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Biomedical subjects

C Guérot

Publications and source records attributed to C Guérot.

At least 19 recordsLinked to original sources

Clinical study of the effects of latissimus dorsi muscle flap stimulation after cardiomyoplasty.

BACKGROUND: Beneficial hemodynamic effects after dynamic cardiomyoplasty have been inconsistently demonstrated, and the effects seen may be due to the wrap itself, to flap stimulation, or both. The aim of this study was to determine whether flap stimulation per se acts as a systolic active process after cardiomyoplasty. METHODS AND RESULTS: Catheterizations were performed in 13 patients 14.4 +/- 7 months after cardiomyoplasty. New York Heart Association functional class decreased from 3.3 to 2.1 after the procedure (P = .0005). Hemodynamic evaluations were first performed with the stimulator on in the 2:1 mode and then after the stimulator had been off for at least 24 hours. Left ventricular (LV) ejection fraction increased from 25.1 +/- 6% before surgery to 28.2 +/- 6.7% with the stimulator on after cardiomyoplasty (P = .04). When stimulation was stopped, there was no change (P > .05) in indexes of systolic or diastolic LV function (peak systolic LV pressure, LV ejection fraction, peak positive dP/dt, peak negative dP/dt, or tau). Pulmonary capillary wedge pressure and cardiac index were unchanged when stimulated and nonstimulated settings were compared (P > .05). However, a remarkable heterogeneity of individual responses was observed. Ejection fraction and cardiac index decreased with the stimulator off in 3 patients, but peak positive dP/dt decreased in 6 patients; diastolic function deteriorated in 2 patients, but a slight improvement was noted in 3 patients. Cardiothoracic ratio, echocardiographic LV end-diastolic dimension, and fractional shortening remained unchanged between immediate (< 1 month) and long-term (36.7 +/- 25.9 months) postoperative evaluations. CONCLUSIONS: In the majority of our patients, there was no short-term hemodynamic benefit of flap stimulation; therefore, we conclude that the efficacy of cardiomyoplasty may be a consequence of a passive "girdling effect," which limits the progression of ventricular enlargement and further deterioration of ejection fraction.

Adult

[Value and limitations of methods for measuring left ventricular mass].

M-mode echocardiographic measurement of the left ventricular mass is inaccurate when the hypertrophy is asymmetric and the ventricule very deformed. The routine calculation of the mass is based on several hypotheses, verified in normal and hypertensive subjects: the standard error (SEE) is 30-40 g, 10-15% (r > 0.9). The standard deviation of inter-examination differences (> 25 +/- 30 g with a variation coefficient c = 10-15%) makes it difficult to appreciate variations of mass in a given patient. Two-dimensional echocardiographic measurement of left ventricular mass requires the use of geometric formulae which have not been validated in the cardiomyopathies. The absence of a consensus on the models used has favorized the use of MRI and of ultrafast computed tomography. MRI measurement of mass has been validated in normal and ischaemic hearts (r > 0.97, SEE < 8 g, c = 15%) but the times of acquisition are long. Using ultrafast CT, not universally available, this measurement has been validated in vivo and in vitro, including in cardiomyopathy for which the SEE is low (6%) and reproducibility excellent (c = 4-8%), comparable with results in normal subjects.

Angiocardiography

[Hypertrophic cardiomyopathy: place and limitations of medical therapy].

The development of echocardiography and kindred studies have enabled the detection of an increasing number of asymptomatic forms of hypertrophic cardiomyopathy. Drug therapy, by far the commonest therapeutic method of managing this condition, has only been shown to be effective on the symptoms. Therefore, due to the risk of iatrogenic disease, medication is only proposed to symptomatic patients: high dose betablockers is the usual treatment; when ineffective or contra-indicated, verapamil may be prescribed at progressively increasing doses under strict medical control. These products may need to be given at high doses in order to be effective but excessive bradycardia may be a limiting factor. Amiodarone alone or in association, may be preferred in forms with arrhythmias. The comparative efficacy of the different drugs, especially in preventing sudden death, requires well designed, controlled, therapeutic trials. Their results, if positive, would question the dogma of only treating symptomatic patients.

Adrenergic beta-Antagonists

[Hormone replacement therapy in postmenopausal women and cardiovascular risk].

