Determination of optimal timing of serial in-utero transfusions in red-cell alloimmunization.

OBJECTIVES: To assess the performance of middle cerebral artery peak systolic velocity (MCA-PSV) and of the expected daily decrease in fetal hemoglobin in determining the timing of serial in-utero transfusions (IUT) in red-cell alloimmunization. METHODS: This was a retrospective study of a continuous series of suspected anemic fetuses undergoing IUT between June 2003 and December 2012. Doppler measurement of MCA-PSV and pre- and post-transfusion hemoglobin levels were recorded at the time of the first, second and third IUT. Receiver-operating characteristics (ROC) curves and negative and positive predictive values of MCA-PSV in the prediction of severe fetal anemia were calculated. The daily decrease of fetal hemoglobin (Hb) between IUTs was calculated. Regression analysis was used to assess the correlation between pretransfusion fetal hemoglobin and MCA-PSV, and between observed and expected (by projection of daily decreases) pretransfusion fetal hemoglobin levels. RESULTS: One hundred and eleven fetuses required an IUT, of which 96 and 67 received a second and third IUT, respectively. The area under the ROC curve for MCA-PSV in the prediction of severe fetal anemia was not different for each rank of transfusion. The positive predictive value of MCA-PSV decreased from 75.3% at the first IUT, to 46.7% and 48.8% at the second and third IUTs, respectively, while the negative predictive value for a 1.5-MoM threshold remained high (88.9% at the second and 91.7% at the third IUT). The mean daily decrease in hemoglobin following each transfusion was 0.45, 0.35 and 0.32 g/dL, respectively. There was a persistent linear correlation between fetal hemoglobin and MCA-PSV and between observed and expected fetal hemoglobin levels. CONCLUSIONS: Both MCA-PSV and projection of daily decrease in hemoglobin are reliable means of diagnosing fetal anemia following previous IUTs. The high negative predictive value of MCA-PSV could allow subsequent IUTs to be postponed in selected cases.

Parathyroidectomy in the Lyon hypertensive rat: cardiovascular reactivity and aortic responsiveness.

We have studied the effect of parathyroidectomy on the systolic blood pressure, cardiovascular reactivity and the contractile response of isolated aorta to norepinephrine in the genetically hypertensive Lyon rat strain (LH), parathyroidectomized hypertensive Lyon rats (LH-PTX) and parathyroidectomized hypertensive Lyon rats given a Ca-enriched diet to re-establish normocalcemia (LH-PTX + Ca). Parathyroidectomy significantly lessened (-20%) the development of elevated blood pressure. In the LH-PTX + Ca, the blood pressure was lower than that of LH controls but was higher than that of LH-PTX. At 23 weeks, in vivo responsiveness to norepinephrine and angiotensin II was significantly lower in the LH-PTX and only slightly decreased in the LH-PTX + Ca. In contrast, at the same age, the in vitro contractile response of isolated aortas to norepinephrine was significantly higher in the LH-PTX compared with other groups. Interestingly, without endothelium, this difference disappeared. In conclusion, parathyroidectomy lessened the blood pressure elevation in the Lyon model of hypertensive rats via mechanisms that are partly independent of serum calcium levels.

Relation between calcium and cardiovascular reactivity in mineralocorticoid-induced hypertension in the rat.

1 Previous work has shown that parathyroidectomy (PTX) decreases cardiovascular reactivity to noradrenaline in Sprague-Dawley rats with mineralocorticoid-induced (D) hypertension. 2. In order to explain this diminution of cardiovascular reactivity, we studied in vivo the influence of serum calcium levels on the cardiac and vascular response to noradrenaline (500 ng/kg). We used rats with or without parathyroids but fed a standard or a high-calcium (+Ca) diet that re-established a serum calcium level of about 100 mg/l. Work was performed in vagotomized, anaesthetized rats after ganglionic blockage with pentolinium and atropine sulphate. 3 Cardiac output was unchanged in all the experimental groups after 11 weeks of mineralocorticoid treatment. The enhancing effect of noradrenaline was not modified. 4. Since a serum calcium level of about 100 mg/l was sufficient to re-establish vascular reactivity to exogenous noradrenaline in the PTX-D rats, parathyroid hormone was not necessary. 5 The total and lanthanum-resistant calcium fractions of the walls of the aorta were reduced in the PTX-D rats. When serum calcium levels were re-established at about 100 mg/l, there was no difference between PTX-D and D rats. 6 It is postulated that the decreased storage of calcium in vascular smooth muscle cells of PTX-D rats depresses the vascular effect of noradrenaline.

