Direct Observation of Homogeneous Cavitation in Nanopores.

We report on the evaporation of hexane from porous alumina and silicon membranes. These membranes contain billions of independent nanopores tailored to an ink-bottle shape, where a cavity several tens of nanometers in diameter is separated from the bulk vapor by a constriction. For alumina membranes with narrow enough constrictions, we demonstrate that cavity evaporation proceeds by cavitation. Measurements of the pressure dependence of the cavitation rate follow the predictions of the bulk, homogeneous, classical nucleation theory, definitively establishing the relevance of homogeneous cavitation as an evaporation mechanism in mesoporous materials. Our results imply that porous alumina membranes are a promising new system to study liquids in a deeply metastable state.

[Prognosis of asymptomatic or slightly symptomatic chronic aortic insufficiency. Apropos of 54 patients followed for an average of 36 months]. / Pronostic des insuffisances aortiques chroniques asymptomatiques ou paucisymptomatiques. A propos de 54 patients suivis en moyenne pendant 36 mois.

A series of 54 patients with chronic aortic insufficiency with little (38) or no symptoms (16) were studied. All had severe regurgitation leading to discussion of aortic valve replacement. All patients (44 male and 10 female) underwent clinical, radiological, electrocardiographic, hemodynamic and angiographic investigation with assessment of left ventricular volume by monoplane 30 degrees cineangiography on entry to the study. They were then followed-up for an average of 36 months and the data assessed in a prospective study. At the end of the 36 months period, 4 patients had been lost to follow-up but were still alive, 31 patients were unchanged (Group A) and 19 patients had deteriorated (Group B). The parameters characterising Group B (P less than 0.001) were: corrected cardiac surface area of 1,72 +/- 0,13, a Sokolow index of 60,1 +/- 18,8 mm an ejection fraction of 56.2 +/- 14 % and a left ventricular end diastolic value of 225,3 ml/m2. Therefore, in chronic asymptomatic aortic incompetence, the parameters of cardiac dilatation, cardiac surface area greater than 1,70 and left ventricular end diastolic volume greater than 170 ml/m2, would appear to be good indications for aortic valve replacement. However, the values are nor formal criteria because a discrepancy between symptoms and the volumetric measurements may be observed in some cases, and also large variations in these measurements may be observed in patients in the same functional class.

[Coronary bypass surgery. Results after 5 years : mortality - morbidity]. / La chirurgie de pontage coronarien. Résultats après 5 ans : mortalité - morbidité.

The improvement in the expectation and quality of life of patients undergoing coronary bypass surgery has been studied in the short term but there are relatively few studies with follow-up periods of over five years. The results in 239 patients operated on between 1970 and 1976 are presented. The preoperative data was obtained from a computerised filing system; studies were made at 3 months, at an average of 60 months, and in 78 patients with follow-up exceeding 5 years. Actuarial survival rates were calculated. The operative mortality was 9 patients (3,7%); late mortality was 21 patients (9,2%). Most deaths were due to cardiac causes. The following factors did not appear to be associated with a poor prognosis: sex, the number of cardiovascular risk factors, the number of bypass grafts; however, age and poor left ventricular function as identified by ECG (p less than 0,01), the presence of clinical cardiac failure (p less than 0,001) and by angiography (p less than 0,001) were associated with a poor prognosis. The long-term functional results were interesting: 67% patients followed up to 5 years and 56% patients followed up for over 5 years had no angina. Myocardial infarction occurred in 16,7% of patients at 5 years. Preexisting left ventricular failure which affected the operative and immediate postoperative results was also found secondarily in 9% of patients at 5 years. In the long term, the annual mortality rate seemed to be less in patients with triple vessel disease after myocardial revascularisation. The annual mortality rate of patients with left anterior descending disease alone did not seem to be improved when compared with medically treated patients until after the third year. Once again, the extent of myocardial disease was shown to be the essential prognostic factor whatever the coronary profile of the patient. In this study patients with severe angina or unstable angina who had been treated medically before surgery had the same results as those treated surgically by first intention; this fact is an argument in favour of initial medical management in all forms of angina.

[Prognosis of primary non-obstructive cardiomyopathies]. / Etude pronostique des myocardiopathies primitives non obstructives.

