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Incident pulmonary arterial hypertension was underrepresented in most pulmonary hypertension registries and may have a different disease profile to prevalent disease.To determine the characteristics and outcome of a purely incident, treatment-naive cohort of idiopathic, heritable, and anorexigen-associated pulmonary arterial hypertension and to determine the changes in presentations and survival over the past decade in the United Kingdom and Ireland.All consecutive newly diagnosed patients from 2001 to 2009 were identified prospectively.A total of 482 patients (93% idiopathic, 5% heritable, and 2% anorexigen-associated pulmonary arterial hypertension) were diagnosed, giving rise to an estimated incidence of 1.1 cases per million per year and prevalence of 6.6 cases per million in 2009. Younger patients (age ≤ 50 yrs) had shorter duration of symptoms, fewer comorbidities, better functional and exercise capacity, higher percent diffusing capacity of carbon monoxide, more severe hemodynamic impairment, but better survival compared with older patients. In comparison with the earlier cohorts, patients diagnosed in 2007-2009 were older, more obese, had lower percent diffusing capacity of carbon monoxide,(,) and more comorbidities, but better survival. Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) equation, REVEAL risk score, and Pulmonary Hypertension Connection Registry survival equation accurately predicted survival of our incident cohort at 1 year.This study highlights the influence of age on phenotypes of incident pulmonary arterial hypertension and has shown the changes in demographics and epidemiology over the past decade in a national setting. The results suggest that there may be two subtypes of patients: the younger subtype with more severe hemodynamic impairment but better survival, compared with the older subtype who has more comorbidities.

Iron deficiency is known to be common and detrimental in chronic left heart failure, where parenteral iron treatment has been shown to improve exercise capacity, New York Heart Association functional class and patient wellbeing. There is now increasing interest in the role of iron in the natural history of pulmonary arterial hypertension (PAH). Iron availability influences the pulmonary vasoconstrictor response to hypoxia and accumulating evidence indicates that iron deficiency is prevalent in idiopathic and heritable forms of PAH, iron status being related to exercise capacity, symptoms and poorer survival in patients with idiopathic PAH (IPAH). Potential mechanisms behind iron deficiency in IPAH include inhibition of dietary iron uptake by the master iron regulator hepcidin. High hepcidin levels underlie the anaemia of chronic disease. Possible stimuli of the observed high levels of hepcidin in IPAH include dysfunctional bone morphogenetic protein receptor type II signalling and inflammation. Iron status may influence outcomes through modulation of the pulmonary circulation as well as myocardial and skeletal muscle function. Two parallel studies, from our centre (Hammersmith Hospital, London, UK) and others in the UK and Amsterdam (the Netherlands), investigating the safety and potential benefit of iron supplementation in patients with PAH are currently under way.

Several prognostic variables have previously been identified in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Specific medical conditions have also been associated with the development and prognosis of CTEPH. Using a national registry, the current authors have assessed the prognostic value of a larger number of variables and have also attempted to validate the clinical importance of previously identified aetiological factors. Baseline information for all 469 CTEPH patients diagnosed in the UK pulmonary hypertension service between January 2001 and June 2006 was collected from hospital records. Although univariate analysis confirmed the prognostic importance of pulmonary resistance, in multivariate analysis gas transfer and exercise capacity predicted pulmonary endarterectomy perioperative mortality. Cardiac index and exercise capacity independently predicted outcome in patients with nonoperable disease. Previous splenectomy was noted in 6.7% of patients, being significantly more common in patients with nonoperable than operable disease (13.7 versus 3.6%). Medical risk factors were not found to predict mortality. In a large national cohort, predictors of outcome in patients with both operable and nonoperable chronic thromboembolic pulmonary hypertension have been identified. These may be useful in planning treatment. The aetiological importance of previously identified medical risk factors has been confirmed, although the current authors were unable to validate their prognostic strength.

