Constitutive activation and oncogenicity are mediated by loss of helical structure at the cytosolic boundary of thrombopoietin receptor mutant dimers

Dimerization of the thrombopoietin receptor (TpoR) is necessary for receptor activation and downstream signaling through activated Janus kinase 2. We have shown previously that different orientations of the transmembrane (TM) helices within a receptor dimer can lead to different signaling outputs. Here we addressed the structural basis of activation for receptor mutations S505N and W515K that induce myeloproliferative neoplasms. We show using in vivo bone marrow reconstitution experiments that ligand-independent activation of TpoR by TM asparagine (Asn) substitutions is proportional to the proximity of the Asn mutation to the intracellular membrane surface. Solid-state NMR experiments on TM peptides indicate a progressive loss of helical structure in the juxtamembrane (JM) R/KWQFP motif with proximity of Asn substitutions to the cytosolic boundary. Mutational studies in the TpoR cytosolic JM region show that loss of the helical structure in the JM motif by itself can induce activation, but only when localized to a maximum of 6 amino acids downstream of W515, the helicity of the remaining region until Box 1 being required for receptor function. The constitutive activation of TpoR mutants S505N and W515K can be inhibited by rotation of TM helices within the TpoR dimer, which also restores helicity around W515. Together these data allow us to develop a general model for activation of TpoR and to explain the critical role of the JM W515 residue in the regulation of the activity of the receptor.

JAK2 ex13InDel drives oncogenic transformation and is associated with chronic eosinophilic leukemia and polycythemia vera

The V617F mutation in the JH2 domain of Janus kinase 2 (JAK2) is an oncogenic driver in several myeloproliferative neoplasms (MPNs), including essential thrombocythemia, myelofibrosis, and polycythemia vera (PV). Other mutations in JAK2 have been identified in MPNs, most notably exon 12 mutations in PV. Here, we describe a novel recurrent mutation characterized by a common 4-amino-acid deletion and variable 1-amino-acid insertion (Leu583-Ala586DelInsSer/Gln/Pro) within the JH2 domain of JAK2. All 4 affected patients had eosinophilia, and both patients with Leu583-Ala586DelInsSer fulfilled diagnostic criteria of both PV and chronic eosinophilic leukemia (CEL). Computational and functional studies revealed that Leu583-Ala586DelInsSer (herein referred to as JAK2ex13InDel) deregulates JAK2 through a mechanism similar to JAK2V617F, activates signal transducer and activator of transcription 5 and extracellular signal-regulated kinase, and transforms parental Ba/F3 cells to growth factor independence. In contrast to JAK2V617F, JAK2ex13InDel does not require an exogenous homodimeric type 1 cytokine receptor to transform Ba/F3 cells and is capable of activating β common chain family cytokine receptor (interleukin-3 receptor [IL-3R], IL-5R, and granulocyte-macrophage colony stimulating factor receptor) signaling in the absence of ligand, with the maximum effect observed for IL-5R, consistent with the clinical phenotype of eosinophilia. Recognizing this new PV/CEL-overlap MPN has significant clinical implications, as both PV and CEL patients are at high risk for thrombosis, and concomitant cytoreduction of red cells, neutrophils, and eosinophils may be required for prevention of thromboembolic events. Targeted next-generation sequencing for genes recurrently mutated in myeloid malignancies in patients with unexplained eosinophilia may reveal additional cases of Leu583-Ala586DelInsSer/Gln/Pro, allowing for complete characterization of this unique MPN.

Impact of hypovitaminosis D and alfacalcidol therapy on survival of hemodialysis patients: results from the French ARNOS study

BACKGROUND

In chronic kidney disease and dialysis patients, vitamin D deficiency is associated with mortality. In some observational studies, calcitriol analogue therapy was associated with a better survival rate in hemodialysis (HD) patients. The aim of this study was to determine the relationship between serum 25-hydroxyvitamin D (25-OHD) levels and alfacalcidol therapy with HD patients' outcomes.

METHODS

We measured baseline 25-OHD levels using a cross-sectional analysis in 648 HD prevalent patients from the regional ARNOS French cohort. A 42-month survival analysis was applied according to serum 25-OHD level and calcitriol analogue therapy.

RESULTS

The prevalence of 25-OHD insufficiency <30 ng/ml was high (73%), with only 22% taking native vitamin D supplementation. A baseline 25-OHD level above the median value (18 ng/ml) was associated with lower all-cause mortality [hazard ratio (HR), 0.73 (0.5-0.96); p = 0.02] after adjustment for age, gender, dialysis vintage, calcemia, phosphatemia, cardiovascular disease, and diabetes. Only in monovariate analysis was low-dose oral alfacalcidol therapy associated with a better survival rate in patients with and without 25-OHD deficiency [HR, 0.7 (0.5-0.92); p = 0.05].

CONCLUSIONS

Our study shows that, among prevalent HD patients, low 25-OHD levels affect mortality. Alfacalcidol therapy, especially in small doses, may provide compensation, but this needs to be further confirmed using prospective controlled studies comparing native and active vitamin D compounds.

