[Does mitral insufficiency prevent spontaneous contrast phenomenon and formation of thrombi in the left atrium?]. / L'insuffisance mitrale prévient-elle la formation du phénomène de contraste spontané et la constitution des thrombus dans l'oreillette gauche?

The aim of this study was to assess the influence of mitral regurgitation on the prevalence of left atrial spontaneous echo contrast and thrombosis in 2,180 consecutive patients undergoing transthoracic and transoesophageal echocardiography. Two groups of patients were defined according to the absence (group I) or presence (group II) of grades 3 or 4 mitral regurgitation quantified by transoesophageal echocardiography. Group II was associated with a statistically significant lower frequency of spontaneous echo contrast (0.6 vs 11.2%; p < 0.0001), left atrial thrombosis (0.6 vs 4.2%; p < 0.03), ischaemic cerebrovascular accidents (1.2 vs 21%; p < 0.0001), transient ischaemic attacks (0 vs 12%; p < 0.0001) and systemic embolism (0 vs 4.6%; p < 0.01). Conversely, the prevalence of atrial fibrillation was higher in group II (28 vs 19%; p < 0.01) and there were more patients with left atrial dimensions > or = 5.5 cm (16 vs 6.7%; p < 0.0001). When mitral stenosis and valve prosthesis were excluded, there were no cases of spontaneous echo contrast (8.3 vs 0%; p < 0.001) or left atrial thrombosis (2.9 vs 0%; p < 0.05) in the group with grades 3 or 4 mitral regurgitation. The phenomenon of left atrial spontaneous echo contrast and/or thrombosis is rare in patients with grade 3 or 4 in native mitral valve regurgitation and explains the low incidence of systemic embolism in these cases.

[Paradoxical embolisms after pulmonary embolism. 6 cases]. / Embolies paradoxales au décours d'une embolie pulmonaire. 6 observations.

Among a series of 6 patients who had paradoxical emboli after pulmonary embolus, thrombus was encrusted in the foramen ovale in 2 while contrast echocardiography showed a free foramen ovale in the 4 others. Surgical embolectomy was performed in 1 of the patients with a thrombus in the foramen ovale. This patient died in the post-operative period and the second patient died suddenly before the indication for surgery had been established. The 4 other patients were treated medically with anticoagulant therapy. After a follow-up of 37, 33, 32 and 3 months respectively none of these patients has developed recurrent emboli. The association of a thromboembolic disease and a systemic ischaemic event should strongly suggest the diagnosis of paradoxical embolus. Echocardiography is required to determine whether the foramen ovale is free or harbours a thrombus.

[Apical hypertrophic myocardiopathy with mid-ventricular obstruction and apical necrosis]. / Myocardiopathie hypertrophique apicale avec obstruction médio-ventriculaire et nécrose apicale.

In a 41-year old man hospitalized for investigation of a systolic ejection murmur, echocardiography revealed an apical (17 mm) and, chiefly, a mid ventricular (38 mm) myocardial hypertrophy resulting in a true stricture at that level. During systole the mid ventricular area became obstructed, dividing the left ventricule into an apical akinetic chamber and a proximal hyperkinetic chamber. Left ventriculography confirmed this abnormality and catheterization showed a left intraventricular pressure gradient of 60 mmHg. Although left coronary arteriography proved normal, myocardial radionuclide scanning at exercise displayed apical necrosis which resulted in a peculiar haemodynamic behaviour well demonstrated by doppler ultrasound. The apex of the left ventricle was filled in two stages: first, during atrial contraction, giving at doppler (mid ventricular sample) a positive flow with a speed of 1m/sec during 120 ms; then, during the isovolumetric period, giving a positive flow with a speed of 1m/sec during 60 ms. The apex drained during systole and protodiastole, giving a negative mid ventricular obstruction flow with a speed of 4 m/sec with protosystolic and mesodiastolic reinforcement.

Model calculations of the interaction of two parallel antiaromatic 4n pi-electron systems.

The nature of the interaction between decks of a pentalene dimer and an s-indacene dimer has been studied by semi-empirical MNDO/1 and MINDO/3 calculations for distances between decks of from 5 A to 2 A. In contradiction to qualitative predictions from a frontier orbital analysis, it is found that the 4n-4n pi-electron interaction between decks for such dimers is destabilizing for distances exceeding about 2.5 A.

[Results of valve replacement with cloth-covered Starr-Edwards ball valve prosthesis (author's transl)]. / Résultat des remplacements valvulaires par prothèse de Starr-Edwards à cage habillée et bille métallique.

Cloth-covered Starr-Edwards prosthesis, was used to replace either the aortic valve (54 cases) or the mitral valve (71 cases), between 1968 and 1978, in an attempt to reduce the incidence of thrombo-embolic complications. Comparative studies using a silastene ball prosthesis during the same period showed that after aortic replacement, the mortality rate during the first month (12 p. cent), late deaths (actuarial survival curves), and most complications (including thrombo-embolin) were not significantly different in the two groups. Hemolysis is significantly greater after the two groups. Hemolysis is significantly greater after replacement with the metallic ball prosthesis; in one patient there was a mechanical change in the material. After mitral replacement, hospital mortality rates (6 p. cent) and the survival curves, after silastene or cloth-covered prostheses, did not differ significantly. Cloth covered mitral valve cause a significantly higher, but compensated rate of hemolysis, a metallic noise heard by 22 p. cent of the patients, and a significant reduction (about 1/5) in the incidence of thromboembolic complications.

[Late thrombosis of mitral valve prosthesis in 27 cases]. / Thromboses tardives sur prothèses mitrales a propos de 27 observations.