Objective To assess whether a pragmatic policy of perioperative β-blockade, with metoprolol, reduced the 30-day cardiovascular morbidity and mortality and reduced the length of hospital stay in average patients undergoing infrarenal vascular surgery. Methods This was a double-blind randomized placebo-controlled trial that occurred in vascular surgical units in four UK hospitals. Participants were 103 patients without previous myocardial infarction who had infrarenal vascular surgery between July 2001 and March 2004. Interventions were oral metoprolol (50 mg twice daily, supplemented by intravenous doses when necessary) or placebo from admission until 7 days after surgery. Holter monitors were kept in place for 72 hours after surgery. Results Eighty men and 23 women (median age, 73 years) were randomized, 55 to metoprolol and 48 to placebo, and 97 (94%) underwent surgery during the trial. The most common operations were aortic aneurysm repair (38%) and distal bypass (29%). Intraoperative inotropic support was required in 64% and 92% of patients in the placebo and metoprolol groups, respectively. Within 30 days, cardiovascular events occurred in 32 patients, including myocardial infarction (8%), unstable angina (9%), ventricular tachycardia (19%), and stroke (1%). Four (4%) deaths were reported. Cardiovascular events occurred in 15 (34%) and 17 (32%) patients in the placebo and metoprolol groups, respectively (unadjusted relative risk, 0.94; 95% confidence interval, 0.53-1.66; adjusted [for age, sex, statin use, and aortic cross-clamping] relative risk, 0.87; 95% confidence interval, 0.48-1.55). Time from operation to discharge was reduced from a median of 12 days (95% confidence interval, 9–19 days) in the placebo group to 10 days (95% confidence interval, 8-12 days) in the metoprolol group (adjusted hazard ratio, 1.71; 95% confidence interval, 1.09–2.66; P Conclusions Myocardial ischemia was evident in a high proportion (one third) of the patients after surgery. A pragmatic regimen of perioperative β-blockade with metoprolol did not seem to reduce 30-day cardiovascular events, but it did decrease the time from surgery to discharge.

Aim The treatment of patients with pulmonary arterial hypertension remains a challenge. We set out to investigate the use of sildenafil, a selective inhibitor of phosphodiesterase type 5, in patients with this disease. Methods and results Ten patients (8 females, mean age 34.5±3.3 years) with pulmonary hypertension underwent right heart catheterisation with vasodilator testing using incremental doses of intravenous sildenafil without adverse events. All patients were subsequently commenced on oral sildenafil 50 mg t.d.s. Nine patients had repeat right heart catheterisation 3 months after the commencement of oral therapy. There was a significant reduction in mean pulmonary artery pressure (from 55.8±5.9 to 50.4±6.1 mmHg, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(p=0.038\) \end{document}) and pulmonary vascular resistance (from 10.1±1.7 to 8.6±1.5 Wood units, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(p=0.009\) \end{document}), and an increase in cardiac output (from 4.7±0.3 to 5.0±0.4 l/min, \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(p=0.15\) \end{document}). Furthermore, there was a significant increase in the 6-minute walk test, a mean of 112 m. In response to a quality-of-life questionnaire, patients indicated marked clinical improvement on sildenafil. Sildenafil was discontinued in 1 patient due to a transient visual disturbance. The only patient previously awaiting transplantation was removed from the active transplantation list. Conclusions Sildenafil is well tolerated in its intravenous and oral forms and appears to improve both pulmonary haemodynamics and the clinical status of patients with pulmonary hypertension after 3 months of oral therapy.

Background Opioids are commonly used to treat dyspnoea in palliative medicine but there has been no formal evaluation of the evidence for their effectiveness in the treatment of dyspnoea. A systematic review was therefore carried out to examine this. Methods The criteria for inclusion required that studies were double blind, randomised, placebo controlled trials of opioids for the treatment of dyspnoea secondary to any cause. The methods used to identify suitable studies included electronic searching of the literature, hand searching of the literature, and personal contact with relevant individuals and organisations. Random effects meta-analyses were performed on all included studies and on various subgroups (studies involving nebulised opioids or patients with chronic obstructive pulmonary disease (COPD)). Subgroups were compared using meta-regression. Some studies included in the systematic review could not be included in the meta-analysis because insufficient data were presented. Results Eighteen studies fulfilled the criteria for the review. The meta-analysis showed a statistically significant positive effect of opioids on the sensation of breathlessness (p=0.0008). Meta-regression indicated a greater effect for studies using oral or parenteral opioids than for studies using nebulised opioids (p=0.02). The subgroup analysis failed to show a positive effect of nebulised opioids on the sensation of breathlessness. The results of the subgroup analysis of the COPD studies were essentially similar to the results of the main analysis. Conclusion This review supports the continued use of oral and parenteral opioids to treat dyspnoea in patients with advanced disease. There are insufficient data from the meta-analysis to conclude whether nebulised opioids are effective, but the results from included studies that did not contribute to the meta-analysis suggest that they are no better than nebulised normal saline.