Parathyroid hormone acute vascular effect is mediated by decreased Ca2+ uptake and enhanced cAMP level.

Cardiovascular effects of parathyroid hormone (PTH) have been recently described. Pharmacological doses of PTH both reduce arterial pressure and increase blood flow of vascular beds. Two possible cellular mechanisms were investigated: (a) transmembrane Ca2+ fluxes and (b) cyclic AMP response in vascular smooth muscle. In vivo, results in the rat show that injection of synthetic bovine 1-34 fragment of PTH (bPTH-(1-34] produced a rapid (1-2 min) but transient (5-16 min) hypotensive effect which was dose-related (0.4-4 nmol.kg-1). In the in vitro studies on isolated rat aorta, bPTH-(1-34) partially inhibited noradrenaline (NA)-induced contractions by decreasing the sustained tonic component dependent on extracellular Ca2+. bPTH-(1-34) also produced relaxation of aorta preconstricted with NA or prostaglandin F2 alpha. Measurements of the lanthanum-resistant Ca2+ pool using 45Ca2+ showed that bPTH-(1-34) decreased basal Ca2+ uptake and partially inhibited Ca2+ uptake stimulated by NA or K+-depolarizing solution in a concentration-dependent fashion. In addition, bPTH-(1-34) caused a concentration-related increase in cyclic AMP in rat isolated aortic tissues. Hypotensive and vasorelaxing effects of bPTH-(1-34) thus appear to be mediated by a decrease in the amount of Ca2+ available for contraction and by an increase in cyclic AMP response in vascular smooth muscle cells.

Dietary calcium, vascular reactivity, and genetic hypertension in the Lyon rat strain.

In order to examine the relationship existing between dietary calcium and the development of hypertension, we developed a long-term study in the Lyon hypertensive rat strain (LH) and two control strains, the Lyon normotensive (LN) and low blood pressure rats (LL) given enriched (HCa, 2.5%), deprived (LCa, 0.03%) and normal (NCa, 0.6%) calcium diets. Evolution of body weight, systolic blood pressure (BP), plasma calcium and magnesium was monitored from 4 to 23 weeks of age. Total cardiovascular reactivity and contractile response of isolated aorta to norepinephrine were measured at 23 weeks of age. LH rats on HCa diet failed to develop hypertension (BP less than 150 mm Hg) whereas LH rats on LCa diet exhibited higher blood pressure levels than their controls fed the NCa diet. Moreover, in LN rats HCa diet slightly decreased BP whereas LCa had no effect. In the LL rats, on the contrary, only LCa diet slightly increased BP. In vivo responsiveness to NE was significantly higher in LH compared to LL and LN rats fed a NCa diet. HCa and LCa diets both induced a significant decrease in this response in LH rats. HCa diet increased the response in LN rats but decreased it in LL. In contrast, at the same age, the in vitro contractile response of isolated aorta to NE was significantly decreased in LH compared to LN and LL rats receiving NCa diet. Moreover in LH and LN rats on HCa diet the contractile response was markedly increased but no significant difference was observed with LCa diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Ions, parathyroids, and genetic hypertension.

Several reports suggested an involvement of parathyroid function in blood pressure regulation in animals and humans: hyperparathyroid subjects frequently display an elevated systolic blood pressure and young mild hypertensive patients show enhanced serum PTH levels. Moreover, removal of parathyroid glands (PTX) in young rats attenuates and delays the development of mineralocorticoid and genetic hypertension. In addition, in vivo cardiovascular reactivity to norepinephrine in PTX rats from both spontaneously the hypertensive rat (SHR) and Lyon hypertensive rat (LH) strains is decreased, as is calcium content in aortic and heart fragments. Moreover, parathyroid grafts from SHR, stroke-prone SHR (SHR-SP), LH, or Milan hypertensive rats (MHS) into previously parathyroidectomized normotensive recipient rats have been shown to induce an increase in blood pressure. Recently, in essential hypertensive patients and in SHR, a circulating hypertensive factor has also been described. Produced by the PTX in SHR, this factor is inversely related to the amount of dietary calcium. It appears, therefore, that the PTX plays a major role in experimental and probably also in human hypertension.

