[Prevention of venous thromboembolism following cardiac, vascular or thoracic surgery]. / Prévention de la maladie thromboembolique veineuse périopératoire en chirurgie cardiaque, vasculaire et thoracique.

In the absence of thromboprophylaxis, coronary artery bypass graft surgery (CABG), intrathoracic surgery (thoracotomy or video-assisted thoracoscopy), abdominal aortic surgery and infrainguinal vascular surgery are high-risk surgeries for the development of venous thromboembolic events (VTE). The incidence of VTE following surgery of the intrathoracic aorta, carotid endarterectomy or mediastinoscopy is unknown. Data from the litterature are lacking to draw evidence-based recommandations for venous thromboprophylaxis after these three types of surgeries, and the following guidelines are but experts'opinions (Grade D recommendations). Thromboprophylaxis is recommended after CABG (Grade D), with either subcutaneous (SC) low molecular weight heparin (LMWH) or SC or intravenous (i.v.) unfractioned heparin (UH) (PTT target = 1.1-1.5 time control value) (both grade D). This may be combined with the use of intermittent pneumatic compression device (Grade B). After valve surgery. The anticoagulation recommended to prevent valve thrombosis is sufficient in order to prevent VTE. We recommend thromboprophylaxis with either LMWH or low dose UH to prevent VTE after aortic or lower limbs infrainguinal vascular surgery (both grade B and D). Vitamine K antagonists (VKA) are not recommended in this indication (Grade D). We recommend thromprophylaxis following intrathoracic surgery via thoracotomy or videoassisted thoracoscopy (grade C). Either subcutaneous LMWH or subcutaneous or i.v. low dose UH may be used (Grade C). Efficacy of intermittent pneumatic compression device has been demonstrated in a study (grade C). VKA are not recommended (grade D). No further recommendation regarding the duration of thromboprophylaxis after these three types of surgeries can be made.

[Coronary stent evaluation with cardiac CT: Literature review]. / Évaluation des stents coronaires en scanner cardiaque: revue de la littérature.

Since the introduction of the 64-generation scanners, the accuracy and robustness of the diagnosis of coronary artery disease has progressed. The main advantage of cardiac CT is the exclusion of coronary artery disease by its excellent negative predictive value. Currently, cardiac CT applications extend thanks to innovations both in terms of technological development systems scanner or stents implanted. This is a literature review of stent evaluation with cardiac CT.

Role of tricuspid regurgitation and left ventricular damage in the treatment of right ventricular infarction-induced low cardiac output syndrome.

To evaluate, in right ventricular (RV) myocardial infarction, the role of tricuspid regurgitation (TR) and left ventricular (LV) damage and the response to treatment of low cardiac output, 20 patients were prospectively studied. Volume infusion increased cardiac output only slightly (11%, p less than 0.001), despite a dramatic increase in ventricular filling pressures. Dobutamine (4 micrograms.kg-1.min-1) markedly increased cardiac output (24%, p less than 0.001) with a decrease in ventricular filling pressures. In the 5 patients with TR, dobutamine only modestly increased cardiac output (9 vs 26%, p less than 0.001), while stroke index and LV end-diastolic dimensions decreased in comparison (-5 vs 33% and -6 vs 9%, respectively, p less than 0.001). In the absence of TR (n = 15), there was no significant difference in response to volume expansion between patients with normal (n = 7) and depressed LV ejection fraction (n = 8). In contrast, dobutamine, in patients with depressed LV function, induced a greater increase in cardiac output (38 vs 17%, p less than 0.01) and RV ejection fraction (36 vs 12%, p less than 0.05). All patients with RV infarction-induced low cardiac output responded only modestly to volume loading. Dobutamine is particularly efficacious in patients without TR who have depressed LV function by improving RV function and, consequently, LV preload. In the 5 patients with TR, increasing RV contractility failed to improve the forward stroke volume by increasing the regurgitant fraction.

Enoximone vs nicardipine during the early postoperative course of patients undergoing cardiac surgery. A prospective study of two therapeutic strategies.

