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Biomedical subjects

R Isnard

Publications and source records attributed to R Isnard.

At least 19 recordsLinked to original sources
PubMed2006

Low negative predictive value of dobutamine stress echocardiography before abdominal aortic surgery.

BACKGROUND: According to previous studies, a negative dobutamine stress echocardiography (DSE) test before major vascular surgery indicates that postoperative myocardial necrosis is very unlikely. We believe that the use of new cardiac troponin assays which can detect small amounts of myocardial necrosis results in a lower DSE negative predictive value for myocardial necrosis. METHODS: A total of 418 consecutive patients were screened using the ACC/AHA Guideline for Perioperative Cardiovascular Evaluation for Noncardiac Surgery before scheduled abdominal aortic surgery. Of these 143 met ACC/AHA criteria for non-invasive testing and underwent DSE. Patients with a negative DSE were deemed to be fit for surgery. A positive DSE led to a coronary angiogram. DSE was negative in 110 (77%) and positive in 33 (23%) patients. Myocardial necrosis was monitored up to the third postoperative day by daily cardiac troponin I (cTnI) measurement and a daily 12-lead ECG. RESULTS: Coronary angiography showed artery stenosis in 27 (84%) of 32 patients with a positive DSE. The negative predictive value of DSE for cTnI elevation was 92.7% (95% CI 86.2-96.8%). This was significantly lower than the lowest value of negative predictive value for myocardial necrosis assessed in previous studies. CONCLUSION: A negative DSE prescribed before scheduled aortic surgery according to ACC/AHA guidelines does not rule out postoperative myocardial necrosis.

Adult↗
PubMed2006

[Preoperative cardiac assessment using dobutamine stress echocardiography].

Postoperative myocardial ischaemia is the leading cause of life expectancy impairment after high cardiac risk surgical procedures. Preoperative identification of patients at high risk for such complication helps reducing its postoperative incidence through therapeutic adjustments. The former relies upon preoperative selection of patients who are candidates for cardiac testing using dobutamine stress echocardiography, according to ACC/AHA guidelines. This exam evaluates echographic myocardial response to a pharmacological stress induced by dobutamine infusion. Its aim is to reproduce part of the stress the myocardium will undergo during surgical procedure. A stress induced myocardial ischaemia suggests such a complication could occur postoperatively. A positive dobutamine stress echocardiography justifies to prescribe preoperative anti-ischaemic treatment in order to reduce the cardiac risk of the further surgical procedure. Moreover, it justifies clear definition of perioperative haemodynamic objectives. Whatever the result of the dobutamine stress echocardiography, cardiac ischaemia should be monitored up to the third postoperative day on the basis of a daily 12-lead electrocardiogram recording and daily plasmatic troponin Ic measurement.

Adult↗
PubMed2006

[Treatment of obstructive aortic atheroma in homozygotic familial hypercholesterolemia].

The object of this report is to describe the surgical treatment of a rare clinical form of homozygotic familial hypercholesterolaemia (HFH) associating valvular and supravalvular stenosis with coronary ostial stenosis. Three patients, two male and one female, aged 15, 23 and 41 respectively, suffering from HFH diagnosed in early childhood, presented with obstacles to left ventricular ejection and myocardial ischaemia due to coronary ostial stenosis. Surgery consisted of corrections in a single procedure of all abnormalities by aortic valve replacement, ascending aortic replacement and widening of the coronary artery ostia which were reimplanted on the aortic tube. The postoperative course of all three patients was favourable. Postoperative echocardiography showed the normal position of the valvular prosthesis, normalisation of the left ventricular ejection fraction with no significant residual obstruction. Angioscan of the coronary arteries showed a good result of coronary ostial widening. The authors conclude that HFH is a rare condition and that disease of the ascending aorta is common in this variety with involvement of the aortic valve, the ascending aorta and the coronary ostia. The surgical procedure described by the authors allows correction of all the abnormalities with the hope of a good long-term result.

Adolescent↗
PubMed2003

Accuracy of European diagnostic criteria for familial hypertrophic cardiomyopathy in a genotyped population.