Pulmonary arteriovenous malformations (PAVMs) carry significant risks [1, 2]. Pulmonary arterial blood passing through these right-to-left shunts cannot be oxygenated, leading to hypoxaemia, with arterial oxygen tension and arterial oxygen saturation ( S a,O2) inversely related to the size of the shunt fraction. The fragile wall of the PAVM sac may rupture, leading to haemoptysis or haemothorax [3]. In addition, the absence of a filtering capillary bed allows particulate matter to reach the systemic circulation where it impacts in other capillary beds, including those of the cerebral circulation, resulting in embolic cerebrovascular accidents and cerebral abscesses. In a recent series of 219 patients that corrected for ascertainment bias, the rates for ischaemic stroke and cerebral abscess were 11.3% and 9%, respectively, with risks unrelated to PAVM severity or symptoms [4]. Treatment of PAVMs by embolisation is an effective means of reducing lifetime risks of paradoxical embolic stroke and cerebral abscess [4], improving oxygenation [1, 5, 6], and treating PAVM-induced haemoptysis [3, 7]. Embolisation usually carries minimal risk in expert hands and, as a result, is generally offered to patients with PAVMs of a size amenable to embolisation, irrespective of the presence of respiratory symptoms. PAVMs themselves have a lower vascular resistance than that of the surrounding normal lung, due to the absence of a microvascular network of capillary vessels. However, most individuals with PAVMs have underlying hereditary …

Aims To investigate the response to inhaled prostacyclin in patients with primary and secondary pulmonary hypertension and to compare its effects to those of intravenous prostacyclin and inhaled nitric oxide. Methods and results Twelve patients with pulmonary hypertension (seven primary and five secondary) were studied. All patients had a pulmonary artery balloon flotation catheter inserted into the proximal pulmonary artery and radial arterial line. Prostacyclin was nebulized with 81. min−1 of oxygen and administered in doses increasing from 15 to 50 ng. kg−1. min−1 via a facemask. Eight of these patients also received intravenous prostacyclin in doses of 1 to 5 ng.kg−1.min−1 and nitric oxide in doses of 10 to 100 ppm via a facemask. Haemodynamic measurements were taken during each treatment. In the 12 patients, nebulized prostacyclin produced a significant reduction in mean pulmonary artery pressure from 56±5 to 45±4 mmHg ( P =0·0001). The pulmonary vascular resistance decreased by 38% from 964±169 to 595±116 dyne s−1.cm−5 ( P =0·0001). Direct comparison with inhaled nitric oxide and intravenous prostacyclin in eight patients demonstrated that nebulized prostacyclin produced a greater fall in mean pulmonary artery pressure than the other two agents without any significant effect on systemic arterial pressure. Conclusion Nebulized prostacyclin appears to be more effective at reducing pulmonary artery pressure in patients with pulmonary hypertension when compared to intravenous prostacyclin and inhaled nitric oxide. This could have important clinical implications for the management of patients with pulmonary hypertension.

OBJECTIVE--To assess relations between right ventricular pressure measured with a high fidelity transducer tipped catheter and the characteristics of tricuspid regurgitation recorded with Doppler echocardiography. DESIGN--A prospective non-randomised study of patients with severe pulmonary hypertension referred for consideration of lung transplantation. SETTING--A tertiary referral centre for cardiac and pulmonary disease, with facilities for invasive and non-invasive investigation, and assessment for heart and heart-lung transplantation. PATIENTS--10 patients with severe pulmonary hypertension being considered for lung transplantation. ENDPOINTS--Peak right ventricular, pulmonary artery, and right atrial pressures; peak positive and negative right ventricular dP/dt; peak Doppler right ventricular-right atrial pressure drop; Doppler derived peak positive and negative right ventricular dP/dt; and time intervals of Q to peak right ventricular pressure and to peak positive and negative right ventricular dP/dt. RESULTS--The mean (SD) pulmonary artery systolic pressure was 109 (29) mm Hg. The peak Doppler right ventricular-right atrial pressure drop underestimated peak right ventricular pressure by 38 (21) mm Hg, and by 21 (18) mm Hg when the Doppler value was added to the measured right atrial pressure (P values < 0.05). This discrepancy was greater for higher pulmonary artery pressures. The timing of peak right ventricular pressure differed, with the Doppler value consistently shorter (mean difference 16 ms, P < 0.05). Values of peak positive and negative right ventricular dP/dt and the time intervals Q-peak positive right ventricular dP/dt and pulmonary closure to the end of the pressure pulse differed between the two techniques in individual patients, but not in a consistent or predictable way. CONCLUSIONS--Doppler echocardiography significantly underestimates the peak right ventricular pressure and the time interval to peak right ventricular pressure in pulmonary hypertension, particularly when severe. These differences may be related to orifice geometry. Digitisation of Doppler records of tricuspid regurgitation provides useful semiquantitative estimates of absolute values and timing of peak positive and negative right ventricular dP/dt. Clinically significant differences may exist, however, and must be considered in individual patients.

