[Pulmonary hypertension in left heart disease: how to define it and how to manage it in 2013?]. / Hypertension pulmonaire associée aux maladies du coeur gauche: quelle définition et quelle prise en charge en 2013?

Pulmonary hypertension is a frequent complication of left heart disease arising from a wide range of cardiac disorders and is associated with poor prognosis. Its pathophysiology is complex with both passive mechanisms of elevated filling pressures in left cavities and occasionally reactive mechanisms of arterial vasoconstriction and remodelling to interplay. This stage, called <> pulmonary hypertension, further worsens the heart failure patients' prognosis but is still a matter of debate concerning the criteria to apply for its diagnosis and concerning the best way to manage it. This article gives an overview of the importance and pathophysiology of pulmonary hypertension associated with left heart disease, and discusses the challenges associated with its diagnosis and treatment.

Comparison of single and split-dose flubendazole treatment for the nematode parasite Trichostrongylus tenuis in experimentally infected grey partridges Perdix perdix.

Different therapeutic regimes using flubendazole for the treatment of Trichostrongylus tenuis infection in experimentally infected grey partridges Perdix perdix were examined. Flubendazole dosages of 4, 8 and 20 mg/kg were administered orally as a single dose or split into 3 or 9 parts given over 9 days. The efficacy against adult worms in the caeca improved with dose rate. Split doses were at least as effective as single doses, which removed up to 83% of adult T. tenuis. A dose of 20 mg/kg administered on a daily basis over 3 or 9 days gave the best clearance of T. tenuis, resulting in a reduction of at least 95% in worm burden.

Identifying governance strategies that effectively support ecosystem services, resource sustainability, and biodiversity.

Conservation scientists, national governments, and international conservation groups seek to devise, and implement, governance strategies that mitigate human impact on the environment. However, few studies to date have systematically investigated the performance of different systems of governance in achieving successful conservation outcomes. Here, we use a newly-developed analytic framework to conduct analyses of a suite of case studies, linking different governance strategies to standardized scores for delivering ecosystem services, achieving sustainable use of natural resources, and conserving biodiversity, at both local and international levels. Our results: (i) confirm the benefits of adaptive management; and (ii) reveal strong associations for the role of leadership. Our work provides a critical step toward implementing empirically justified governance strategies that are capable of improving the management of human-altered environments, with benefits for both biodiversity and people.

[Preoperative cardiac assessment before non-cardiac surgery: cardiac risk stratification]. / Evaluation cardiologique préopératoire avant chirurgie non cardiaque: stratification du risque cardiovasculaire.

Perioperative cardiac events occurring in patients undergoing non-cardiac surgery are a common cause of morbidity and mortality. Current guidelines recommend an individualized approach to preoperative cardiac risk stratification prior to non-cardiac surgery, integrating risk factors both for the patient (active cardiac conditions, clinical risk factors, functional capacity) and for the planned surgery. Preoperative cardiac investigations are currently limited to high-risk patients in whom they may contribute to modify the perioperative management. A multidisciplinary approach to such patients, integrating the general practitioner, is recommended in order to define an individualized peri-operative strategy.

[Pulmonary hypertension: difficult diagnosis and role of echocardiography]. / Hypertension pulmonaire: difficulté diagnostique et intérêt de l'échocardiographie.

Pulmonary hypertension (PH) is a complex disease leading, in its advance form, to a decreased quality of life and early mortality. In the early stage, non specific signs and symptoms are the rule. The diagnosis is often missed, leaving the patient alone to face the disease and its repercussion on his daily life. This article reviews the main PH causes and predisposing conditions. Signs and symptoms suggesting the diagnosis are reviewed as well as conditions recognised at high risk for the disease. The key role of echocardiography in establishing the diagnosis, assessing PH severity, cardiac repercussions and/or potential aetiologies, is addressed. Finally the importance of a multidisciplinary approach is recommended.

The effect of an experimental infection of the nematode Heterakis gallinarum on hand-reared grey partridges Perdix perdix.