BACKGROUND: Since the sensitivity of conventional diagnostic criteria for familial hypertrophic cardiomyopathy (HCM) is low, new diagnostic criteria were proposed by a European collaboration. However, their diagnostic value remains unknown. The aim of the study was to evaluate the accuracy of these new criteria, using the genetic status as the criterion of reference. METHODS: We studied 109 genotyped adults (54 genetically affected, 55 unaffected) from 7 families (mutations in 3 genes). Major European echographic criteria were a maximal wall thickness >or=13 mm or >or=15 mm according to the segment involved, or the presence of SAM. Major European ECG criteria were abnormal Q waves, left ventricular hypertrophy, or marked ST-T changes. Combined major/minor European criteria were also evaluated. RESULTS: Sensitivity and specificity of major European criteria (72 and 92%, respectively) were similar to those of major conventional criteria (70 and 94%) and were not improved by combined major/minor European criteria (72 and 90%). When all the minor European criteria were considered, sensitivity increased to 87% but specificity dramatically decreased to 51%. However, one of these minor ECG criteria, deep S V2, was of interest and when added to major European criteria, sensitivity increased to 76% and specificity remained good (90%). CONCLUSIONS: The diagnostic value of new European criteria for HCM was evaluated for the first time. We found that it was not different from that of conventional criteria, with a good specificity but a low sensitivity. Additional criteria should be studied to improve the early identification of HCM.

Adult↗
PubMed2003

Clinical applications of B-type natriuretic peptide (BNP) testing.

Many claims have been made in recent years regarding the utility of plasma B-type natriuretic peptide (BNP) concentration measurements in the diagnosis, risk stratification and monitoring of patients with heart failure. This paper summarizes the current evidence and provides guidance for practising clinicians. Overall, plasma BNP testing appears to be of most value in the diagnostic arena, where it is likely to improve the performance of non-specialist physicians in diagnosing heart failure. In clinical practice, BNP testing is best used as a 'rule out' test for suspected cases of new heart failure in breathless patients presenting to either the outpatient or emergency care settings; it is not a replacement for echocardiography and full cardiological assessment, which will be required for patients with an elevated BNP concentration. Although work is ongoing in establishing the 'normal' values of BNP, heart failure appears to be highly unlikely below a plasma concentration of 100 pg/ml. However, as BNP levels rise with age and are affected by gender, comorbidity and drug therapy, the plasma BNP measurement should not be used in isolation from the clinical context.

Ambulatory Care↗
PubMed2002

[Prognostic value of neurohormones in heart failure in clinical practice].

The decisive therapeutic advances achieved in cardiac insufficiency in recent years have been thanks to drugs affecting the different neurohormonal systems in operation. Neurohormonal activation plays a major role in cardiac insufficiency. Several neuro-endocrine mechanisms exert vasoconstrictor effects: the sympathetic system, the renin-angiotensin-aldosterone system and the endothelins. In cardiac insufficiency these effects are counterbalanced, but insufficiently, by vasodilatory agents, mainly the natiuretic peptides, EDRF (endothelium derived relaxing factor), vasodilatory prostaglandins, bradykinin and adrenomedulin. Neurohormonal activation is an excellent marker of not only the severity but also the prognosis of cardiac insufficiency. Standardisation of dosage is desirable in order to allow the use of neurohormonal drugs in a very large number of centres.

Biomarkers↗
PubMed2001

Alteration of cardiac and renal functions in transgenic mice overexpressing human mineralocorticoid receptor.

The mineralocorticoid receptor (MR), a ligand-dependent transcription factor, mediates aldosterone actions in a large variety of tissues. To explore the functional implication of MR in pathophysiology, transgenic mouse models were generated using the proximal human MR (hMR) promoter to drive expression of hMR in aldosterone target tissues. Tissue-specific analysis of transgene expression in two independent transgenic animal (TG) lines by ribonuclease protection assays revealed that hMR is expressed in all mineralocorticoid-sensitive tissues, most notably in the kidney and the heart. TG exhibit both renal and cardiac abnormalities. Enlarged kidneys were histologically associated with renal tubular dilation and cellular vacuolization whose prevalence increased with aging. Renal clearance studies also disclosed a significant decrease in urinary potassium excretion rate in TG. hMR-expressing animals had normal blood pressure but developed mild dilated cardiomyopathy (increased left ventricle diameters and decreased shortening fraction), which was accompanied by a significant increase in heart rate. Differential gene expression analysis revealed a 2- to 5-fold increase in cardiac expression of atrial natriuretic peptide, serum- and glucocorticoid-induced kinase, and early growth response gene 1 as detected by microarrays; renal serum- and glucocorticoid-induced kinase was also induced significantly. Altogether, TG exhibited specific alteration of renal and cardiac functions, thus providing useful pathophysiological models to gain new insights into the tissue-specific mineralocorticoid signaling pathways.

Animals↗
PubMed2001

[Medical treatment of chronic heart insufficiency].

