients at eight primary health care centres were screened by the Diagnosis Related Groups registry for the diagnosis of heart failure and eligibility for a cluster randomised study. A total of 153 patients were included (n=78 in the intervention group, 54% males, mean age 79 years, 59% in New York Heart Association class III-IV). The intervention involved patient and family education about heart failure and self-management and monthly telephone follow-up during 12 months by a primary health care nurse. RESULTS: The effects of the nurse-led intervention were limited. Significant differences were found in the physical dimension measured by the SF-36 health survey, and in depression measured by the Zung Self-rating Depression Scale. In comparison within groups at the 3 and 12-month follow-up, the intervention group significantly maintained their health-related quality of life measured by the SF-36 health survey, and their experience of depression measured by the Zung Self-rating Depression Scale to a greater extent than in the control group, especially among women. CONCLUSION: A nurse-led intervention directed toward patients with heart failure in a primary health care setting resulted in limited effects between the groups, although the physical and mental status were retained during 12 months of follow-up to a greater extent than in the control group.     

Understanding the Etiology of Heart Failure Among the Rural Poor in Sub-Saharan Africa: A 10-Year Experience From District Hospitals in Rwanda

Background

Heart failure is a significant cause of morbidity and mortality in sub-Saharan Africa. Our understanding of the heart failure burden in this region has been limited mainly to registries from urban referral centers. Starting in 2006, a nurse-driven strategy was initiated to provide echocardiography and decentralized heart failure care within noncommunicable disease (NCD) clinics in rural district hospitals in Rwanda.

Child-Pugh class, nutritional indicators and early liver transplant outcomes.

BACKGROUND/AIMS: Patients with chronic liver disease undergoing liver transplantation have reduced body fat and muscle mass. The extent to which nutritional indicators and Child-Pugh class are predictive of postoperative outcome in adults is unclear. The aims of this study were to determine in adult patients undergoing transplant 1) the influence of preoperative Child-Pugh class and nutritional indicators on early transplant outcomes and one-year survival, 2) the relationship between nutritional indicators and Child-Pugh class and disease type. This study included 80 patients (1990-1994). METHODOLOGY: The nutritional indicators utilized were grip strength, triceps skinfold thickness and uncorrected mid-arm muscle area. Measured outcomes were ventilator time, intensive care stay, postoperative hospital stay and one-year survival. RESULTS: Early morbidity was determined in survivors. Child-Pugh class C patients required longer ventilation and spent more time in the intensive care unit than Child-Pugh classes A and B. No significant relationships were found for length of hospital stay. Relationships between the nutritional indicators (when controlled for Child-Pugh class) and early morbidity could not be determined due to insufficient data. No relationship was established between one-year survival and Child-Pugh class or the nutritional indicators. Grip strength and mid-arm muscle area were lower in the patients in Child-Pugh classes B and C. Parenchymal liver disease was associated with lower grip strength and mid-arm muscle area when compared to cholestatic disease. CONCLUSIONS: Child-Pugh class C is associated with greater early postoperative morbidity. Advanced Child-Pugh class is also associated with diminished muscle status and parenchymal disease.     

Robotically controlled video-assisted port-access mitral valve surgery

From 1997 to 2000, 221 patients underwent mitral valve surgery through a mini-thoracotomy, using a port-access endovascular cardiopulmonary bypass system in 38 and a transthoracic clamp in 183. In 120 patients, exposure of the mitral valve was facilitated by an endoscope attached to a voice-controlled robotic arm (AESOP 3000). The mitral valve was repaired in 26 patients and replaced in 195; 24 were redo cases. Operating time was 3.5 +/- 1.2 hours, aortic crossclamp time was 58 +/- 16 minutes, intensive care unit stay was 22 +/- 7 hours, and hospital stay was 6.4 +/- 1.2 days. Median postoperative blood loss was 332 +/- 104 mL. There was 1 hospital death. On follow-up at 16.4 +/- 12.2 months, there was no late death or reoperation. New York Heart Association functional class improved from 2.6 +/- 0.5 to 1.4 +/- 0.8. Use of video and robotic assistance minimized incision length and allowed visualization of the whole mitral valve apparatus. The transthoracic clamp facilitated aortic crossclamping and injection of cardioplegia. These findings indicate that the procedure is safe and effective and suggest advantages over conventional surgery in terms of cost, cosmesis, blood loss, postoperative discomfort, intensive care unit and hospital stay.     