OBJECTIVE--To evaluate the safety and efficacy of a prototype temporary stent (RX Flow Support Catheter, Advanced Cardiovascular Systems) in maintaining coronary perfusion and improving vessel patency in the event of acutely compromised flow complicating percutaneous transluminal coronary angioplasty. DESIGN--Prospective clinical study as part of a multicentre trial. SETTING--Regional cardiac centre catheterisation laboratory. PATIENTS--Eight patients undergoing routine percutaneous transluminal balloon coronary angioplasty in whom coronary artery dissection resulted in impaired coronary artery flow with angina or electrocardiographic ST segment shift, needing bail-out treatment at the time of the procedure. RESULTS--The RX Flow Support Catheter was successfully used and improved coronary flow in all cases, with a reduction in luminal stenosis and resolution of symptoms. The temporary stent was expanded for an average of 85 (range 30-209) minutes. In six patients it was used as a bridge to further treatment (permanent stent in four and coronary artery surgery in two) and two patients did not need further treatment. CONCLUSION--The temporary stent was safe and effective in the acute management of coronary dissection. The main advantages are its ease and speed of use, and successful restoration of coronary flow both to the distal artery and to affected side branches pending definitive treatment.

We have investigated the safety and efficacy of sealing the femoral arterial puncture site using purified bovine collagen in the catheter laboratory immediately after coronary stent implantation. Ten consecutive patients, mean age 64.6 years, pretreated with heparin, aspirin, and dextran underwent the insertion of a collagen plug immediately after coronary stent implantation. The mean activated clotting time was 512 seconds (range 320-999). Femoral arterial hemostasis was achieved before leaving the catheterization laboratory in nine of ten patients. Seven of these patients received additional mild groin compression with an air cushion compression device after hemostasis was successful. One of ten patients had persistent bleeding after delivery of the collagen plug and later required blood transfusion. The collagen plug may be a useful adjunct to obtaining hemostasis following coronary stent implantation, but further trials are required to test its reliability in fully anticoagulated patients.

Objectives: To explore patients9 understanding of chronic heart failure; to investigate their need for information and issues concerning communication. Design: Qualitative analysis of in-depth interviews by a constant comparative approach. Participants: 27 patients identified by cardiology and care of the elderly physicians as having symptomatic heart failure (New York Heart Association functional class of II, III, or IV) and who had been admitted to hospital with heart failure in the past 20 months. Results: Participants were aged 38–94 (mean 69 years); 20 had a New York Heart Association classification of III or IV. All had at least one concurrent illness. Participants sought information from the research interviewer about their heart failure, their prognosis, and likely manner of death. They also described several factors that could inhibit successful communication with their doctors. These included difficulties in getting to hospital appointments, confusion, short term memory loss, and the belief that doctors did not want to provide patients with too much knowledge. Conclusions: Good communication requires the ability both to listen and to impart relevant information. Effective and better ways of communicating with patients with chronic heart failure need to be tested. Disease specific barriers to effective communication, such as short term memory loss, confusion, and fatigue should be addressed. Strategies to help patients ask questions, including those related to prognosis, should be developed.