[Retrospective study of exchange transfusion for newborn infants with reconstituted blood. Review of 60 exchanges]. / Etude rétrospective de l'exsanguinotransfusion du nouveau-né au moyen de sang reconstitué. Bilan de 60 échanges.

PURPOSE: The necessity of saving blood products has established the practice of exchange transfusion (ET) with reconstituted blood in newborns. The aim of this retrospective study was to evaluate the indications and the practice of this technique at the Perinatal Hemobiology Centre (Paris, France). METHODS: The records of intervention allowed us to review the etiologic categories for neonates having undergone exchange transfusion with reconstituted blood, the dosages used (bilirubin, hemoglobin), and the other main parameters of ET. RESULTS: Sixty ETs were performed in 48 newborns between the 1st July 1996 and the 1st July 1998. Twenty-seven with Rh hemolytic disease had 39 ETs (19 for hyperbilirubinemia, 12 for anemia, and eight for both), whereas ten out of 12 repeated ETs were indicated for hyperbilirubinemia (six of these cases were in newborns weighing > or = 2500 g and after a volume exchange < or = 1 blood mass [range 0.72-1.0] at the last ET). Twenty-one cases showed other diseases: six of them had anemia, nine had hyperbilirubinemia, and seven showed disseminated coagulopathy. The tolerance of ET was poor in 24% infants in this group. CONCLUSIONS: The volume of 1.3 blood mass for ET is sufficient for the majority of cases with hyperbilirubinemia, allowing transfusional savings in comparison with the previous recommendation of two blood volumes. Exact labeling of the content of units of packed red cells and plasma is essential to fulfill the volume and hematocrit requirements in every case.

[Genetic hypertension in the rat is partially dependent of parathyroid glands. Results of a crossed transplantation trial]. / L'hypertension artérielle génétique chez le rat est partiellement dépendante des glandes parathyroïdes. Résultats d'une expérience de transplantation croisée.

The parathyroid hypertensive factor (PHF) is present in the plasma of SHR rats. The authors of this study set out to determine whether this factor was also present in the Lyon (LH male and female) and Milan (MHS male) hypertensive rats. Five week old normotensive rats (LN and MNS) were transplanted with the parathyroid glands of LH and MHS rats immediately after parathyroidectomy (PTX). Plasma calcium fell rapidly after PTX but returned to physiological levels, confirming the functional activity of the graft. Systolic blood pressures of transplanted rats were significantly higher than normotensive LN and MNS controls. These results confirm the role of the parathyroid glands in the genesis of hypertension in Lyon and Milan male and female rats. They suggest that PHF may be implicated in the hypertensive mechanisms of these two models of genetic hypertension.

[Chronic and acute effect of cycletanine in NO-dependent hypertensive pregnant rats]. / Effet chronique et aigu du ciclétanine chez la rate gestante en hypertension NO-dépendante.