Five- to fifteen-year follow-up after Fontan operation.

BACKGROUND. The purpose of this study was to estimate survival and quality of outcome and assess factors associated with outcome for patients out 5 to 15 years from their Fontan operation. METHODS AND RESULTS. We studied 352 patients who had the Fontan operation prior to 1985. The overall 1-, 5-, and 10-year survival was 77%, 70%, and 60%, respectively. The following factors were significantly associated with lower survival: univentricular heart or complex congenital anomalies other than tricuspid atresia, early calendar year of operation, heterotaxia syndromes, early age at operation, increased pulmonary artery pressure, atrioventricular valve dysfunction, and higher (worse) New York Heart Association class. Reoperations were necessary for 103 of the 352 patients. At least 20% of the survivors have or have had cardiac arrhythmias requiring antiarrhythmic medication or mechanical pacemaker insertion. Between 7% and 10% of the patients have had or had protein-losing enteropathy/hypoproteinemia. At 5 years postoperatively, 122 patients (34.7%) were alive with a better New York Heart Association functional classification than preoperatively. Fifty-eight patients (16.5%) were alive and in the same functional classification, but 126 (35.8%) died within the first 5 years or were in a worse functional classification. Thirty-nine patients were doing excellently and 29 patients poorly 5 years after the operation. Of the surviving patients, 43% can do as much exercise as their peers, whereas 3% are incapable of exercise. CONCLUSIONS. To assure good functional long-term outcome in addition to survival, clinicians must exclude from selection for Fontan operation patients known to be at high risk for death or poor outcome.     

Left ventricular function at rest and during exercise in congenital complete heart block: A radionuclide angiographic evaluation

This study evaluates intrinsic cardiac performance during upright exercise in patients with congenital complete heart block. Left ventricular ejection fraction and volume were measured at rest and peak upright exercise with radionuclide angiography in 5 patients aged 11 to 39 years with congenital complete heart block: 4 were in New York Heart Association class I and 1 was in class II. The resting cardiac output was maintained at a normal level by an increase in end-diastolic volume rather than by a decrease in end-systolic volume. The left ventricular ejection fraction was normal at rest in all patients, but an abnormal response to exercise was noted in 3 patients. There was no appreciable change in the end-diastolic volume during exercise. Thus, patients with congenital complete heart block utilize the Starling mechanism to maintain normal resting cardiac output, but the response to exercise is usually abnormal even in the absence of symptoms.     

Utility of N-terminal pro-brain natriuretic peptide for the diagnosis of heart failure

BACKGROUND: The goal of this study was to evaluate the utility of plasma N-terminal pro-brain natriuretic peptide for the diagnosis of heart failure in patients presenting with shortness of breath. METHODS AND RESULTS: We measured plasma levels of N-terminal pro-brain natriuretic peptide in 119 patients presenting with shortness of breath. The patients were divided into two groups based on the Framingham criteria and echocardiographic results--those with heart failure and those not in heart failure. Plasma levels of N-terminal pro-brain natriuretic peptide were compared in the two groups. The mean N-terminal pro-brain natriuretic peptide concentration in patients with heart failure (n=73) was higher than that in those not in heart failure (389+/-148 fmol/ml v. 142+/-54 fmol/ml, p<0.001). N-terminal pro-brain natriuretic peptide values increased significantly as the functional severity of heart failure increased (p<0.001). The mean N-terminal pro-brain natriuretic peptide levels were 261+/-34 fmol/ml for patients in New York Heart Association functional class I, 300+/-161 fmol/ml for patients in New York Heart Association functional class II, 427+/-103 fmol/ml for patients in New York Heart Association functional class III and 528+/-170 fmol/ml for patients in New York Heart Association functional class IV. Using a cut-off value of 200 fmol/ml, the sensitivity of N-terminal pro-brain natriuretic peptide was 97%, specificity was 89% and accuracy for differentiating heart failure from other causes of shortness of breath was 93%. CONCLUSIONS: Our results suggest that N-terminal pro-brain natriuretic peptide can be reliably used for the diagnosis of heart failure in an outpatient setting, and this will improve the ability of clinicians to differentiate patients with shortness of breath due to heart failure from those with other causes of shortness of breath.