Although the cardiovascular effects of hormone replacement therapy of menopause have been controversial for a long time, the benefit of this treatment currently appears to be well established, despite the methodological problems of most studies and the absence of definitive demonstration by a prospective randomized study. The mechanism of this favourable action appears to be multifactorial with, in particular, an improvement of the lipid profile. In the absence of any gynaecological contraindication, the combination of a natural oestrogen and a progestogen devoid of any androgenic effect therefore appears to be the preferable treatment in postmenopausal women, especially as its cardiological value is added to other important and clearly documented actions.

Aged

[How to evaluate a patient with heart failure? Round table].

Evaluation of heart failure is the first step prior to introduction of an adapted therapeutic strategy. Three principal objectives must be defined: 1) identify the cause of heart failure, which may directly guide subsequent treatment (valvular heart disease, coronary artery disease, etc.); 2) evaluate the repercussions of heart failure on everyday life: evaluation of quality of life, severity of functional disorders and reduction of the everyday capacity. This evaluation is the most delicate as it is based on clinical interview: evaluation of the various NYHA stages lacks precision and reproducibility. The stress test with measurement of oxygen consumption appears to constitute an acceptable evaluation technique; 3) evaluation of the prognosis. Many studies have demonstrated precise relationships between life expectancy and a number of criteria, alteration of myocardial function, echocardiographic findings, ejection fraction, cardiac output and even an AP chest x-ray. Although statistically valid, these criteria have a limited application in individual patients. Evaluation of all these parameters is the most accurate way to predict the subsequent course of the disease which therefore allows a more accurate choice of treatment and subsequent evaluation of their efficacy.

Heart Failure

[What is left of invasive electrophysiological explorations?].

After a golden period during which invasive electrophysiological investigations improved our understanding of the physiopathology of cardiac arrhythmias the clinical indications have now become more restricted. In the investigation of syncope, electrophysiological studies are only envisaged when the diagnosis is uncertain after clinical examination, resting ECG and non-invasive investigations. Holter monitoring in particular. Three types of arrhythmia may confirm our positive diagnostic criteria: sinoatrial block in patients with a sinus node recovery time greater than 1,000 ms uninfluenced by atropine atrioventricular block in patients with distal conduction defects during sustained atrial pacing, if necessary after injection of ajmaline: ventricular tachycardia in patients sustained monomorphic VT induced by 2 or 3 extrastimuli. The selection of the clinical indications has significantly improved the diagnostic value of electrophysiological investigations. The negativity of a strictly performed protocol, even though not giving a precise diagnosis of a syncopal episode, does provide reassuring prognostic information. In VT, electrophysiological studies may also be used to evaluate the secondary prognosis but with a diagnostic value no greater than that of non-invasive investigations. Programmed ventricular stimulation is not systematic for guiding antiarrhythmic therapy in France. Reserved for recurrent VT, electrophysiological studies are of additional value in the adaptation of treatment and improve the secondary prognosis.

Arrhythmias, Cardiac

[Spasm of the left main coronary artery resistant to intracoronary vasodilators. Apropos of a case].

Coronary spasm is essentially and angiographic diagnosis. Catheter-induced spasm is frequent during coronary angiography and usually regresses after the administration of intracoronary vasodilators. The authors report a case of coronary spasm with subocclusion of the left main coronary artery: the coronary narrowing remained significant after intracoronary vasodilator therapy, suggesting an organic component. The spasm was relieved only after a prolonged intravenous infusion of isosorbide dinitrate.

Angina Pectoris, Variant

[Retrograde dissection of the common trunk of the left coronary vessel during angioplasty of left anterior descending coronary artery. Apropos of 2 cases].

Acute dissection of the left main coronary artery during coronary angiography or angioplasty is a rare but well known complication; it is attributed to a mechanical trauma caused by the tip of the catheter guide wire. The authors present two cases of dissection at the site of coronary angioplasty with a retrograde extension to the left main stem requiring emergency coronary surgery.

Aged

[Dynamic cardiomyoplasty. Hemodynamic study of 3 patients].