To characterise patients who appear to fulfil the diagnosis of heart failure with preserved systolic function clinically, echocardiographically, and by concentrations of brain-type natriuretic peptide (BNP).102 new cases of heart failure were identified over 24 months in 213 patients referred to a rapid access heart failure clinic. Patients with heart failure and preserved systolic function with contemporary markers of diastolic function were assessed to evaluate their cardiac status further.Forty patients (39%) had an ejection fraction (EF)45% and 62 (61%) had an EFor = 45%. Of these 62 patients, 30 (48%) fulfilled the case definition of diastolic heart failure. The remaining 32 (52%) had neither an EF45% nor abnormalities of diastolic function. Dobutamine stress echocardiography was performed on 26 (42%) patients with EFor = 45%, which provided an alternative explanation for symptoms in 15 (58%) patients. Concentrations of BNP were higher in patients with diastolic abnormalities (mean (SEM) 101.4 (32.5) pg/ml v 58.4 (6.78) pg/ml, p = 0.042) and with no diastolic abnormalities (199 (37.9) pg/ml v 58.4 (6.78) pg/ml, p0.0001) than in patients with no heart failure.Among ambulatory patients presenting with suspected heart failure in the community 19% have systolic dysfunction, 14% have diastolic dysfunction, and 15% seemingly have heart failure with neither systolic nor diastolic dysfunction. A new understanding, including alternative parameters of diastolic function, seems to be necessary to classify patients with heart failure and preserved systolic function.

Weight loss greater than 6% independently correlates with reduced survival in patients with congestive heart failure (CHF).1 Cardiac cachexia is a gradual and graded process, with wasting affecting muscle, bone, adipose tissue and the heart.1 Reduced appetite has been proposed as a important factor for weight loss caused by cardiac cachexia.2 The mechanism of cardiac cachexia remains largely unclear. Gastric myoneural inhibition and gastrointestinal hypomotility with delayed gastric emptying is commonly observed, and gut hormones may also play a role, because the anorexia is often characterised by a premature feeling of fullness and loss of hunger.2 The gut hormone ghrelin stimulates hunger, increases food consumption. and was previously shown to be raised in patients with cardiac cachexia and CHF.3 Ghrelin is produced from the stomach and usually rises in anticipation of a meal and then falls after the ingestion of nutrients. The gut hormone PYY3–36, acting as a terminator of hunger, is produced by the L cells in the distal gastrointestinal tract; it reduces appetite and 24 hour food intake by binding to the neuropeptide Y Y2 receptor in the hypothalamic arcuate nucleus.4 Severe pulmonary hypertension results in a low cardiac output and neurohumoral activation. Patients frequently report loss of appetite and weight, and since it occurs in a young population …

Aims New approaches in the treatment of ischaemic left ventricular dysfunction, including revascularization, make it increasingly important to identify heart failure cases resulting from coronary artery disease. Without angiography these cases may be missed. We investigated the frequency of coronary artery disease in incident cases of heart failure in the population. Methods and Results We identified all incident cases of heart failure in a population of 292000 in South London, U.K. by monitoring patients admitted to hospital and through a rapid access heart failure clinic. The presence and severity of coronary artery disease was identified by coronary angiography in patients under 75 years. Myocardial perfusion scanning was used to elucidate the aetiological significance of the coronary artery disease and identify hibernating myocardium. Three hundred and thirty-two cases of new heart failure were identified over 15 months. One hundred and thirty-six cases were under 75 years and angiography was undertaken in 99/136 (73%). Coronary artery disease was the aetiology in 71/136 (52%). In 18 of these 71 cases (25%), the aetiology was not recognised to be due to coronary artery disease prior to angiography, including eight cases with hibernating myocardium. Conclusion Coronary artery disease is the cause of 52% (95% CI 43–61%) of incident heart failure in the general population under 75 years. Clinical assessment without angiography under-estimates the proportion of patients with coronary artery disease, and fails to identify those patients who may benefit from revascularization.

Foreign bodies lodged in the bronchial tree are normally retrieved by bronchoscopy, but if this fails then thoracotomy is necessary. The case history is presented of a patient who had inhaled a dental post which could not be retrieved either by flexible or rigid bronchoscopy. Using biplane screening and intravascular retrieval devices introduced via an endotracheal tube, the dental post was removed successfully without the need for thoracotomy.