Decreased response to vasopressor agents characterizes pregnancy. Endothelium-derived relaxing factors and vasodilating prostaglandins play an important role in the vascular tone during pregnancy. Since inhibition of nitric oxide (NO) biosynthesis induced by NO2-arginine enriched diet produced hypertension we measured in vivo cardiovascular responses to PGF2 alpha, L-arginine (L-arg) and cicletanine (Cic, IPSEN, France) which enhances PGI2 production. From day 13 to day 20 of gestation 4 groups of female Wistar rats were fed NO2-arg (31 mg/kg/d), NO2-arg+Cic (10 mg/kg/d), Cic enriched or control diet (C). Mean arterial pressure (MAP) was measured via a carotid catheter in anesthetized rats. Injection of PGF2 alpha (50 micrograms/kg) in jugular vein significantly increased MAP in the NO2-arg group versus, NO2-arg+Cic, Cic and C group (+23.5 +/- 3.3 vs +15.7 +/- 2.2, +15.8 +/- 2.2 and +17 +/- 1.85 mmHg; p < 0.01). Injection of L-arg (100 mg/kg) or Cic (1 mg/kg) 5 min before PGF2 alpha produced no modification in MAP in C and Cic group. Likewise in NO2-arg group injection of L-arg or Cic produced a diminished pressor response to PGF2 alpha (+23.5 +/- 3.3 vs -17.5 +/- 1.7 mmHg; p < 0.05 and +15.2 +/- 2.4 mmHg; p < 0.01 respectively). In NO2-arg+Cic group, only injection of Cic induced a diminished pressor response to PGF2 alpha which is more important without L-arg (+15.7 +/- 2.2 vs +9.1 +/- 1.3 mmHg; p < 0.001) or with L-arg (+13.6 +/- 1.5 vs +9.1 +/- 1.3 mmHg; p < 0.01). Cicletanine also significantly diminished the proteinuria in the NO2-arg+Cic group versus NO2-arg group (13.9 +/- 4.36 vs 63.4 +/- 21.6 mmHg; p < 0.01). IN CONCLUSION, chronic NO synthesis inhibition enhanced blood pressure and pressor responses to PGF2 alpha during pregnancy in rats. Chronic administration of cicletanine in Wistar pregnant rats decreases the response to vasopressor agents like PGF2 alpha. Moreover acute and chronic administration of cicletanine blunted the pressor effect, which was lower than in normal gestation.

[Infectious endocarditis caused by Streptococcus bovis and alcoholic cirrhosis complicated by hepatoma]. / Endocardite infectieuse à streptocoque bovis et cirrhose éthylique compliquée d'hépatome.

The case is reported of a 66-year old man who developed Streptococcus bovis endocarditis on a fairly loose aortic stenosis and who also presented with alcoholic cirrhosis complicated by an ultimately lethal hepatoma. On this occasion, comments are made on the following points: -Str. bovis is increasingly responsible for bacterial endocarditis. This micro-organism is now rapidly and reliably identified. -Str. bovis endocarditis has some clinical features of its own. -Patients in whom the usual portals of entry of bacterial infection (i.e. benign or malignant tumours of the colon or rectum) cannot be identified should be investigated systematically for hepatic cirrhosis. -Drug sterilization of the gut is useful to prevent bacteremia of intestinal origin in cirrhotic patients.

[Dietary calcium and arterial hypertension in the rat]. / Calcium alimentaire et hypertension artérielle chez le rat.

The effect of diets modified with respect to their calcium content was studied in three models of hypertensive rats: mineralocorticoid hypertension, DOCA + saline rats and genetic hypertension, SHR and LH rats. Normocalcemic control diet, was equilibrated in vitamins and contained 0.6 p. 100 Ca, 0.24 p. 100 Na and 0.6 p. 100 K. Low calcium diet with only 0.03 p. 100 Ca was studied in the SHR from 5 to 10 weeks of age. Calcium enriched diets contained 1.3, 1.2 and 2.5 p. 100 calcium respectively for DOCA (6 to 16 weeks), SHR (5 to 44 weeks) and LH (female rats, 4 to 22 weeks). In the SHR low calcium diet enhanced hypertension. At the opposite in the three models, calcium enriched diet lessened hypertension. The effect appeared within 2 weeks and was long lasting. These results clearly establish that in young hypertensive rat a low calcium diet enhances the development of hypertension and confirm earlier works with calcium enriched diets. Experimental and clinical data from other groups leads us to emphasize the importance of alimentary calcium in the hypertensive pathology.

[Hypotensive effect of endothelin-1 in a rat model of pre-eclampsia]. / Effet hypotenseur de l'endothéline-1 (ET-1) chez la rate gestante en hypertension NO-prive.