The hemodynamic effects of enoximone and nicardipine were compared during the early postcardiac surgery period in 40 patients with systemic hypertension and moderate cardiac dysfunction. Patients were prospectively randomized into two groups. Mean right atrial pressure was maintained above 7 mm Hg. The drug infusion rate was adjusted to maintain mean systemic artery pressure (SAP) within the 65 to 80 mm Hg range. Complete hemodynamic evaluations were performed before any drug infusion and during the following 24 h with special attention to O2-related variables. Oxygen consumption, cardiac index, and stroke index improved significantly and similarly in the two groups. The SAP and systemic vascular resistance decreased more rapidly in the enoximone group but whole body lactate level increased after the second hour of infusion. Furthermore, this was paralleled by an arteriovenous O2 contents difference deficit. In our study, nicardipine was found superior over enoximone in terms of recovery from intraoperative tissue hypoxia. Furthermore, enoximone's inotropic effects were not found to be clinically relevant.

Elastic energy as an index of right ventricular filling.

BACKGROUND: Right ventricle (RV) preload assessment remains controversial because the complexity of RV geometry is an obstacle to wall stress modeling. We developed a method to evaluate end-diastolic RV elastic energy (EL), a variable that integrates all the stretching effects of venous return and that can be easily estimated at the bedside from the area under the diastolic RV pressure-volume curve. The purpose of this study was to compare the clinical utility of EL and of the two conventional variables used to assess RV filling, ie, right atrial pressure (Pra) and RV end-diastolic volume (EDV). METHOD: We studied 26 postoperative patients who required a rapid fluid challenge. Energetics were evaluated by constructing the RV pressure-volume loop at the bedside using right heart catheterization with RV ejection fraction (EF) derivation. Correlations between RV filling and RV performance (ejection and mechanical efficiency) were studied. RV filling indexes were Pra, EDV, and EL. Indexes of RV ejection were stroke volume (SV), RV stroke work (RVSW), mechanical energy expenditure during ejection (EM), and total energy expenditure of contraction (ET). Indexes of RV mechanical efficiency were EF and the EM/ET ratio. RESULTS: Three important results were obtained. First, among RV ejection indexes, those that correlated best with RV filling indexes were EM and ET. Second, we found significant linear relationships between improved RV filling, as assessed by changes in EDV and EL, and improved RV ejection, as assessed by changes in SV, RVSW, EM, or ET. Third, changes in EDV and EL also predicted improved mechanical efficiency, as assessed by changes in EF and EM/ET. In, all situations, changes in EL yielded the strongest correlations. CONCLUSIONS: Derivation of EL is simple and appears to be the best clinical means of assessing Starling's law of the heart for the RV.

Decreased paradoxic pulse from increased venous return in severe asthma.

During severe asthma, paradoxic pulse may result from increased impedance to left ventricular ejection, mechanical impairment of left ventricular filling by ventricular interdependence or decreased pulmonary venous return augmented by hypovolemia. We studied the effect of reversible blood volume expansion by MAST inflation during severe attacks of asthma. Ten patients with clinically detectable paradoxic pulse of more than 20 mm Hg were studied. All had a history of reversible bronchial asthma with evidence of respiratory and circulatory failure. Standard therapy for asthma was started. We observed no difference in respiratory and heart rates during MAST inflation. Paradoxic pulse was consistently decreased during MAST inflation; paradoxic pulse returned to baseline values after MAST deflation. The decrease in paradoxic pulse was produced by an increased inspiratory systolic arterial pressure. We conclude that a reduction in pulmonary venous return is more important than ventricular interdependence in producing paradoxic pulse during severe asthma.

Hemodynamic profile in severe ARDS: results of the European Collaborative ARDS Study.