A National Pulmonary Hypertension Service has been set up in the UK, recognising the need for change in the way this complex and relatively rare condition is investigated and managed in response to therapeutic breakthroughs. In pulmonary hypertension (PH) resting mean pulmonary artery pressure exceeds 25 mm Hg at rest or 30 mm Hg during exercise. PH may complicate many different clinical disease processes or may develop as a primary phenomenon (PPH). Post mortem studies estimate the prevalence to be 1300 per million.1 The incidence of PPH in Europe and the USA is 1–2 cases per million population per year, rising to as high as 25–50 per million per year in patients using certain appetite suppressants.2 The mean age at diagnosis is 36 years with a female preponderance (1.7–3.5:1). There is no ethnic predisposition but familial PPH accounts for roughly 10% of cases.3 In patients with PPH both vasoconstriction and later thickening of the peripheral “resistance” vessel walls (remodelling) with associated thrombosis leads to raised pulmonary vascular resistance. Most of the structural changes that occur in these vessels are attributable to the proliferation of vascular smooth muscle cells. The mechanisms …

Although the frequency of haemoptysis in Eisenmenger's syndrome is well recognised, the high prevalence of pulmonary artery thrombus has been newly appreciated through the growing use of non-invasive imaging. Three patients with Eisenmenger's syndrome with haemoptysis are reported who underwent computed tomography pulmonary angiography and cardiovascular magnetic resonance. Each patient was found to have aneurysmal dilatation of the right pulmonary artery with large laminar thrombus. These cases illustrate a rising clinical problem in this special population-that is, how to treat and prevent large pulmonary artery thrombosis in the setting of haemoptysis. The authors discuss their approach to these cases and the known literature.

The nature of plasma cardiodilatin, the amino-terminal product of the human pro-atrial natriuretic peptide, was investigated by two separate radioimmunoassays directed against the N-terminal and the putative C-terminal of the cardiodilatin molecule: ANP-[Asn1-Lys16] and ANP-[Lys87-Arg98], respectively. Serial dilutions of normal and cardiac failure plasma exhibited parallelism with the synthetic peptide standard curves in both assays. The concentrations of N- and C-terminal cardiodilatin-immunoreactivity equivalents (-IE) were significantly higher in cardiac failure patients. N-terminal-IE: 912 +/- 87, normal subjects 129 +/- 13 (mean +/- SEM); C-terminal-IE: 7979 +/- 1784, normal subjects 895 +/- 213 (both p less than 0.001). Although the concentrations determined by the two assays were not identical, significant correlations were found between them in both normal subjects (r = .69, p less than 0.001) and cardiac failure patients (r = .72, p less than 0.01). Characterisation by gel permeation and fast protein liquid chromatography demonstrated coelution of the N- and C-terminal cardiodilatin immunoreactivities in a single chromatographic peak. These results suggest that the circulating cardiodilatin in normal subjects and patients with cardiac failure contains the entire prohormone amino-terminal sequence ANP-[Asn1-Arg98].

Variation in pulmonary artery pressure has important consequences for the interpretation of isolated pressure measurements in patients with chronic heart failure. To investigate the nature of diurnal variation in pulmonary artery pressure in chronic heart failure, eight angina-free men (aged 50-72 years) with treated chronic heart failure caused by ischaemic heart disease underwent continuous ambulatory pulmonary artery pressure recording by a transducer tipped catheter. The mean (1 SD) daytime pulmonary artery pressure was 29.6 (5.0) mm Hg systolic and 13.7 (5.6) mm Hg diastolic. The mean change in pressure from day to night was +5.1 (3.2) mm Hg systolic and +3.8 (1.7) mm Hg diastolic; and the mean change from standing to lying +9.3 (2.3) mm Hg systolic and +6.4 (2.1) mm Hg diastolic. In six of the eight patients there was considerable rise in pulmonary artery pressure at night, but in the two patients with the most severe symptoms there was no nocturnal rise. In patients with chronic heart failure, nocturnal pulmonary artery pressure is not determined by postural change alone. But interpretation of isolated pulmonary artery pressure measurements must take the posture of the patient into account.

Regional cerebral [11C]3- O-methyl-d-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 m M), and four were studied at hyperglycaemic plasma glucose levels (mean 13 m M). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 m M had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and d-glucose for the passive facilitated transport carrier system for hexoses across the blood–brain barrier (BBB). It is concluded that the number and affinity of d-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of d-glucose across the BBB.

A propos d'une observation: une malade de 73 ans est soumise a des hemofiltrations pendant 48 h pour la preparation a une intervention de chirurgie cardiaque. On observe une diminution etonnante de la natriurie. Les analyses de controle montrent que la teneur reelle en electrolytes des solutions utilisees pour l'hemofiltration ne correspond pas aux chiffres indiques par le fabricant (ces solutions ne sont pas des produits brevetes)