We compared 26 hand-reared grey partridges given an experimental infection of the caecal nematode Heterakis gallinarum with 26 uninfected ones. Under laboratory conditions after 91 days, there were no measurable clinical effects of the infection. We found no effect of treatment on the amount of food eaten or on caecal dropping production. However, treated birds, in particular females, developed slightly lower body mass (around 2%) compared to the controls. At post-mortem examination, we found a positive relationship between breast muscle mass and the number of worms collected from the caeca of treated birds. Treated birds with no worms when examined had smaller breast muscle mass (4.6%) compared to the uninfected control birds. These results are largely different to those found in a similar study that documented significant negative impacts on most of these factors in 8 infected birds compared to 6 controls. Its findings were used in a published model to support a hypothesis that H. gallinarum maintained in the environment by common pheasants, the primary host for this worm, could negatively affect wild grey partridge productivity and survival. In the same model our data would not support this hypothesis. Possible explanations for the different results from the 2 experiments are discussed. Together they suggest that only in certain, as yet unidentified circumstances, could experimental H. gallinarum infections have deleterious effects on hand-reared grey partridges.

Infectious agents associated with respiratory disease in pheasants.

In a case-control study of the infectious agents associated with natural outbreaks of respiratory disease in pheasants, 28 batches of birds from sites affected by disease and eight batches of birds from unaffected sites were examined by six veterinary laboratories in England, Wales and Scotland, and tested for mycoplasmas, other bacteria and viruses. Sinusitis was the commonest sign of disease and was associated with Mycoplasma gallisepticum as detected by PCR in the trachea (P < 0.05) and conjunctiva (P < 0.01). Sinusitis was also associated with pasteurella cultured from the sinus (P < 0.05), antibody to avian pneumovirus (APV) (P < 0.01) and avian coronaviruses as detected by reverse-transcriptase PCR (P < 0.05); there was no association between disease and APV as detected by PCR. Avian coronaviruses were the most common infectious agents detected. They were genetically close to infectious bronchitis virus (IBV) but differed in their gene sequence from all the serotypes of IBV previously identified in domestic fowl, and serological tests with six known IBV types showed little cross reactivity. Mycoplasma species other than M gallisepticum were cultured in 18 batches of pheasants but, with the exception of Mycoplasma gallinaceum, were not associated with disease.

The estimation of density dependence using census data from several sites.

The discussion of density dependence in the ecological literature has tended to concentrate on significance testing, whereas estimation is often of more importance. In this paper we use simulation to investigate the bias and precision of a number of methods for estimating density dependence using census data from several sites. The estimation methods examined were a modification of an existing maximum likelihood approach, a regression method, and a new approach using restricted (or residual) maximum likelihood (REML). Simulations indicated that the REML method produced the most accurate estimates, with negligible bias for most parameter combinations. A further advantage of the REML method is that it can be easily implemented using standard statistical software. Using a second series of simulations we investigated the relationship between accuracy of estimation and sample size for the REML method. The results indicated that using more than one site gave substantial improvement in accuracy, but that using more than five sites gave little further improvement unless in excess of 10 years of data were available for each site. Where a standard error is required for the density dependence estimate we suggest using bootstrapping at the site level. Where this is not possible, a parametric bootstrap or a randomisation test may be used instead. The REML method is demonstrated using bag totals of red-legged partridges Alectoris rufa and grey partridges Perdix perdix for shoots on estates in East Anglia in the United Kingdom. This paper shows that combining information from several sites can give improved estimation of density dependence, particularly if REML estimation is adopted.

Complete Carbonylation of fac-

The rate constant of ligand exchange on the complex fac-[(99)Tc(H(2)O)(3)(CO)(3)](+) was determined by means of (13)C, (17)O, and (99)Tc NMR spectroscopy under pressurized conditions in aqueous media. After keeping the sample under CO pressure for an extended period, the formation of [(99)Tc(CO)(6)](+) could unambiguously be detected in the (13)C and (99)Tc NMR spectra.

Usefulness of the echocardiographic velocity ratio for detection of significant aortic stenosis.

In this study, which included 56 patients with aortic stenosis, the predictive value of the fractional shortening velocity ratio was evaluated. This Doppler index allowed detection of significant aortic stenosis (0.53 cm2/m2), with a positive predictive value of 93% and a negative predictive value of 92% for a cutoff value of 0.8.