OBJECTIVE: Although the acute respiratory distress syndrome (ARDS) was identified as long as 30 years ago, potential therapeutic objectives have been defined from small series rather than large trials. Moreover, relationships between ARDS and hemodynamics are unclear. The European Collaborative ARDS Study was designed to identify factors influencing the pathogenesis, severity, and prognosis of ARDS. Analysis of the hemodynamic profiles collected during this study and of their contribution to the above-mentioned facets of ARDS is the focus of the present report. DESIGN: Prospective clinical study. SETTING: 38 European intensive care units (ICUs). PATIENTS AND METHODS: We collected 2758 sets of data from 586 patients, including baseline data, data on proven or suspected causes of ARDS differentiating direct and nondirect lung injury, and data on baseline status including multiple organ dysfunction (MOD) with differentiation of primary ARDS from ARDS secondary to severe systemic disorders. Events during follow-up were also recorded, including whether the acute respiratory failure did or did not improve after 24 h (groups A and B, respectively). When available, hemodynamic data were recorded at enrollment (day 0), on days 1-3, 7, 14, and 21, and at discharge or at the time of death in the ICU. RESULTS: Although the rate of pre-existing disease and the nature and rate of complications varied widely among etiologic categories, differences in the hemodynamic profile occurred only between primary and secondary ARDS. Both at inclusion and during the course of the illness, variables that were used to investigate Va/Q mismatch [arterial oxygen tension (PaO2, arterial oxygen saturation, right-to-left shunt, and the PaO2/fractional inspired oxygen (FIO2) ratio] predicted survival. High pulmonary artery pressure (PAP) and low systemic artery pressure (SAP) were also related to the prognosis. In the logistic regression model including hemodynamic and oxygen-related variables, however, the only independent predictors of survival were the ratio of right over left ventricular stroke work (RVSW/LVSW) and the PaO2/FIO2 ratio at admission. On day 2, the best prognostic model included: age [odds ratio (OR) = 1.04, p = 0.0004], opportunistic pneumonia as the cause of ARDS (OR = 3.2, p = 0.03), existence of MOD (OR = 1.9, p = 0.03), PaO2/FIO2 (OR = 0.96, p = 0.005), and RVSW/LVSW (OR = 25, p = 0.02). A high RVSW/LVSW ratio, high systolic PAP, low diastolic SAP, and low PaO2/FIO2, and increased right atrial pressure were negative prognostic indicators during follow-up. CONCLUSION: In addition to the cause of ARDS and the early time-course of lung function, a high systolic PAP and a low diastolic SAP were strong independent indicators of survival.

Value of elementary, combined, and modeled hemodynamic variables.

PURPOSE: It has been well recognized that the usefulness of the clinical examination and simple hemodynamic variables in the critically ill is limited. Modelization for hemodynamic analysis may improve the diagnostic performance by a systematic and multivariate analysis. This requires a rigorous formalization that may otherwise expand the usefulness of hemodynamic data, both as predictors and as therapeutic targets. Our study was designed to test the value of a model for assessing the pathophysiology of circulatory disorders and for establishing the diagnosis. METHODS: We tested all available variables using survival as the end point. A population of 223 patients (652 measurements) with compromised circulatory status was studied. We evaluated traditional variables: (1) morphological and physical data, (2) elementary right heart catheterization data, and (3) usually calculated variables, versus (4) new modeled variables. These new modeled variables were derived from a previously validated computer program for hemodynamic evaluation. They expressed differences between observed hemodynamic performance and estimated needs. RESULTS: Among traditional variables, major prognostic factors were: (1) in all patients, lactate level elevation, physical signs of hypoperfusion, and a decreased systemic arterial pressure; (2) in septic patients, a high PaO2/SaO2 ratio; (3) in nonseptic patients, low left ventricle work indices. In all cases, modeled hemodynamic variables assessing performance-needs adequacy enhanced the prognostic value of hemodynamic monitoring. CONCLUSIONS: Compared with traditional variables, modeled variables were found of greater interest to quantify pathophysiology of shock. These results enabled us to validate the initial step of the hemodynamic reasonning formalization and to develop "new" diagnostic criteria that more closely fit the interrelationship between pathophysiology, diagnosis, and prognosis.

[Early postoperative thrombolysis of Saint-Jude aortic valve prosthesis]. / Thrombolyse postopératoire précoce d'une valve de Saint-Jude aortique.

The authors report a case of thrombolytic therapy with streptokinase in the early postoperative period after aortic valve replacement with a Saint Jude medical prosthesis. After good initial progress, the patient had to be reoperated on the 12th postoperative day for sternal disunion. Reoperation was followed rapidly by progressive thrombosis of the aortic prosthesis demonstrated by repeated Doppler echocardiographic examination. The impossibility of eliminating mediastinitis led to medical thrombolysis. The outcome was favourable after a regressive cerebral embolic event. This case illustrates the value of Doppler echocardiographic examination in the postoperative period. Thrombolysis may constitute an alternative to reoperation when the operative risk is high. The risk of thrombolysis may not be as great as some believe.