Dynamic cardiomyoplasty is a surgical operation aimed at compensating for a loss of substance or a severe deficiency of the left ventricular myocardium by implanting around the heart the latissimus dorsi muscle the contraction of which, synchronous with that of the ventricles, acts on the heart in the manner of a massage or milking. The operation, which in its present form is recent, consists of applying Onto the heart, or wrapping that organ with, a skeletal muscle that keeps its neurovascular supply and its high insertion, and of installing the appropriate electrodes and a pacemaker. We report the haemodynamic data collected in 3 patients operated upon for severe cardiac failure 13, 8 and 9 months ago respectively and who are now in NYHA functional stages I and II. During 1/1 stimulation of the latissimus dorsi systolic pressures remain unchanged while diastolic pressures rise; cardiac output increases satisfactorily in two of the patients (cases No. 1 and 3) and is unmodified in the third one (case No. 2). We conclude that cardiomyoplasty seems to give favourable results but its future and indications remain to be determined.

Adult

[Surgical mitral valvuloplasty and dynamic left ventricular obstruction syndrome].

The "dynamic" left ventricular outflow obstruction syndrome, which is found in 4.5 to 11 p. 100 of patients who underwent mitral valve repair by Carpentier's technique, seems to be due to the association of two different sets of circumstances. The first set is anatomical; the syndrome is thought to result from the implantation of a semi-rigid valve ring, from the excessive length of the mitral valve system in relation to the size of the ventricular cavity, and from excessive correction of mitral regurgitation with subsequent excessive reduction in caliber of the left ventricular outflow tract, change in the interrelation between outflow tract and ventricular filling and strongly anterior position of the mitral valve. The second set is functional; it is due to a more than 20 p. 100 reduction in caliber of the left ventricular outflow tract on the one hand, and to a more than 2.5 m/s increase in blood flow velocity on the other hand. These two phenomena may be produced by a decrease in left ventricular volume as a result of hypovolaemia, tachycardia or more rapid circulation. Treatment of the syndrome consists of correcting the associated abnormalities by prescribing a diet with a normal sodium content, together with an appropriate anti-arrhythmic agent and a beta-blocker.

Adult

[Congenital atrioventricular block and maternal lupus erythematosus. Histologic discovery of tumor of the atrioventricular node].

A case of congenital atrioventricular block in a newborn whose mother presented with systemic lupus erythematosus (SLE) is reported. Despite intensive care the child died a few hours after birth. Serial sections of the heart could be examined. Histology provided information on the appearance and distribution of the lesions. In particular, the sinus node was small for the child's age, and its supplying artery was found to have a hyperplastic media with adventitial sclerosis; the interatrial and interventricular septa showed subendocardial fibrosis invading the adjacent myocardium. Owing to the scarcity of systematic histopathological examinations, such lesions have seldom been described. In addition, a tumour of the atrioventricular node, known as mesothelioma or hemolymphangioma, was discovered. This case is exceptional in that histopathological findings similar to those described in SLE, though rarely as numerous, were associated with a very rare tumour never hitherto described in such a young patient. The relationship between the two categories of lesions is discussed.

Adult

[Sick sinus syndrome in children with a "healthy heart". Apropos of 2 cases with direct endocavitory tracing of the sino-atrial block].

The sinus disease in children with "healthy hearts" is exceptional, and has never been documented by tracing of the sinus node. We are reporting two cases of two children, aged 4 and 14 years. An electrophysiological exploration with measurement of the direct activity of the sinus node, illustrates in one case the mechanism of sinus dysfunction. A review from the literature and our cases specifies some of the characteristics of this disease: 1) there are two forms: sporadic (case n. 1) 59 published cases, and familial (case n. 2) 28 published cases in 13 families; 2) the familial forms have a dominant autosomic transmission with variable penetration; 3) the disease may occur during the first days of life, suggesting a congenital origin (from the pathology findings, this disease may be one of the causes of the unexplained sudden death syndrome in infants; 4) association to atrio-ventricular conduction disorders and atrial and ventricular rhythm disorders; 5) frequent indication of stimulators, emphasizing the severity of this disease with a more severe course in sporadic forms (7 deaths in 59 cases).

Adolescent

[Double valve replacement in a 30-year-old man with acute systemic lupus erythematosus].

A 30 year old man presenting with a 10 year history of delayed pressure urticaria had a secondary lupus-induced double mitral and aortic regurgitation which necessitated double valve replacement within 2 years. The anatomical appearances of the valvular lesions were very unusual and suggest a new anatomo-clinical form of the classical Libman-Sacks endocarditis. In addition to infective endocarditis, systemic lupus erythematosus may also lead to valvular lesions necessitating valve replacement. The association of S.L.E. and delayed urticaria is rare, and also merits publication.

Acute Disease

Pentosane polysulfate: the effect on hemostasis of a continuous 3-day infusion.