Recurrent cardioembolic stroke related to late dislodgement of a right atrial pacing lead into the left atrium.

A 76-year-old woman had a permanent transvenous DDDR pacemaker implanted for complete atrioventricular block. She was hospitalized 4 years later for recurrent transient ischaemic attacks related to dislodgment of the atrial lead into the left atrium through a patent foramen ovale. The patient was successfuly treated by transvenous extraction of the atrial lead. The follow-up has been uneventful 12 months after the procedure. Left atrially dislodged pacemaker leads have to be retracted under full anticoagulation.

Clinical progress after randomized on/off pacemaker treatment for hypertrophic obstructive cardiomyopathy. Pacing in Cardiomyopathy (PIC) Study Group.

BACKGROUND: The therapeutic options for hypertrophic obstructive cardiomyopathy (HOCM) classically include medical treatment with beta-blockers and calcium antagonists or myectomy-myotomy as a surgical possibility for refractory cases. The observation that pacemaker activation of the heart in HOCM reduces the subaortic gradient is well known but less well investigated. METHODS: Eighty-three patients (33 female and 50 male) mean age 53 (18-82) years, with symptoms refractory to drug treatment and a resting gradient above 30 mmHg, who responded favourably to temporary pacing, were included in this prospective study and had a pacemaker (DDD) implanted. After an initial double-blind crossover phase of 6 months, patients were reinvestigated at 12 months and followed for a mean of 36 months. RESULTS: As observed during a screening investigation, the obstruction was significantly reduced from 72 +/- 35 mmHg to 29 +/- 24 mmHg (P < 0.01) when the pacemaker was on, while no major effect was seen during the sham phase. The effect was persistent at 1 year with a remaining resting gradient of 28 +/- 24 mmHg. In parallel, we documented an improvement in functional capacity, according to the NYHA classification and by quality of life analysis, and a significant improvement in dyspnoea and angina. Exercise on treadmill improved only in patients with reduced initial tolerance (< 8 min). During the mean follow-up of 36 months, 65 patients remained on pacing alone, with eight patients having additional AV-node ablation and five patients finally having surgery. CONCLUSION: This controlled multicentre study shows that pacemaker treatment is an option for HOCM patients; it is inoffensive and does not exclude alternative methods, but satisfies 79% of patients beyond 3 years.

An echocardiographic and magnetic resonance imaging comparative study of right ventricular volume determination.

Assessment of right ventricular volume and function is important in many clinical settings involving heart or lung disease. However, the complexity of the right ventricular anatomy has prevented accurate volume determination by two-dimensional echocardiography. In the present study, 5 models incorporating standard echocardiographic views, were used to determine right ventricular volume in 10 human subjects. Two models were contingent on the true crescentic appearance of the right ventricle, whereas the remaining 3 calculated the right ventricular volume as a pyramid, an ellipsoid or other tapering geometrical figures, respectively. Subsequently, echocardiographic right ventricular volumes were compared to magnetic resonance imaging derived volumes. Correlation analysis and agreement measurement between the echocardiographic and magnetic resonance end-diastolic volume were performed in 10 out of 10 subjects and in 9 out of 10 subjects for the end-systolic volume. The 2 crescentic models resulted in the most reliable estimation of right ventricular volume. Those findings suggest that models based on right ventricular anatomical landmarks are feasible and should be preferred in echocardiographic studies.

Acute hemodynamic effects of atrioventricular pacing at differing sites in the right ventricle individually and simultaneously.