Twenty seven cases of late thrombosis of ball and floating or tilting disc prostheses were studied. All patients were on anticoagulant therapy which appeared to be well adapted in 33% patients. Signs suggestive of thrombosis were inconsistant and the diagnosis was made on the association of severl of the following features: -- systemic embolism (44%); -- radiographic signs of left ventricular failure (51%); -- absence of opening click, variable A2 -- opening click intervals, apparition or aggravation of a systolic regurgitant murmur or a distolic murmur suggestive of obstruction on the phonocardiogramme; -- delayed opening of the mobile component or the presence of abnormal echos between the ball and anterior cage echo on the echocardiogramme; -- a gradient of over 12 mmHg across the prosthesis. An isolated episode of systemic embolism when the rest of the work-up is negative may be managed by the addition of a platelet antiaggregant and reinforcement of the anticoagulant therapy; further investigaton is advisable in the face of progressive symptoms. Fibrinolytic treatment and/or surgery is justified when systemic emboli recur or if the work-up is positive.

[Valve replacement and aorto-coronary bypass]. / Remplacement valvulaire avec pontage aorto-coronaire.

Combined surgery on the valves and on the coronary arteries by bypass grafts has been carried out on 27 consecutive patients (1970 to 1976) and involved 18 aortic valve replacements, 8 mitral valve replacements, and one double mitro-aortic replacement; the mean duration of extra-corporeal circulation (145 mn) was significantly higher than that for valve replacements alone carried out during the same period (p less than 0.01). The five deaths occurring in hospital (18.5%) all occurred in the aortic valve group, and were amongst the first 15 cases operated on (1970 to 1974). The 4 post-mortem studies carried out showed similar findings, namely myocardial infarction and significant coronary lesions which had not been bypassed. Two secondary deaths due to infective complications occurred in the first six months. The 17 patients who were followed up after surgery and had a mean follow-up period of 24 months, were all substantially improved by comparison with their pre-operative state, despite certain complications affecting either the valves (1 requiring re-operation) or the coronary arteries (3 infarcts). The indications for coronary arteriography, which are related to the indications for surgery, are being enlarged so that they will include the majority of patients operated on excluding those of more than 65 to 70 years of age and also those aged less than 40 years who have no risk factors for atherosclerosis and no clinical or electrocardiographic signs suggesting a coronary lesion. A study of the operative risk factors has shown the importance of unsuspected coronary lesions, and would appear to indicate correction of all valvular and coronary lesions seen at the time of operation.

[Prospective etiologic survey on apparently primary nonobstructive myocardiopathies in adults. 57 cases, excluding ischemic cardiopathies]. / Enkquête étiologique prospective sur les myocardiopathies non obstructives présumées primitives de l'adulte. 57 observations, cardiopathies ischémiques exclues.

A prospective study into the aetiology of presumed primary non-obstructive cardiomyopathy was carried out in 57 patients who had no lesions of the trunk of the coronary artery; one case of haemochromatosis and one of amyloidosis were found. Excluding these two cases of cardiomyopathy which were in fact secondary, most of the others were associated with manifestations or with complications of myocardial diseases (two pulmonary emboli and one case of jaundice) or pathology associated with it. Investigation into possible infection, biochemical abnormalities and dietary indiscretion (alcohol, colza oil), were unfruitful. Electromyographic changes of the "myositic" type were very common. The bicycle ergometry test was often interrupted through fatiguing of the peripheral muscles. These findings suggest that the muscular abnormalities may not be limited to the heart. The cost of an enquiry of this type has been investigated.

[Changes in the aortic prosthesis surgical risk]. / Evolution du risque opératoire des prothèses aortiques.

Between May 1963 and December 1976, 889 patients underwent single valve aortic replacement by prosthesis. Hospital (30 day) mortality fell, with an exponential decrease (r = 0.94, p less than 0.01) to 4 per cent in 1976. Early risk factors are studied, taking into account the changes affecting them respectively over the time period considered. The average age of the patients increased but did not significantly affect operative mortality. Cardio-thoracic ratio, sex and the duration of extracorporeal circulation had little or no prognostic value. Only classification in class IV of the N.Y.H.A. and the type of valvular disease (severe incompetence) were of clearly pejorative significance. Most deaths occurred early in a context of signs of poor cardiac output, severe disturbances of ventricular rhythym, visceral (digestive) syndromes and/or thrombotic complications. They were characterised at autopsy by sub-endocardial haemorrhagic lesions. The prevalence of these lesions and that of early deaths appeared to decrease with techniques for myocardial protection during the operation.

[Re-operations on patients with ball valve prostheses]. / Réintervention sur prothèses valvulaires à bille. 66 observations.

Out of 989 cases with a ball-valve prosthesis, 66 have been reoperated (6.7%). 2.9% of the cases reviewed annually have thus been reoperated. The main indications for reoperation were displacement (75.5%), malfunction (10.5%) which was related to a failure of the material of the prosthesis or to the deposition of fibrinous plaques, and associated lesions (14%) which were valvular, coronary or myocardial. There were multiple complications in 36 patients. The operative mortality was 31.8% (21.7% over the last two years). On statistical analysis, the significant risk factors were a previous history of bacterial endocarditis, grouping in Class IV of the NYHA classification, enlargement of the QRS complex (0.12 s), urgency of reoperation, and prolonged extracorporeal circulation (2 hours). The rapid fall in survival time was due in part to late deaths (16 patients). By way of contrast, the clinical result was satisfactory in 71% of the survivors. Analysis of the causes of failures has lead to a search for ways of preventing the necessity for reoperation.