The prognosis of congestive cardiomyopathy was studied in 132 consecutive patients (110 male, 22 female, average age 45 +/- 11 years) in whom a thorough clinical evaluation had excluded a secondary cause. The patients presented with left ventricular failure, a history of systemic embolism, syncope or radiological cardiomegaly. Right (100 p. 100) and left (81 p. 100) heart catheterisation was performed and left ventricular endiastolic volumes (202 +/- 77 ml/m2) and ejection fractions (31 +/- 12 p. 100) calculated from angiography in the 30 degrees right anterior oblique projection. Regional abnormalities of contraction were observed in 32 patients. The average follow up period was 40,4 +/- 23,8 months. At the end of the study 48 patients (37 p. 100) had died and 2 had been lost to follow up. Survival rates were calculated by actuarial methods. Age, sex, the period they had been symptomatic, alcoholic intoxication and the degree of cardiac dilatation were not significant prognostic factors. Patients in Class IV NYHA had the worst prognosis: 63 p. 100 2 year mortality. Atrioventricular conduction defects were observed in 56 patients and were associated with a significantly increased mortality rate (43 p. 100 compared with 23 p. 100, p < 0.001). Atrial fibrillation (32 patients) was a better prognostic factor than the persistence of sinus rhythm; 2 year mortality 11,1 p. 100 compared to 37,6 p. 100 (p < 0.001). Increased left ventricular end diastolic pressures greater than 20 mmHg were related with a mortality of 51,5 p. 100. Also, the patients with a ejection fraction of 30 p. 100 and a 2 year mortality rate of 44 p. 100 compared to 17,5 p. 100 when the ejection fraction was greater than 30 p. 100 (p < 0,001). In conclusion : 1. Regional abnormalities of left ventricular contraction are not rare in primary cardiomyopathy. 2. The prognosis is directly related to the degree of cardiac failure and the extent of left ventricular dysfunction.

[Auricular and left ventricular compliance in acute and chronic mitral insufficiency]. / La compliance auriculaire et ventriculaire gauche dans les insuffisances mitrales aiguës et chroniques.

Left atrial and ventricular compliance has been studied in 25 cases of chronic mitral incompetence (CMI) and 9 cases of acute mitrale incompetence (AMI). Left atrial compliance was evaluated by the ratio between maximal variation in volume and corresponding maximal variation in pressure; it was found to be higher in cases of CMI than in cases of AMI. Left ventricular compliance was evaluated by various indices (Diamond, Mirsky, Gaasch, Laird), and was found to be increased equally in the chronic and acute types. It is possible that an explanation of this increase incompliance is to be found in the rearrangement of myocardial fibres which follows the dilatation. It constitutes a fundamental means of chronic adaptation, and shows that the diastolic elastic properties of the cavities of the atrium and ventricle are as important in the evaluation of mitral incompetence as the properties of systolic contraction.

[Echocardiographic criteria of obstructive cardiomyopathy]. / Critères échocardiographiques de la cardiomyopathie obstructive.

In defining the characteristic abnormalities of obstructive cardiomyopathy (OCM), the echocardiogram appears to offer an excellent method. We have used this technique in 22 adults presenting with this condition, and have compared the results of echocardiography with those taken from 17 normal subjects. All those with OCM had asymmetrical hypertrophy of the septum (meaning hypertrophy of the septum without proportional thickening of the posterior wall of the left ventricle); certain other facts were noted: an undilated left ventricular cavity, good systolic function, and indications of poor diastolic compliance. In addition, from the thickeness of the posterior wall and the movement of the mitral valve complex during systole, it has been possible to draw a distinction between the patients with and those without obstruction while they were all at rest. These results confirm that it is possible to identify obstructive cardiomyopathy and the frequently associated defects of ventricular function by an echocardiographic method.

[Study of survival in angiographically determined ischemic cardiopathies: Apropos of 345 medically treated patients]. / Etude de la survie des cardiopathies ischémiques angiographiquement définies. A propos de 345 patients traités médicalement.

A study of 345 patients with ischaemic heart disease due to coronary arteriosclerosis which had been demonstrated by coronary arteriography, and seen between November 1967 and December 1974, was directed towards finding out what had happened to the patients so that, by an actuarial study of their survival, the prognostic significance of the arteriographic and ventriculographic studies could be determined. The prognostic value of the clinical findings has shown the importance:--of the presence of clinical left ventricular failure;--of the presence of coronary insufficiency with frequent attacks; of the presence of sequelae of infarction as seen on the ECG at rest;--on the length of the symptomatic history before arteriography. The assessment of the prognostic potential of the arteriographic findings has emphasised:--the fundamental importance of diffusion of stenoses and occlusions of several main coronary trunks;--the high risk if the lesion affects the left coronary trunk; the high risk of prognostic significance of lesions on the IVA. The prognostic significance of ventricular lesions as demonstrated on ventriculography in the right anterior oblique incidence has shown the sinister significance of extensive lesions of more than two or three of the seven ventriculographic segments and of lesions with dilatation, whereas very localised static plaques hardly influence the prognosis at all.

[Fatal emboligenic ulcerative endomyocardial fibrosis in filariasis]. / Fibrose endomyocardique ulcérée emboligène mortelle chez un filarien

A man of 54 had been treated over a 15 month period for pulmonary tuberculosis when aged 41, and had lived on the Ivory Coast and then in the Cameroons for 20 years. Eye signs were discovered in January 1971, and these, together with an eosinophilia, pointed to a possible filariasis which was later confirmed by immunofluorescence and the fixation of complement. Three months later, the patient developed congestive cardiac failure. On the 4th day of treatment with Notizine, multiple systemic emboli occurred, leading to death. Autopsy showed endomyocardial fibrosis with multiple ulceration of the left ventricle, the site of the emboli. The aetiology from filariasis and the mechanism of ulceration of the parietal endocarditis are discussed.

