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Biomedical subjects

R Haïat

Publications and source records attributed to R Haïat.

At least 19 recordsLinked to original sources

[False aneurysm of the left ventricle during the acute phase of myocardial infarction: diagnosis by transesophageal echocardiography].

The authors report a case of myocardial infarction complicated by a false aneurysm of the posterior wall of the left ventricle, the diagnosis of which was confirmed, for the first time, by transesophageal echocardiography (TEE) which provided better definition of the anatomical features of the lesion: visualisation of the particularly wide neck (5 cm) and the site of rupture of the myocardium; demonstration of the presence in the false aneurysm with a thin pericardial wall of a large thrombus of different acoustic density, itself overlain by swirling whorls. Colour Doppler combined with TEE clearly showed the acceleration of flow at the neck and its slowing in the newly formed cavity. Once the diagnosis was made, the patient rapidly underwent surgery with a successful outcome. The quality of the images obtained without risk by TEE suggests the important role which this investigation could play in the future in the diagnosis of certain mechanical complications of myocardial infarction.

Diagnosis, Differential

[Evaluation of treatments with beta-blockaders after myocardial infarction].

Beta-blockers have been used after myocardial infarction since 1965: however, it was not until the beginning of the 80s that the large multicentre clinical trials published results showing clearly their beneficial effects and leading to their widespread usage: betablockers significantly reduce the medium term (1 to 3 years) risk of death (-22 to -24%), especially sudden death (-32%) and the frequency of recurrent infarction (-27%). The cardio-protection so obtained is multifactorial, essentially related to their antiarrhythmic, antiischemic and antihypertensive effects. It has been established that beta-blockade should be instituted as soon as possible in the hours following the infarct (intravenous relayed by oral administration) and may be useful associated with aspirin. Although the large scale clinical trials did not determine the optimal dosage or the duration for which treatment should be administered, they did show that the groups of high risk patients were those to benefit the most from this therapy. Beta-blockers are usually well tolerated. However, it must be pointed out that 18% of patients were excluded from the two principal trials (only 25 to 30% of infarct patients were included) because of contraindications to beta-blockers and that 25 to 30% of the patients initially included had to interrupt the treatment because of side effects.

Adrenergic beta-Antagonists

[Electrocardiogram during the initial period of myocardial infarction: a tool of therapeutic decision].

The electrocardiogram (ECG) remains the basic investigation for the diagnosis of acute myocardial infarction. The decision to institute intravenous thrombolytic therapy, which has revolutionised the treatment of myocardial infarction in recent years, requires the presence of ST segment elevation and a suggestive clinical history. Early Q waves and reciprocal ST changes may be helpful. The value of thrombolytic therapy has not been demonstrated in patients without ST elevation, especially considering the usually favourable prognosis of infarcts with normal ECGs or with only non-specific repolarisation changes. The initial ECG provides information about infarct size which is an essential prognostic factor. This evaluation is based on the topography (anterior or inferior), the amplitude of ST elevation and the number of leads in which these changes are observed. The initial analysis has two objectives: to evaluate the risk/benefit ratio of treatment in cases of relative contraindications to thrombolysis or with a doubtful diagnosis; to select high risk patients (extensive infarcts) who may benefit from "salvage angioplasty" in the event of failure of thrombolysis: coronary angiography should be programmed from the onset as the ECG outcome does not allow prediction of the results of thrombolysis for the majority of these patients.

Decision Support Techniques

[Heparin in the treatment and secondary prevention of myocardial infarction. A critical review of the main trials].

The aim of this article is to assess the therapeutic value of standard heparin in the acute phase and secondary prevention of myocardial infarction. Only clinical trials with an adequate methodology have been analysed. In patients having undergone thrombolytic therapy associated with aspirin, heparin slightly reduces the mortality but only during the period of its administration. In a metaanalysis of approximately twenty clinical trials of patients not receiving thrombolytic or aspirin therapy, heparin was associated with a significant reduction of deep vein thrombosis, pulmonary embolism, recurrent myocardial infarction and cerebrovascular accidents. In the context of secondary prevention of myocardial infarction, the administration of a moderate dose of subcutaneous heparin resulted in a beneficial effect on morbidity and mortality in one published trial. The use of low molecular weight heparins for the prevention of coronary thrombosis merits attention because of the pharmacological and pharmacokinetic properties of these products.

Cerebrovascular Disorders

[Angina at rest without significant changes in the per-critical ECG in coronary insufficiency].

In coronary patients angina pectoris at rest is usually attended by clear changes in repolarization, and in the absence of such changes clinicians are justifiably reluctant to assert that the constrictive chest pain is due to ischaemia. However, a number of concordant data indicates that in some cases myocardial ischaemia--whether spontaneous or induced by the ergonovine test or by coronary angioplasty--may cause an anginal pain that proceeds without significant alterations in repolarization and indeed, without any changes in ECG tracings. Prior to making a firm diagnosis of this type of angina, several causes of error must be excluded, the main one being that repolarization disorders are labile and may have disappeared whilst the anginal pain persists. But above all, the ischaemic episode that accompanies angina must be documented by haemodynamic, angiographic, scintigraphic or echocardiographic data. The pathogenesis of angina at rest occurring in coronary patients and without changes in per-critical ECG is still imperfectly known and probably complex. The authors review several possible mechanisms: the pain perception threshold may be lowered, the collateral circulation may be highly developed, and the ischaemic episode may be so discreet and/or controlled by treatment, or so evenly distributed between two opposite territories that no electric gradient is generated.