Hypertensive pregnant rats with inhibition of NO synthase are frequently considered as model of pre-eclampsia with proteinuria, hypertension and elevated endothelin (ET-1) blood levels. We describe here the cardiovascular in vivo effects of ET-1 in this rat model since ET-1 and NO are both important vasoactive mediators in uteroplacental circulation. From day 13 of gestation 2 groups of Wistar female rats were fed control (C) or nitroarginine enriched diet (0.063%, Treated: T). On gestational day 20 mean arterial pressure (MAP, mmHg) was measured via a carotid catheter in pentobarbital (60 mg/kg) anesthetized rats. After chronic NO synthase inhibition hypertension develops; MAP on day 20: 158 +/- 2.2 in T and 113 +/- 2.2 in C, p < 0.001. ET-1 bolus injection (0.1 nmol/kg) is rapidly followed by a decrease in blood pressure significantly more important in T: -46 +/- 5.1 than in C: -30 +/- 2.2. In vivo depressor effect is blocked by the specific antagonist BQ-788. After inhibition of cycloxygenase with acetylsalicylic acid (27 mumol/kg, 30 min before) the hypotension is not modified. Since NO and PGI2 productions are not expected in our conditions, vasodepressor effect can be explained by an endothelial hyperpolarazing factor (EDHF). In conclusion in vivo ET-1 hypotensive effects in pregnant rats are mediated by ETB receptors and more pronounced in hypertensive NO-deprived animals.

[Angiographic morphology of the coronary arteries after a recent myocardial infarction treated by intravenous thrombolysis]. / Morphologie angiographique des artères coronaires après un infarctus myocardique récent traité par thrombolyse intraveineuse.

Thirty patients (26 men, 4 women) aged from 32 to 73 years (mean 54 years) who developed anterior (14 cases) or posterior (16 cases) myocardial infarction received intravenous streptokinase in doses of 1,500,000 units 2 to 10 hours (mean 4 hours) after the onset of infarction. Coronary angiography, performed 18.6 days on average after thrombolysis, showed a distinct predominance of asymmetrical stenosis with irregular walls and a narrow neck (10 cases, 33 p. 100) or of complete occlusion (12 cases, 40 p. 100) in the artery responsible for the infarction. Complete occlusion probably was the ultimate stage of stenosis. In contrast, the various angiographic images observed in arteries unrelated to the infarction were evenly distributed. The radiological morphology of coronary arterial lesions after a recent infarction is suggestive of ruptured atheromatous plaque, sometimes complicated by thrombosis in situ. Identical images are seen in unstable angina. These findings indicate that one single therapeutic approach should be applied to the most severe types of coronary disease due to atherosclerosis.

[Infectious endocarditis induced by Actinobacillus actinomycetemcomitans. 8 new cases]. / Endocardite infectieuse à Actinobacillus actinomycetemcomitans. Huit nouvelles observations.

A commensal organism of the buccal cavity, Actinobacillus actinomycetemcomitans (AAC) has been responsible for at least four new cases of infectious endocarditis by year in France. This retrospective study was based on 90 new cases of infectious endocarditis by AAC, including 8 personal observations. One third of patients had no known cardiac disease before their infectious endocarditis, the portal of entry of which was usually dental. In cases of suspected infectious endocarditis, rapid and severe weight loss (43% of cases) and, less commonly, anicteric cholestasis (8%) should alert the physician for the possible pathological role of AAC. The echocardiographic appearances are non-specific. The diagnosis is confirmed on blood cultures but the organism grows slowly in CO2 enriched atmosphere. Initially, the course of the disease was favourable in one third of patients but, in two thirds of cases, complications were observed almost renal (26%), cardiac (24%) and neurological (18%). Two thirds of patients were cured by the time they were discharged whereas the remainder had sequellae, mainly valvular and neurological. The hospital mortality was 9%; late mortality was 6%. Therefore, the prognosis of AAC endocarditis, seems to be better than that of other bacteriological forms. A combination of cephalosporin and aminoside, or even a simple third generation cephalosporin antibiotic therapy for at least 4 weeks are usually effective. The complementary surgical indications are the same as for other forms of infectious endocarditis. Prophylaxis depends on strict prophylactic amoxicillin therapy for all cardiac patients at risk of infectious endocarditis before dental treatment and on good bucco-dental hygiene.