The treatment of chronic heart failure by alteration of systolic function has made remarkable progress over the past ten years; this progress has been linked to the results of large-scale clinical trials involving tens of thousands of patients. The medical approach to heart failure is therefore based on established clinical data. The therapeutic aims have been extended: not only should treatment relieve the symptoms of the disease, but also reduce the frequency of relapse and hospitalization, and prolong survival duration. At the onset of the third millennium, three therapeutic classes have emerged: conversion enzyme inhibitors, spironolactone, and beta-blockers, which although counter-indicated only a short while ago, now constitute the revolutionary aspect of the approach to treatment of chronic heart failure. In addition to drug therapy and as in the case of other chronic diseases, the significant role of patient awareness, i.e., the information and education that is made available to the individual regarding his or her illness, should also be taken into consideration. Regarding the latter aspect, the experience gained in this field by the care systems can be utilized. However, recent epidemiological data have shown that the advances made in the treatment of heart failure only concern a minority of patients; and that elderly subjects, women, and patients suffering from heart failure in spite of normal systolic function, which constitute the majority of cases, have not been considered in these trials.

Chronic Disease↗
PubMed2001

Thromboembolism in heart failure, old ideas and new challenges.

Until now, the administration of antithrombotic therapy in patients with congestive heart failure has not been well codified. The incidence of thromboembolic complication, such as stroke, peripheral or pulmonary embolism, is regarded as too low to justify the use of anticoagulation in non-selected patients. However, other thrombotic complications may occur especially in patients with ischemic heart failure and represent potential targets for antithrombotic therapy. The objective of this paper is to review the available evidence in the absence of the results of large ongoing trials.

Heart Failure↗
PubMed2000

Prognostic value of neurohormonal activation and cardiopulmonary exercise testing in patients with chronic heart failure.

We compared the value of plasma neurohormones and cardiopulmonary exercise testing for predicting long-term prognosis in patients with moderate congestive heart failure (CHF). We studied 264 consecutive patients with CHF due to left ventricular systolic dysfunction. Plasma atrial natriuretic peptide (ANP), norepinephrine, and endothelin-1 were measured at rest in all patients, who also underwent a symptom-limited maximal exercise with oxygen consumption (VO(2)) determination. After a median follow-up of 789 days, 52 deaths and 31 heart transplantations occurred, of which 4 were urgent. In an univariate analysis, New York Heart Association functional class, systolic blood pressure at rest, left ventricular end-diastolic diameter, left ventricular ejection fraction, peak VO(2), percent of predicted peak VO(2), plasma ANP, plasma norepinephrine, and plasma endothelin-1 were associated with survival without urgent heart transplantation. In a multivariate stepwise regression analysis, only plasma ANP (p = 0.0001), left ventricular ejection fraction (p = 0.007), and plasma norepinephrine (p = 0.035), but neither peak VO(2) nor percentage of predicted peak VO(2), were independent predictors of death or urgent heart transplantation. Determination of plasma ANP and norepinephrine provides additional independent information for long-term prognostic determination compared with exercise testing alone. Measurement of plasma neurohormones should therefore be considered routinely as a complementary or alternative tool for identifying high-risk patients with moderate CHF.

Atrial Natriuretic Factor↗
PubMed2000

Expiratory flow limitation as a determinant of orthopnea in acute left heart failure.

OBJECTIVES: To assess the contribution of expiratory flow limitation (FL) in orthopnea during acute left heart failure (LHF). BACKGROUND: Orthopnea is typical of acute LHF, but its mechanisms are not completely understood. In other settings, such as chronic obstructive pulmonary disease, dyspnea correlates best with expiratory FL and can, therefore, be interpreted as, in part, the result of a hyperinflation-related increased load to the inspiratory muscles. As airway obstruction is common in acute LHF, postural FL could contribute to orthopnea. METHODS: Flow limitation was assessed during quiet breathing by applying a negative pressure at the mouth throughout tidal expiration (negative expiratory pressure [NEP]). Flow limitation was assumed when expiratory flow did not increase during NEP. Twelve patients with acute LHF aged 40-98 years were studied seated and supine and compared with 10 age-matched healthy subjects. RESULTS: Compared with controls, patients had rapid shallow breathing with slightly increased minute ventilation and mean inspiratory flow. Breathing pattern was not influenced by posture. Flow limitation was observed in four patients when seated and in nine patients when supine. In seven cases, FL was induced or aggravated by the supine position. This coincided with orthopnea in six cases. Only one out of the five patients without orthopnea had posture dependent FL. Control subjects did not exhibit FL in either position. CONCLUSIONS: Expiratory FL appears to be common in patients with acute LHF, particularly so when orthopnea is present. Its postural aggravation could contribute to LHF-related orthopnea.

Acute Disease↗
PubMed2000

Traumatic coronary-pulmonary artery fistula, 23 years after a stab wound.