We hypothesized that pacing, which provided a rapid uniform contraction of the ventricles with a narrower QRS, would produce a better stroke volume and cardiac output (CO). We sought to study whether pacing simultaneously at two sites in the right ventricle (right ventricular apex and outflow tract) would provide a narrower QRS and improved CO in 11 patients undergoing elective electrophysiology studies. Patients were studied by transthoracic echocardiography measurement of CO using the Doppler flow velocity method in normal sinus rhythm, AOO pacing (rate 80), DOO pacing in the right ventricular apex (AV delay 100 ms), DOO pacing in the right ventricular outflow tract, and DOO pacing at both right ventricular sites simultaneously in random order. The COs were 5.42 +/- 1.83, 5.61 +/- 1.97, 5.67 +/- 1.6, 5.84 +/- 1.68, and 5.86 +/- 1.52 L/min, respectively (no significant difference by repeated measures analysis of variance [ANOVA]). The QRS durations were 0.09 +/- 0.02, 0.09 +/- 0.02, 0.13 +/- 0.027, 0.13 +/- 0.03, and 0.11 +/- 0.03 secs respectively. Repeated measures ANOVA showed that the QRS duration significantly increased with right ventricular apex or right ventricular outflow tract pacing compared to sinus rhythm and AOO pacing (P < 0.001) but then diminished with pacing at both sites (P < 0.01). QRS duration was not correlated with CO, however the change in QRS duration correlated significantly with the change in CO when pacing was performed at the two right ventricular sites simultaneously. In conclusion, during DOO pacing, there was a trend for pacing in the right ventricular outflow tract or both sites to improve the CO compared to the right ventricular apex. With simultaneous pacing at both ventricular sites, the QRS narrowed. Further studies will be required to see if this approach has value in patients with poor left ventricular function or congestive heart failure.

Dual chamber pacing in hypertrophic obstructive cardiomyopathy: beneficial effect of atrioventricular junction ablation for optimal left ventricular capture and filling.

Clinical improvement with dual chamber pacing has largely been reported in patients suffering from hypertrophic obstructive cardiomyopathy and mainly attributed to the reduction of the subaortic pressure gradient. To be effective, pacing must induce a permanent and complete capture of the LV. In two patients of our collective, symptoms (angina and dyspnea NYHA Class III and/or syncopes) persisted or relapsed despite pacing. This was related to the inability to obtain full LV capture due to a too-short native PR interval. RF ablation of the AV junction was therefore performed in both patients, resulting in permanent AV block in one and prolonged PR interval up 310 ms in the second. Pacing was thereafter associated with an immediate and significant clinical improvement related to permanent LV capture, whatever the patient's activity. After RF ablation, the AV delay was set up to induce the best LV filling, as assessed by Doppler analysis of mitral flow. Our observations suggest that RF ablation or modification of the AV junction can be a successful procedure in some patients with residual or recurrent symptoms, when the latter result from a loss of capture or from the inability to program an AV delay that does not compromise the active component to LV filling. Doppler echocardiography is a simple and effective mean to assess the hemodynamic effect of AV interval modulation in this setting.

Prognosis after stroke followed by surgical closure of patent foramen ovale: a prospective follow-up study with brain MRI and simultaneous transesophageal and transcranial Doppler ultrasound.

BACKGROUND: The risk of stroke and the long-term prognosis of recurrent strokes in young patients with patent foramen ovale (PFO) are not well known. For this reason, the treatment of these patients remains empirical. An alternative treatment to prolonged antithrombotic therapy may be surgical closure of the PFO. METHODS: Thirty patients (20 men and 10 women) with stroke and PFO were prospectively selected among 138 patients with stroke and PFO for a study of surgical closure of PFO at our center. Eligible patients were < 60 years old, had negative results of a systematic search for another cause of stroke (first criterion), and met two of the four following criteria: (1) recurrent clinical cerebrovascular events or multiple ischemic lesions on brain MR, (2) PFO associated with an atrial septal aneurysm, (3) > 50 microbubbles counted in the left atrium on contrast transesophageal echocardiography (TEE), and (4) Valsalva maneuver or cough preceding the stroke. Patients selected in this manner for surgery were considered to be a subgroup with a higher risk of stroke recurrence. RESULTS: All patients had a direct suture of PFO while under cardiopulmonary bypass without recorded early or delayed significant complication. All patients underwent a new brain MRI and TEE simultaneous with transcranial Doppler ultrasonography after contrast injection at 8 +/- 3 months after surgery. After a mean follow-up of 2 years without antithrombotic treatment, no recurrent cerebrovascular event (stroke or transient ischemic attack [TIA]) and no new lesion on MRI had developed. Postoperative contrast TEE and transcranial Doppler ultrasonography showed that two patients had residual interatrial right-to-left shunting, although much smaller than before surgery, associated with single versus double continuous suture. CONCLUSIONS: Our study of 30 selected stroke patients with surgical suture of PFO showed a stroke recurrence rate of 0% and no significant complication. Residual right-to-left shunting may be avoided by double continuous suture of the PFO. In the absence of controlled studies to guide individual therapeutic decisions, our findings show that PFO closure can be done safely and may be considered to avoid recurrence in selected patients with long life expectancy and presumed paradoxic embolism.

