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Biomedical subjects

M Brochier

Publications and source records attributed to M Brochier.

At least 73 records · Page 4Linked to original sources

[Paroxysmal sinoatrial tachycardia. Apropos of 44 cases].

44 cases of paroxysmal sinoatrial tachycardia (PAT) due to reentry within the sinus node or between the sinus node and the atrium are reported; these tachycardias are usually quite well tolerated clinically as the rhythm is rarely faster than 140/min and they are often degraded by functional AV block. They can be triggered and terminated by one (or two) atrial stimuli, and reduced by carotid sinus massage but relapse in the short term. They often alternate with a disturbance of atrial excitability in patients who also have binodal disease. Their diagnosis implies endocavitary investigation showing sinusal anterograde atrial activation and atrial and ventricular stimulation to differentiate them from other types of paroxysmal tachycardia, especially those due to reentry involving concealed right sided Kent bundles. Studies of sinus node function by atrial extrastimulus techniques in 38 patients usually showed an isolated and prolonged Zone I followed, without a transitional plateau, by a Zone IV of sinus echos during which the tachycardia could be triggered. This type of tachycardia, without doubt as common as junctional tachycardia, may respond to treatment with Quinidine, Amiodarone, Verapamil, or beta-blockers, associated with permanent pacing in cases of binodal block.

Adult↗

[Study of dynamics and left ventricular function using radioisotopic technics in the heart cavities].

The imaging of the cardiac cavities with appropriate tracer materials (99 m Technetium or 113 m Indium), the recording of intracardiac dilution curves by radionuclide angiography and dynamic studies by gamma cinecardiography give global and regional parameters of left ventricular function which are reliable and reproducible: an index of cardiac output, intracardiac circulation times and ventricular volumes. The assessment of left ventricular contraction and global and regional ejection fractions is facilitated by coupling the gamma camera and the electrocardiogramme and computer analysis of the results. "First passage" recordings may be used to differentiate the right from the left heart chambers. "Equilibrium" studies give detailed information at rest, under stress (or leg-raising) and under pacing and/or trinitrin. Average and maximal rates of contraction derived from the ejection fraction and left ventricular contraction times are indices comparable to the rate of fibre shortening. The calculation or regional parameters point by point such as the ejection fraction, contraction time and ejection volume gives a more accurate and sensitive estimation of left ventricular function than the global left ventricular indices. They are many practical applications in cardiology especially in coronary artery disease: monitoring the changes in the acute phase of myocardial infarction, the selection of patients for aorto-coronary bypass surgery and their pre- and post-operative controls. These non-invasive, easy and reliable cardiac studies justify the development of laboratories of nuclear cardiology within departments of cardiac physiological investigation.

Animals↗

[Retrograde ventriculo-auricular heart conduction in 126 patients with or without supra-ventricular paroxysmal tachydardia, with or without ventricular preexcitation].

Ventriculo-atrial (VA) conduction was studied by ventricular stimulation at increasing rate and atrial mapping in 126 patients either without ventricular preexcitation (WPW) and supraventricular tachycardia (SVT) (Group I: 60 cases) or with the WPW syndrome with or without SVT (Group II: 30 cases) or with SVT without WPW (Group III: 53 cases) or with short PR intervals (Group IV: 3 cases). In Group I, 22 patients had VA block, 10 had concealed accessory pathways and 28 had nodal VA conduction. In Group II, 2 patients had VA block, 6 had nodal VA conduction and 22 had preferential retrograde conduction through the Kent bundle. In Group III, 9 patients had concealed Kent bundles and 24 had nodal retrograde conduction. In Group IV, the results were varied. The characteristics of retrograde VA conduction are therefore often different from those of anterograde conduction. 52 attacks of SVT were recorded; in the 18 cases of Group II, 5 septal, 3 right lateral, 8 left lateral Kent bundles and 2 intranodal reentries were demonstrated. In the 33 cases of SVT without overt WPW (Group III) a concealed accessory pathway was demonstrated in 9 cases. In all, approximately a half (25 out of 52) of all SVT were due to reentry involving an accessory pathway which was concealed in about one third of cases (9 out of 25) and more often situated on the left border than on the right or in the septum.

Adolescent↗

[Chronic idiopathic binodal block. Occurrence, course and pathogenesis].

The incidence of binodal, sinoatrial (SA) and atrioventricular (AV), block was determined in a series of 362 patients, 90 of whom had chronic sinoatrial block (group I), 162 suprahisian, infrahisian or diffuse AV block (group II), 38 with paroxysmal supraventricular tachycardia (group III), and 70 with slow atrial fibrillation, 54 of whom were studied in sinus rhythm (group IV). Electrophysiological investigation revealed: overt or latent AV block in 71% of group I, 48% of group III, and 100% of group IV; overt or latent SA block in 40 to 61% of group II, 87% of group III and 78% of group IV; paroxysmal atrial fibrillation in 61% of group I, 25% of group II and 50% of group IV; intra-atrial block in 26% of group I, 20% of group II, 16% of group III and 31% group IV. An ECG syndrome associating binodal block and disturbances or atrial conduction and excitability is suggested. The pathogenesis and anatomical basis are discussed, the prime lesion of which may be fibrosis of the atrial tissues which may ultimately result in partial or total atrial standstill.