Angina Pectoris

[Anomalies of the T waves induced by flecainide].

Flecainide is a class I antiarrhythmic agent which depresses depolarization and conduction velocities in myocardial and Purkinje's fibres, thereby extending their refractory period. As the drug belongs to the IC group, it may increase--moderately as a rule--the duration of QRS, but it does not alter the action potential duration and therefore does not increase the JT interval. In 3 patients treated with flecainide we observed a peculiar alteration in the shape of T waves, the peak of which was flattened and notched, forming a double hump. This abnormality, most clearly visible on precordial leads, remained isolated with no changes in other electrocardiographic parameters. It appeared independently of any circumstance likely to modify repolarization. It remained stable throughout treatment with flecainide and vanished when the drug was discontinued. It was regularly observed with the recommended therapeutic doses (200-300 mg/day) and was unaccompanied by signs of toxicity. To our knowledge, these T wave abnormalities have not yet been reported. Yet they deserve to be known and correctly interpreted, since they reflect impregnation of the myocardium by the antiarrhythmic agent which should not be withdrawn on this account.

Adult

[Aneurysm of the interauricular septum].

In reference to three personal cases of interatrial septum aneurysm discovered on ultrasonography performed for the diagnosis of a cerebral embolism, the authors describe the positive diagnosis criteria, in mono- and bi-dimensional mode, of this abnormality, as well as related data obtained from catheterization, angiocardiography, and phonocardiography. This malformation, the frequency and pathogenesis of which still remain, today, difficult to evaluate, may be at the origin of complications, especially embolic migrations, systemic and also pulmonary, supraventricular rhythm disorders, interatrial shunt, reduced ventricular filling. Once established, the diagnosis is the subject of many controversies: if plain monitoring appears logical in asymptomatic forms, the occurrence of a systemic embolism makes it difficult to choose between surgical treatment and long-term anticoagulant therapy.

Aged

[Value of echocardiography in the study of the embolic origin of a cerebral ischemic accident].

One hundred consecutive patients aged from 35 to 82 years (mean : 74 years) admitted to a Neurology unit for cerebral ischaemic accident of suspected embolic origin were examined by two-dimensional echocardiography, then divided into two groups. Group I patients (n = 24) had a cardiopathy detectable by ultrasound, such as valve disease (n = 5), ischaemic cardiopathy (n = 10), myocardial dilatation (n = 4) or hypertrophic obstructive cardiomyopathy (n = 1). Group II patients (n = 74) had no cardiopathy detectable by ultrasound. Among group I patients, a thrombus was detected in 3 cases (12.5%), and 16 patients (66.7%) had echographic signs of potentially emboligenic cardiopathy without thrombus, including mitral or aortic valve stenosis (5 cases), parietal ectasia (6 cases), severe abnormality in left ventricular contractility (4 cases) and left atrial dilatation (4 cases). No thrombus was visualized in group II patients, but 10 (13.2%) had signs of potentially emboligenic cardiopathy, including mitral valve prolapse in 6 and left atrial dilatation in 4 cases. Altogether, therefore, a potentially emboligenic cardiopathy was detected by echocardiography in 29% of these 100 patients, but it had already been diagnosed prior to this examination in 24%. A thrombus could be visualized in only 3% of the cases. It is concluded that echocardiography need not be systematically performed in all patients with cerebral ischaemic accident, but only in young patients in search of a cause amenable to curative or actively prophylactic treatment.

Adult

[The exercise electrocardiogram after the acute phase of myocardial infection. Analysis of 100 cases].

A study was made of the effort electrocardiogram (ECG) of 100 patients who had had a myocardial infarction and correlated in 46 cases with findings at coronography. Angina occurred in 38 cases. The ECG remained stable in 17 cases and showed changes in 83. In 60 patients, in those leads with pathological Q waves, isolated T wave changes (15 cases), ST elevation (43 cases) or ST depression were seen. In 17 cases there was isolated ST depression in leads free of any signs of infarction. In 6 cases alterations in rhythm or conduction were seen.

Angina Pectoris

Transient ST segment elevation occurring without anginal pain. Correlations with Prinzmetal's angina.

Two cases presenting with episodes of marked ST segment elevation occurring with, but most often without, anginal pain are reported. The changes were recorded through continuous ECG monitoring during Prinzmetal's angina and in the course of myocardial infarction. Such transient asymptomatic ECG abnormalities reveal silent acute myocardial ischemia and are often unrecognized. However, they may lead to severe arrhythmias or myocardial infarction, and sudden deaths occurring in the course of ischemic heart disease are likely to be explained on this basis. Transient episodes of silent ST segment elevation similar to those occurring in Prinztal's angina have been reported in various circumstances. They bring into discussion the delimitations of variant angina pectoris.

Aged