[CRST syndrome. Ultrastructural and physico-chemical studies of calcifications (author's transl)]. / Syndrome CRST. Etude ultrastructurale et physico-chimique des calcifications.

The subcutaneous calcifications in a case of CRST syndrome were studied by electron microscopy and by several physico-chemical tests in order to establish their structure and development. Samples of powder, obtained by crushing and homogenisation of the deposits, were subjected to the following analyses: - radiocrystallography by X-ray of the raw and heated material - infra-red spectroscopy before and after heating - quantitative chemical analysis and differential thermal micro-analysis. Connective tissue fibres seemed to play an important part in the development of the calcifications. The initial deposits of calcium first appeared in the central part of elastic fibres whose general morphology remained nevertheless undisturbed. In the older deposits disorganised elastic (and possibly collagen) fibres and areas of bone formation were found. Evidence of an inflammatory reaction was always minimal or nil. There was considerable variation in the calibre of collagen fibres in the non-calcified zones, the smaller fibres predominating. These appearances, sometimes noted in scleroderma, seem to be associated with increased collagen synthesis. X-ray diffraction and infra-red spectroscopy studies show that the deposits consist essentially of type B hydroxyapatite carbonate, confirmed by differential thermic analysis. On electron microscopy the calcifications were shown to comprise straight, needle-like crystals, 100-600 nm in length and 30-100 nm broad, characteristic of the apatites. Very occasionally, target-pattern deposits conforming to whitlockite were encountered. Chemical analysis revealed a high proportion of calcium with a Ca/P ratio greater than 1-666 as is typical of synthetic hydroxyapatite carbonates. The deposits also contained up to 20% by weight of organic material.

[Use of vicryl mesh for reinforcing the pancreatic stump in pancreatojejunostomy]. / Utilisation d'une bandelette de vicryl de renforcement dans l'anastomose pancréatojéjunale sur pancréas sain.

After cephalic pancreaticoduodenectomy, the author suggests wrapping of the pancreatic stump with a vicryl strip on which the pancreatojejunal anastomosis can be fixed in order to prevent the risk of fistula.

[An overlooked electrocardiographic sign of acute embolic cor pulmonale: elevation of the ST segment in right precordial leads]. / Un signe électrocardiographique "oublié" du coeur pulmonaire aigu embolique: le décalage supérieur du segment ST en dérivations précordiales droites.

Elevation of the ST segment in the right precordial leads may be associated with electrocardiographic signs of acute cor pulmonale. This sign, which we have observed in 77 cases of moderate to severe pulmonary embolism (greater than 1.3 per cent of cases), is a very early but transient sign of usually moderate to severe pulmonary embolism. In the presence of this sign, the diagnosis of pulmonary embolism with acute cor pulmonale should be proposed at the same time as more common aetiologies such as coronary insufficiency and pericardial disease.

[Value of echocardiography in aged patients with presumed idiopathic auricular fibrillation]. / Intérêt de l'échocardiographie chez les patients âgés atteints de fibrillation auriculaire présumée idiopathique.

Thirty seven patients (mean age = 80.2 years with extremes from 66 to 98 years), presenting atrial fibrillation (AF), presumably idiopathic (non known heart disease, completely normal cardiac auscultation, good quality chest X-ray and electrocardiogram, no laboratory test anomaly), and paroxystic (n = 7: 19 p. cent) or permanent (n = 30: 81 p. cent), were given an electrocardiogram TM and bidimensional. In only 9 of them (24.3 p. cent), this examination is completely normal. Three other patients (8.1 p. cent) present an isolated dilatation of the left atrium. The 25 remaining patients present various cardiopericardic anomalies: valvular pathologies (n = 2: 59.4 p. cent): mitral (n = 15: 40.5 p. cent) more often than aortic (n = 7: 18.9 p. cent); myocardiopathies (n = 8: 21.6 p. cent), hypertrophic (n = 2), dilated (n = 4) or hypertrophic and dilated (n = 2); moderate pericardial effusion (n = 1: 2.7 p. cent). The mean left and right ventricular diameters, measured in TM mode, are normal as well as the mean contractility indexes (percentage of shortening of the small axis, stroke volume) and the mean filling index (mitral gradient EF) of the LV. Overall, the transverse diameter of the LA is moderately increased (41.9 +/- 9.7 mm); it is not significantly different from the AF, either paroxystic (41.5 +/- 4.9 mm) or permanent (42 +/- 9.93 mm) and whether it is (40.5 +/- 9.9 mm =) or not (42.5 +/- 8.8 mm) complicated by a systemic embolism, especially cerebral. Therefore, the sonocardiogram demonstrates a latent cardiopathy in two-thirds of the patients over 65 presenting a presumably idiopathic AF.(ABSTRACT TRUNCATED AT 250 WORDS)