[Aortic insufficiency in certain so-called systemic diseases]. / Insuffisance aortique au cours de certaines maladies dites systémiques.

The authors present a retrospective study of all the patient followed up for systemic disease in the rheumatology Department of Bichat hospital between 1975 and 1984 in whom aortic regurgitation developed. Only rare or previously undescribed associations were retained: two MacDuffie syndromes, one adult form of Still's disease, one Takayashu's disease, one association of rheumatoid arthritis and Takayashu's disease, one rheumatoid arthritis, one Cogan's syndrome and two cases of disseminated lupus erythematosis. The authors use these cases and a review of the literature to discuss the possible physiopathological mechanisms of the aortic regurgitation. This study confirms the value of regular clinical cardiovascular examination with echocardiography in cases with progressive symptoms. The evolution of the vascular disease seems to be more or less parallel to that of the systemic disease and in a significant number of cases it becomes sufficiently severe to become the main clinical problem. In our series, there was one sudden death, one death due to cardiogenic pulmonary oedema and three patients required aortic valve replacement.

[Postpartum myocardial infarction with normal coronary arteries. Apropos of a case]. / Infarctus du post-partum à coronaires saines. A propos d'un cas.

A case of painless anteroseptal and high lateral wall infarction presenting as cardiogenic shock with pulmonary oedema 24 hours after childbirth complicated by severe post partum haemorrhage with a coagulation defect, is reported. Coronary angiography performed one month later was normal, with a negative ergometrine provocation test. The authors review five previous reports in the medical literature, and discuss the possible physiopathological mechanisms which, alone or in association could have operated in the reported case.

[Angiotensin-converting enzyme and diabetes mellitus]. / Enzyme de conversion de l'angiotensine et diabète sucré.

Elevation of serum angiotensin-converting enzyme (ACE) has been reported to occur in 25 p. 100 of diabetic patients. This finding would decrease the specificity of increased ACE level in sarcoidosis. We measured serum ACE in 90 diabetic patients with simultaneous analysis of various parameters including those appreciating the degree of metabolic control. Serum ACE values, observed in diabetics are not different from values measured in controls, respectively 22,3 +/- 6,4 and 21,1 +/- 6,7 U/ml (means +/- SD). Only 5,5 p. 100 of diabetic patients had (slightly) increased serum ACE levels, i.e.: levels above mean +/- 2 SD of values observed in controls. Serum ACE levels were higher in insulin-dependent diabetics: 24,7 +/- 6,7 (n = 34) than in non insulin-dependent diabetics: 20,8 +/- 5,9 (n = 56) (p = 0,01). In the diabetic group, there is a positive linear correlation between serum ACE level and 24h-glycosuria or glycosylated A1c hemoglobin. These are parameters appreciating middle or long-term metabolic control. In the other hand, no correlation was observed between serum ACE and glycemia, triglyceridemia, serum creatinin, blood pressure or the presence of diabetic retinopathy. These findings do not show an elevation of serum ACE in diabetic patients. However, they suggest that long-term metabolic control of diabetes influence serum ACE level.

[Anxiety and depressive disorders in cardiovascular diseases]. / Troubles anxieux et depressifs dans les pathologies cardiovasculaires.

Cardiovascular diseases are often associated with anxiety and depression. The literature gives different interpretations of this comorbidity. Psychopathological factors have been successively studied as risk factors, comorbid disorders and factors influencing the prognostic. The authors describe the incidence and the prevalence of anxiety and depression, first in coronary heart disease and secondly before cardiac surgery. The prognostic significance of these psychological factors is also reviewed. Physiopathological hypothesis and practical application in clinical practice are proposed.

[Hemodynamic and coronary effects of molsidomine in patients with stable coronary insufficiency in the basal state, during an atrial stimulation test and a cold test]. / Effets hémodynamiques et coronaires de la molsidomine chez des insuffisants coronaires stables à l'état basal, lors d'une épreuve de stimulation auriculaire et lors d'un test au froid.