We describe a 50-year-old man with onset of severe hemoptysis and anemia. Twenty-three years earlier, he had undergone a surgical procedure for a left thoracic wound as a result of a knife injury. Current diagnosis of aneurysm of the left ventricle and coronary-pulmonary artery fistula was made after coronary arteriography. The patient underwent resection of the aneurysm and repair of the fistula.

Arterio-Arterial Fistula↗
PubMed2000

Plasma adrenomedullin, a new independent predictor of prognosis in patients with chronic heart failure.

BACKGROUND: Adrenomedullin, a potent endogenous vasodilating and natriuretic peptide, may play an important role in the pathophysiology of chronic heart failure. Plasma levels of immunoreactive adrenomedullin were examined for prediction of prognosis in chronic heart failure. METHODS AND RESULTS: Plasma levels of immunoreactive-ADM (ir-ADM) were measured by radioimmunoassay in 117 chronic heart failure patients with idiopathic or ischaemic cardiomyopathy (mean ejection fraction: 28 +/- 10%, in the NYHA functional class I/II/III/IV:8/73/29/7, and treated with ACE inhibitors and diuretics. Plasma levels of immunoreactive adrenomedullin were significantly increased in chronic heart failure patients by comparison to controls (618 +/- 293 pg x ml(-1) vs 480 +/- 135 pg x ml(-1), P=0.01). During the follow-up period (237 +/- 137 days) 14 cardiovascular deaths and four urgent cardiac transplantations occurred. In the univariate Cox model, immunoreactive adrenomedullin plasma levels were related to prognosis (P=0.004). A multivariate analysis including heart rate, systolic blood pressure, NYHA class, left ventricular ejection fraction, left ventricular echocardiographic end-diastolic diameter, plasma levels of immunoreactive adrenomedullin, endothelin-1, norepinephrine and atrial natriuretic peptide was performed: plasma levels of immunoreactive adrenomedullin (P=0.03), of endothelin-1 (P=0.0001), and systolic blood pressure (P=0.003) were significantly associated with outcome. CONCLUSION: Our results suggest that elevated plasma levels of immunoreactive adrenomedullin are an independent predictor of prognosis in predominantly mild to moderate chronic heart failure treated by conventional therapy and provide additional prognostic information.

Adrenomedullin↗
PubMed2000

[Echocardiographic diagnosis of left intraventricular thrombi: contribution of high frequency probes].

Two-dimensional echocardiography is the reference technique for the diagnosis of left ventricular thrombi. However, it has some limitations due to poor imaging of the apex; location of many thrombi. Apical resolution improvement is possible using a 5 MHz ultrasonic transducer, which may identify 3.5MHz ultrasonic transducer false positive results. In a series of 53 patients with left ventricular dysfunction, we detected 11 thrombi. Using the 5MHz ultrasonic transducer as a reference the sensitivity of the 3.5MHz ultrasonic transducer was 100%, and much greater than that of the 2.5MHz ultrasonic transducer (55%), which was associated with 4 false positive results. The increased sensitivity associated with transducers of higher frequency was however limited by the echogenicity of patients, all the more since we used a medium instead of a short focalisation. Due to its therapeutic consequences, the detection of left ventricular thrombi must be enhanced using 5 MHz ultrasonic transducer, all the more in echogenic patients.

Echocardiography↗
PubMed1999

Perivalvular abscesses associated with endocarditis; clinical features and prognostic factors of overall survival in a series of 233 cases. Perivalvular Abscesses French Multicentre Study.

AIMS: The purposes of this study were to determine the clinical features and to identify prognostic factors of abscesses associated with infective endocarditis. METHODS AND RESULTS: During a 5-year period from January 1989, 233 patients with perivalvular abscesses associated with infective endocarditis were enrolled in a retrospective multicentre study. Of the patients, 213 received medical surgical therapy and 20 medical therapy alone. No causative microorganism could be identified in 31% of cases. Sensitivity for the detection of abscesses was 36 and 80%, respectively using transthoracic and transoesophageal echocardiography. Surgical treatment consisted of primary suture of the abscess (38%), insertion of a felt aortic or mitral ring using Teflon or pericardium (42%), or debridment of the abscess cavity (20%). The 1 month operative mortality was 16%. Actuarial rates for overall survival at 3 and 27 months in operated patients were 75 +/- 10% and 59 +/- 11%, respectively. Increasing patient age, staphylococcal infection, and fistulization of the abscess were found to be independent risk factors in both 1 month and overall operative mortality. Renal failure was a risk factor predictive of operative mortality at 1 month, whereas uncontrolled infection and circumferential abscess were regarded as risk factors predictive of overall operative mortality. CONCLUSION: The data determined prognostic factors of abscesses associated with infective endocarditis.

Abscess↗