Pentosane polysulfate (PP) is a sulfated polysaccharide known to exhibit anticoagulant properties that are in part independent of antithrombin III activity. These effects have only been studied in vitro or after single injections in healthy subjects. Our objective was to evaluate the modification of hemostasis induced by a 3-day continuous infusion of PP (4 mg/kg body weight/24 hr) in 10 subjects. No hemorrhagic complication was observed in any patient. Bleeding time was not modified by the infusion, despite a slight decrease in the platelet number. Among the other parameters measured, the automated partial thromboplastin time, prothrombin time, and anti-Xa activity were the most affected by PP. The kinetics of their modifications were quite uniform: clotting times and the anti-Xa effect increased gradually until reaching steady state 24 hours after the start of the infusion. A progressive return to the pretreatment level was then observed during the 6 hours after the end of the infusion. A significant decrease in the factor V concentration was found at day 4. Finally, in contrast with other reported results, no activation of fibrinolysis was induced by PP under the conditions we used, which suggests that discontinuous administration or the route of administration of the drug influences the fibrinolytic effect. In conclusion, we show the excellent tolerance of continuous infusion of PP, detail the modifications in biologic parameters of hemostasis during and after PP infusion, and demonstrate that PP decreases factor V activity.

Adult

[Detection of anterior interventricular involvement after primary posterior wall infarct].

Forty-five patients (average age 53.3 +/- 9.4 years) underwent exercise stress testing coupled with exercise myocardial scintigraphy and right heart catheterisation on exercise during the 3rd week after primary posterior wall infarction. Coronary angiography and ventriculography were carried out 24 to 48 hours later. Significant (greater than or equal to 75%) left anterior descending disease was present in 9 patients (Group I) and absent in 36 patients (Group II). Tolerance of maximal exercise stress testing was good in all patients. The results were uninterpretable in on third of the cases because the theoretical maximal heart rate was not attained. No significant difference was noted between groups I and II with respect to: mean age, percentage of theoretical maximal heart rate attained, mean pulmonary capillary pressures at rest and during exercise, basal and exercise cardiac index, end diastolic index and angiographic left ventricular ejection fraction. The sensitivity and specificity for the detection of LAD disease were 80% and 84% for the exercise stress testing (n = 30), 44% and 75% for exercise right heart catheterisation (n = 30), 60% and 92% for exercise myocardial scintigraphy (n = 30), 100% and 75% for combined exercise stress testing and myocardial scintigraphy (n = 30) and 78% and 64% for combined exercise stress testing and myocardial scintigraphy and exercise right heart catheterisation (n = 45). These results show that in patients capable of performing maximal exercise stress tests, the best method of early detection of significant LAD disease after primary posterior infarction was combined exercise stress testing and exercise myocardial scintigraphy. These investigations are useful for the selection of candidates for coronary angiography.

Adult

[Early interruption of antiarrhythmia treatment in the acute phase of infarction complicated by ventricular arrhythmia].

18 patients with myocardial infarction complicated by severe ventricular arrhythmias (polymorphic VEBs or bigeminy = 5; VT = 11; VF = 2) were treated with antiarrhythmics which were stopped after 24 hours (intravenous infusion of mexiletine 0.5 mg/kg/hr after a loading dose). This treatment resulted in one failure (recurrent VF) and 17 successes, after increasing the dose in 3 cases of VT. After stopping treatment, 72% of patients had no further arrhythmia. 5 cases had recurrent VT within 72 hours, which was controlled by oral mexiletine in 4 cases. The ejection fraction was significantly decreased in the group with recurrent VT. Plasma assays were of little help. Stopping the antiarrhythmic treatment after 24 hours does not therefore present any particular risks and can be proposed even in cases with severe arrhythmias.

Arrhythmias, Cardiac

[Right intraventricular tumors. Apropos of a case].

The authors report a case of right ventricular tumour in a 16 year old girl who presented with dyspnoea on effort, chest pain on exertion and loss of consciousness. The diagnosis was made on the basis of abnormal right intraventricular echoes on two dimensional echocardiography and was confirmed by angiography. The patient was operated with success. Histology revealed a mesenchymoma, a benign tumour, but whose infiltrating nature calls for a reserved prognosis. The echocardiogram can be used for regular post-operative surveillance. The young patient is well after 18 months' follow-up.

Adolescent