Adult↗

[Adult familial idiopathic binodal block].

Four brothers with a maximum age difference of 20 years, the eldest of whom has been re-examined after a 10 year interval, have sinoatrial block, a supra-hisian atrioventricular block and paroxysmal atrial arrhythmias which have led to partial atrial standstill in the eldest: left anterior hemiblock is also present in the two youngest brothers. The condition is very well tolerated. This family is compared to the other 12 reported cases of familial idiopathic binodal block in the adult, an autosomal dominant condition with variable penetration. The diagnosis is reserved and justifies endocavitary investigation of the sinus node function and atrioventricular conduction in the four brothers and the most exposed members of their family. The mechanism of the condition is unknown. It seems to arise from variable degrees of nonspecific of the nodal and atrial tissues.

Adult↗

Topograhic relation between the myocardial uptake of radiothallium and left ventricular kinetics in myocardial infarction.

Myocardial images with thallium 201 are recorded on a computer with the ECG tracing and the cardiac cycle divided into 16 consecutive images. The patients then recieve 99Tcm albumin for first pass and a subsequent ECG gated series for comparison with the myocardial studies. These images can be superimposed and allow the topographic relationships of thallium uptake and ventricular contractility as reflected by the blood pool, to be seen. Quantitative parameters such as ejection fraction and stroke volume are also obtained. Examples in clinical practice are given.

Adult↗

[Moderate doses of urokinase (UK) in the treatment of myocardial infarct and pulmonary embolism].

Since 1972, UK in moderate doses have been used in the treatment of severe or massive pulmonary emboli (PE) and of myocardial infarction (MI) present for less than 24 hours. The standard dose is 2,700,000 CTA units per 24 hours administered as a continuous infusion, in association with appropriate heparin therapy and a platelet anti-aggregant agent in order to palliate the hyperagregant effects of thrombolytic drugs. Laboratory surveillance has now been greatly simplified and is limited to that of the associated heparin therapy. In the acute phase of myocardial infarction, a personal randomised study of 120 cases consisting of 60 treated with heparin + UK and 60 with heparin alone showed that UK decreased mortality, cardiac arrhythmias and cardiac failure. Comparative studies at lower doses have failed to show any significant difference between the two groups of patients treated and the authors feel that the use of UK should be reserved for very recent infarctions in young subjects. In PE, the effectiveness of UK was assessed in 180 severe cases. It depended upon the length of time for which the thrombus had been present. Before the 5th day, there was early average revascularisation of 40 p. 100 of the avascular territory. Mortality was reduced to 15 p. 100 and at the 3rd week 32 p. 100 of the survivors had complete revascularisation, and 68 p. 100 partial but adequate revascularisation. Adjuvant therapy such as a combination of Lysil Plasminogen and/or defibrinating agent currently make it possible to reinforce therapeutic thrombolysis.

Clinical Trials as Topic↗

The contribution of nuclear medicine and ultrasounds in cardiac surgery.

The constant progress in surgical techniques during the last few years have prepared the way for important developments in the field of noninvasive cardiac exploration. Their non-traumatic character, appreciable in diagnostic and preoperative examinations, become indipensable whenever there is a need to repeat the examination in order to evaluate the effects of a treatment or to monitor progress both in the short and long term. In order that such methods be adopted in cardiac surgery it is important that not only must they be without risk but also that the results obtained be clearly presented, if possible in the form of images, and allow a quantitative interpretation. It is necessary also that the results can be justified both by clinical experience and also by comparison with other examinations. No procedure, not even radiologic, can at the same time explore the myocardium and its perfusion, the central circulation and the cardiac haemodynamics. By reason of their respective principles, radioisotopic methods and ultrasounds tackle cardiac problems in different ways and facilitate, by appropriate choice of methods, the selection of one diagnostic response from among several. This paper contains first of all, a resume of the principal nuclear and ultrasonic techniques used together with their basic principles. Next we try to show how these non-invasive techniques, most with dynamic imaging, can assist cardiac surgery. For this, we successively look at the different pathologies, working from the exterior (pericardium) towards the interior (intracardiac structures and central circulation) and covering the different aspects of the myocardial pathology. In each case the mutual contributions of physical techniques is specified as well as the preference for either isotopic or ultrasonic methods.

Angiocardiography↗

[Comparative study of left ventricular kinetics by gamma-cinecardiography and ventriculography].

50 patients were investigated by both left ventricular cine-angiography, and "balanced" gamma-cine-cardiography in the frontal and LAO positions. Measurements of the ejection fraction and the mean and maximal speeds of contraction were made by the two techniques. The correlation was good (r = 0.89 for the ejection fraction). A morphological analysis of the dynamic findings in the two methods in the 12 cases with discordered left ventricular kinetics showed that once again the results were very similar. A numerical presentation of the data from the radioisotope studies was made either as a group of sequential ventricular contours successively from diastole to systole, or to give a functional picture which would provide the value for one kinetic paramter at any one time (for example, the regional equivalent of the ejection fraction). To overcome the problems of superimposition in the RAO position in the "balanced" technique, the recordings of the first radioisotope study in RAO were combined with a study of balance in 50 other patients, and the correlation was excellent. These two isotope techniques, which can be carried out in the same examination and which may be repeated without risk, perfectly complement each other, and very few of the results were incapable of interpretation.

Adult↗