The heart rate (HR), the cardiac output (Qc) and the coronary sinus flow rate (Qcs), the left ventricular systolic and end-diastolic pressures (LVSP, LVEDP), the femoral artery pressure (FAP) and the difference between the coronary arterial and coronary venous oxygen tension (DAVcO2) were measured in patients with stable coronary insufficiency without cardiac failure, before and 40 to 60 minutes after 2 or 3 mg of molsidomine (M). In 20 patients, these measurements were made in the basal state, in spontaneous rhythm (SP). In 8 of these patient, (including 3 receiving beta-blockers) the measurements were made during an atrial stimulation test (ST) and in 8 other patients, all receiving long-term beta-blocker therapy, the measurements were made during a cold test (CT). At the basal state in SR, a gradual reduction in the LVSP to 70% or less of its initial value was observed in the patients receiving 3 mg of M (2 of whom received beta-blocker treatment). The LVSP was immediately restored by vascular filling. In 16 patients, M decreased the LVSP, the LVEDP, the FAP, the Qc and the double product (DP = LVSP X HR). The DAVcO2 was unchanged. Qcs and MVO2 (MVO2 = Qcs X DAVcO2) were decreased. In the course of ST, the haemodynamic and coronary changes are similar to those seen in the basal state. During the Ct, the increase in the LVSP, FAP and DP was significantly reduced by M. The variations in Qcs and coronary resistance (FAP/Qcs) were also significantly different after M., with better metabolic regulation of the coronary circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hypophosphoremia during mechanical ventilation for chronic obstructive bronchopathies]. / Hypophosphorémie au cours de la ventilation mécanique des bronchopathies chroniques obstructives.

Hypophosphoremia may interfere with respiratory function in chronic obstructive pulmonary diseases (COPD) through different mechanisms: muscular exhaustion and weakness. Accordingly, the frequency and magnitude of hypophosphoremia was studied in 36 consecutive patients with acute respiratory failure and mechanical ventilation. Initial phosphoremia was normal (1,32 +/- 0,12 mmol/l) but often and rapidly decreased in all patients after mechanical ventilation had been started (0,54 +/- 0,14 mmol/l after 24 h). After this, phosphoremia remained low, slowly increasing with continued enteral nutrition (2000 Kcal, 276 g of glucides, 33 mmol/l of phosphorus). Four patients had severe hypophosphoremia after 24 h of mechanical ventilation (less than 0,30 mmol/l). Phosphoremia returned to a normal level 36 h after extubation. Hypophosphoremia was closely linked to pH improvement (r = + 0,67, P less than 0,001) and was paralleled by a drop in phosphaturia, suggesting intra-cellular penetration of phosphorus.

Hemodynamic exercise testing and hormonal status in a sheep model of congestive heart failure.

BACKGROUNDS: The aim of the present study was to investigate the hormonal status and hemodynamic performance of a sheep model of congestive heart failure at rest and during maximum exercise. METHODS: The current investigation was a prospective, experimental study and was carried out in an experimental laboratory. Animals were randomly assigned to a congestive heart failure or control group. In the congestive heart failure group, sequential intracoronary embolization with 90-micron polystyrene microspheres was performed until the left ventricle ejection fraction fell below 35%. All animals were chronically instrumented to continuously monitor the pulmonary artery flow, right ventricle pressure, and left ventricle pressure. Blood samples were collected for hormone assays (atrial natriuretic factor, endothelin, renin plasmatic activity, noradrenaline, and adrenaline), and hemodynamic variables, including expired gases, were measured at baseline and during exercise. RESULTS: Six animals in each group were studied. Compared to the controls, all of the studied plasma hormones were elevated in the model, and the most discriminative measurement was the atrial natriuretic factor (175±57 vs. 52±5 pg/mL, P<0.01). Exercise performance decreased by 30% to 40% in congestive heart failure animals compared to that of the controls (peak exercise VO2, 30±7 vs. 51±5 mL/min, P<0.01; anaerobic threshold, 21±7 vs. 37±2 mL/min, P<0.01; cardiac output, 201±33 vs. 350±45 mL/min.kg, P<0.01. CONCLUSION: Intracoronary embolization in sheep produces a stable and reproducible model that acceptably simulates congestive heart failure in humans. This model is suitable for the long-term assessment of therapeutic strategies and was designed to improve exercise capabilities.