[Myocardial infarction in early postoperative complications in operations of myocardial revascularization: incidences, clinical study and mechanisms]. / L'infarctus myocardique dans les suites précoces de la chirurgie de revascularisation myocardique: incidence, étude clinique et mécanismes

A study of the electrocardiograms and enzyme levels after surgery to revascularise the myocardium in a group of 174 consecutive patients has allowed us to demonstrate 19 cases of early postoperative myocardial infarction (EPOMI) (10.9%). 10 of these cases had no clinical features of EPOMI; 9 had clinical signs (collapse of altered systemic pressures, arrhythmias) or haemodynamic disorders (raised left atrial pressure). The EPOMI turned out to be fatal in 3 cases (19%), and to be complicated by left ventricular failure in 6 cases (32%). Post-operative coronary arteriography showed that 8 out of 20 grafts were occluded in 13 patients; ventriculography showed the myocardial damage consequent upon EPOMI in 8 patients out of 12; Autopsy showed graft occlusion in each of the two patients. The means of diagnosis of EPOMI must be electrocardiographic and enzymatic. An attempt has been made to study the causes of EPOMI: aortocoronary bypass hazardous because of poor distal supply (6 cases) or surgical difficulties (6 cases); progression of the atheromatous lesions (3 cases); infarct already inicipient at the time of surgery (1 case). EPOMI is a complication of cardiac surgery which must be recognised; the mechanisms are diverse, and any of the factors which are relevant to the surgical procedure may be a cause.

[Hemodynamic effects of the intravenous form of acebutolol]. / Etude des effets hémodynamiques de l'acébutolol sous forme intraveineuse

Acetubolol was administered intravenously to 11 patients with various heart disorders, without any adverse effects. The bradycardic effect of this compound is slight. It did not change the auriculo-ventricular conduction in 10 patients with sinus rhythm. The effect of acebutolol on myocardial efficacy is slight or absent in controls. At the doses studied, it did not alter systolic arterial pressure. Furthermore, the effect on the myocardial contractility is slight (-10 p.cent, mean). The important point noted is that the drug does not increase the pressure in ventricular filling, the first sign usually of left ventricular insufficiency caused by most other drugs of this pharmacological type.

[Evaluation of the results of myocardial revascularization surgery by exercise tests under electrocardiographic control. Correlations with control coronography].

A myocardial revascularisation procedure was carried out on 68 patients with obstructive atheroma of the coronary arteries associated with severe angina pectoris. In 58 cases a total of 97 vein grafts were used, and in 10 cases the internal mammary artery was anastomosed to the anterior descending artery (using a vein graft in 5 of them). Before operation the patients had selective coronary arteriography, and a maximal exercise test using a bicycle ergometer. Three months postoperatively the patency of the coronary by-pass was checked, and a further exercise test completed. In the exercise test the criteria were the appearance of angina pectoris, improved performance (measured by the duration of exercise, the maximal power, and the heart rate at the end of exercise), and improved ECG findings. These criteria were correlated by the patency of the graft or grafts as noted at arteriography. There was no pain on exercise in 55 patients (81 per cent), the performance improved in 37 (54 per cent), and the ECG findings improved in 50 (72 per cent). At angiography, 34 patients (50 per cent) had a completely patent by-pass (group I), 31 patients (45.5 per cent) had at least one patent graft (group II), and 3 patients (4.4 per cent) had no patent graft (group III). Group I corresponds to 31 good or very good results and to 3 states on non improvement; group II contains 22 good results and 9 states of non improvement; group III corresponds to 3 states of non improvement. Exercise demonstrates the results of myocardial revascularisation surgery; the correlations between these results and those of graft patency justify its use in surveillance of coronary patients who have been operated. Exercise tests show that the best results are obtained in patients with severe functional disturbances and whose ventricular cinetics have remained sufficient.

[Tricuspid incompetence after surgical correction of mitral and mitrio-aortic value diseases. Reasons for its persistence or its recurrence]. / L'insuffisance tricuspidienne après corrections chirurgicales des valvulopathies mitrales et mitro-aortiques. Causes de sa persistance ou de sa récidive

53 patients with mitral or aortic valve disease, observed consecutively, had before operation a marked tricuspid incompetence. 24 had, in the course of corrective mitral or mitral-aortic correction, a surgical attempt at treatment of tricuspid regurgitation; in theremaining 29, tricuspid incompetence was not corrected surgically. The course of the latter group was studied (average follow-up period after operation = 18 months): the operative mortality was 10.3%, and secondary one 20.7%. The functional result was considered good in 55% of the patients, bad (classified III and IV of the NYHA) in 14% of the patients. The postoperative clinical and haemodynamic assessment showed that, in the patients in stages III and IV with persistent ou recurring tricuspid incompetence, the tricuspid lea was, in all cases, secondary to an anomalous function of the left heart (bad function of the prosthesis, persistence of aortic lesions either misvalued or uncorrected). Tricuspid repair in a second stage is unjestified in such cases.