[Coronary insufficiency caused by atherosclerosis. Current pathogenic concepts, clinical, angio-anatomic correlations and therapeutic deductions]. / L'insuffisance coronarienne par athérosclérose. Conceptions pathogéniques actuelles, corrélations angio-anatomiques, cliniques et déductions thérapeutiques.

The multiplicity of clinical expressions of coronary artery failure results from the interaction between three processes which varies from one patient to another and from one time to another in a given patient. The three processes involved are: atheromatous coronary stenosis, arterial spasm and the development of a fibrino-thrombocytic thrombus. In stable angina pectoris, atheromatous narrowing, with smooth, regular outlines, no endothelial injury and little likelihood of complication by thrombosis predominates. In contrast, labile angina and myocardial infarction give rise to the same lesions: usually irregular stenoses, with a narrow neck and irregular outline. They correspond histologically to the rupture of an atheroma plaque, frequently complicated by the appearance in situ of a clot. In the authors' experience, complete arterial occlusion ensues in three out of four cases. The rate at which aggravation progresses and the variable degree of collateral circulation explains why a whole range of intermediate clinical expressions are possible, ranging from labile angina to sudden death of ischemic origin, and including various forms of infarction (both with and without the Q wave). Healing of these lesions may also be observed, usually resulting in progression of the coronary stenosis and sometimes of modification of left ventricular function of variable duration (myocardial stunning or hibernation). The importance of thrombotic phenomena in triggering the most serious forms of coronary artery failure (labile angina and myocardial infarction) provides a more precise identification of the place of thrombolytic treatment. In addition, it appears that there is no point in emergency revascularization of the ischemic myocardium. However, despite recent clinical progress, coronary artery disease remains a worrying illness which calls for primary prevention measures. Such measures must be undertaken as soon as possible if they are to be effective.

[Effect of tobacco smoking on the incidence of recurrent myocardial infarction. A retrospective study of 208 cases]. / Influence de la consommation de tabac sur la fréquence des récidives d'infarctus myocardique. Etude rétrospective de 208 observations.

Two hundred and eight patients, less than 60 years of age at the time of their first myocardial infarction (MI), which occurred between 1 July 1976 and 30 September 1982, and with a mean recurrence-free follow-up period of 3450 +/- 142 days, were included in a retrospective survey. This concerned the outcome of their coronary artery disease and the persistence of vascular risk factors, notably their tobacco consumption, the extent and forme of which was detailed. This study showed: 1) the mortality rate was 8.8%, 2) 78.4% of the patients smoked before their infarction, 3) 76% of the smokers stopped smoking after this event. The risk of recurrence of infarction was higher amongst smokers. After 5 years, 51.6 +/- 15% of the subjects who had not reduced their daily tobacco consumption had suffered another MI, versus 21.5 +/- 3% of those who had reduced it by 1 to 50%, 16.9 +/- 6% of those who had never smoked and only 10.5 +/- 6% of those who had reduced it by more than 50% or had stopped smoking (p less than 0.02). The relative risk of recurrence of infarction in persistent smokers was 4.4 times that in subjects who had stopped smoking. However, no significant difference was found between the mortality in the various subgroups. In addition to smoking, only two factors were found to significantly promote the onset of a fresh MI: an initial infarction with no Q wave (p = 0.007), and the persistence of spontaneous angina pectoris (p = 0.0009).