Doppler echocardiographic assessment of the new ATS medical prosthetic valve in the aortic position.

Advancing The Standard (ATS) Medical (ATS Medical Inc., Minneapolis, MN) is a new mechanical bileaflet valve, composed of pyrolitic carbon. The aim of this study was to define in a blinded manner the Doppler echocardiographic characteristics of normally functioning ATS Medical prostheses with respect to their size. Forty consecutive patients (29 men, mean age 58 +/- 13 years), clinically stable, and without evidence of valve dysfunction, were studied from 1993 to 1995. Doppler echocardiography was performed at least 3 months after valve replacement with ATS Medical valves (5 n degrees 21, 8 n degrees 23, 12 n degrees 25, 10 n degrees 27, 5 n degrees 29). Maximum and mean transprosthetic pressure gradients were calculated by the simplified Bernoulli equation. Functional valve surface area was assessed by the continuity equation using the external diameter of the prostheses to calculate the subaortic surface area. The Doppler velocity index was obtained by the ratio of subaortic and transaortic velocities and the performance index was calculated dividing the effective orifice area by the actual orifice area. For the most commonly used aortic valve (25 mm), the maximum pressure gradient was 17 +/- 8 mmHg, the mean gradient 11 +/- 4 mmHg, the functional surface area 2.2 +/- 0.4 cm2, the Doppler velocity index 0.44 +/- 0.07, and the performance index 0.68 +/- 0.11. This study provides the normal range for Doppler hemodynamic characteristics of the various sizes of the ATS valve.

Stroke recurrence in patients with patent foramen ovale: the Lausanne Study. Lausanne Stroke with Paradoxal Embolism Study Group.

Patent foramen ovale (PFO) is more common in patients with stroke than in matched controls, but the stroke mechanism and late prognosis are not well known. We studied features, coexisting causes, and recurrences of stroke in 140 consecutive patients (mean age 44 +/- 14 years) with stroke and PFO admitted to a population-based primary-care center. We selected the patients from 340 patients (41%) aged < or = 60 years with acute stroke. The initial event was brain infarction in 118 patients (84%) and TIA in 22 (16%). Intracranial embolic occlusions were present on angiography or transcranial Doppler in most patients admitted within 12 hours of onset, whereas a venous source was clinically apparent in only six patients (5.5%). Pulmonary embolism, Valsalva maneuver at onset, and coagulation abnormalities were rare, but one-fourth of the patients had an interatrial septum aneurysm (ISA) that coexisted with PFO. An alternative cause of stroke was present in only 22 patients (16%), usually cardiac (atrial fibrillation, severe mitral valve prolapse, akinetic left ventricular segment). During a mean follow-up of 3 years, the stroke or death rate was 2.4% per year, but only eight patients had a recurrent infarct (1.9% per year). This low rate of recurrence contrasted with the severity of initial stroke, which left disabling sequelae in one-half the patients. Multivariate analysis showed that interatrial communication, a history of recent migraine, posterior cerebral artery territory infarct, and a coexisting cause of stroke were associated with recurrence, whereas ISA and treatment type (coagulant or antiaggregant therapy, surgical closure of PFO) were not. However, given the low number of events, these findings must be taken with caution. In conclusion, our study shows that stroke associated with PFO with or without ISA is not commonly due to a coexisting cause of stroke. It is usually embolic, although a definite source cannot often be demonstrated. The presenting stroke is often severe, but recurrence is uncommon. The demonstration of factors associated with a higher risk of recurrence in subgroups of patients is critical for the long-term management of these patients.