Relation of minor cardiac troponin I elevation to late cardiac events after uncomplicated elective successful percutaneous transluminal coronary angioplasty for angina pectoris

There is little information about the relation between mild cardiac troponin I (cTn-I) increase after coronary interventions and late outcome. We therefore focused on the long-term outcome and the clinical, morphologic, and procedural correlates of elevation of cTn-I compared with cardiac troponin T, creatine kinase (CK), CK-MB activity and mass, and myoglobin in 105 patients with successful elective percutaneous transluminal coronary angioplasty (PTCA) for stable or unstable angina. Patients with myocardial infarction and those with unstable angina who had a detectable increase in serum markers before PTCA were excluded. Markers were measured before and after the procedure and for 2 days. Patients were followed up to record recurrent angina, myocardial infarction, cardiac death, repeat PTCA, or elective coronary artery bypass graft surgery. Procedure success was achieved in all cases. Elevation in cTn-I (> or =0.1 microg/L) was observed in 23 of 105 patients (22%) (median peak: 0.25 microg/L); 18% had cardiac troponin T (cTn-T) release (> or = 0.1 microg/L, median peak 0.21); 11.4% CK-MB mass (> or =5 microg/L), and 7.6% myoglobin (> or =90 microg/L) release. Five and 2 patients had elevated CK and CK-MB activity, respectively. Fourteen of 18 patients with cTn-T elevation had a corresponding elevation in cTn-I (kappa 0.68; p = 0.001). Patients positive for cTn-I had more unstable angina (p = 0.042) and heparin before PTCA (p = 0.046), and had longest total time (p = 0.004) and single inflation (p = 0.01). By multivariate logistic regression, predictors of postprocedure cTnI elevation were maximum time of each inflation (odds ratio 9.2; p = 0.0012), type B lesions (odds ratio 6.6; p = 0.013), unstable angina (p = 0.041), and age > or =60 years (p = 0.032). Clinical follow-up was available in 103 patients (98%) (mean 19+/-10 months). Kaplan-Meier survival analysis showed that cTn-I elevation was not an important correlate of cardiac events (p = 0.34, by log-rank analysis). The incidence of recurrent angina, myocardial infarction, cardiac death, and repeat revascularization after 12 months was not different in patients positive or negative for cTn-I. We conclude that cTn-I elevation after successful PTCA is not associated with significantly worse late clinical outcome. Levels of cTn-I allow a much higher diagnostic accuracy in detecting minor myocardial injury after PTCA compared with other markers, but there is no association with periprocedural myocardial cell injury and late outcome when cTn-I and other markers are considered.

[Contribution of doppler echocardiography to the diagnosis of the first attack of acute rheumatic fever]

Since 1944, the Jones criteria for the diagnosis of acute rheumatic fever have been regularly revised to integrate technical and diagnostic innovations. Echographic and Doppler criteria, however, remain unrecognised due to valvular insufficiency in healthy subjects. The aim of this study was to determine the cardiac lesions occurring in acute rheumatic fever and the diagnostic value of Doppler echocardiography. One hundred patients with an average age of 10 years were admitted to hospital because of a first attack of acute rheumatic fever between January 1991 and September 1992. Eighty-six had articular signs, 5 had chorea, but none had cutaneous lesions. Forty-seven murmurs of mitral insufficiency (MI) and eight of aortic insufficiency (AI) were detected; 10 children had signs of cardiac failure. Conduction defects were recorded in 12 cases. Echocardiography showed 7 pericardial effusions; often, the left heart chambers were dilated without alteration of the fractional shortening. The commonest lesions of the mitral valve were thickening of the two leaflets, the reduced mobility of the posterior leaflet, the rigidity of the anterior leaflet and 2 cases of ruptured chordae tendinae. The Doppler mode showed 73 cases of MI, 26 of which were at least moderately severe. These cases of MI were commonly excentric jets behind the posterior leaflet. There were 47 cases of AI, 10 of which were at least moderately severe. If all cases of moderately severe or mild AI and MI are considered as pathological when associated with suggestive morphological valve changes, the number of cases of carditis increased from 50 without the Doppler mode to over 80 with this mode. Doppler echocardiography validated the Jones criteria in 16 children. The authors propose Doppler echocardiography criteria for the validation of carditis.

[Elastic recoil after transluminal coronary angioplasty; implications of clinical and angiographic data]

Secondary elastic recoil after transluminal coronary angioplasty is a constant and immediate phenomenon after successful coronary angioplasty. It was studied by quantitative coronary angiography in 75 consecutive patients undergoing transluminal coronary angioplasty. This procedure was performed on lesions presumed to be responsible for the clinical presentation. The population was divided into 3 groups: stable angina (25 patients), unstable angina (25 patients) and recent post-infarction ischaemic syndromes (25 patients). There were 57 men and 18 women (mean age 59 +/- 11 years) with 31 left anterior descending (LA), 29 right coronary (RC) and 15 left circumflex (Cx) dilatations. The lesions dilated were eccentric in 29 cases and calcified in 37 cases whereas only one thrombus was detected at coronary angiography. The elastic recoil appreciated 10 mn after the last balloon inflation was 0.97 +/- 0.28 mm for the whole population. There was no significant difference between the 3 groups studies (respectively 0.94 +/- 0.24 mm; 0.96 +/- 0.26 mm; 0.99 +/- 0.33 mm). This appeared to be greater than the RC (1.06 +/- 0.30 mm) with respect to the Cx (0.86 +/- 0.23: p < 0.02) or LAD (0.92 +/- 0.25 mm: p < 0.04). Overall, a balloon to vessel diameter ratio > 1 and a lesion length > 10 mm were parameters predicting greater secondary elastic recoil (p < 0.07 and p < 0.001 respectively), whereas the degree of eccentricity only played a role in the post-infarction ischaemic syndromes and calcification only in unstable angina (p < 0.01 and p < 0.001 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

[Permanent cardiac stimulation after aortic valve replacement: incidence, predictive factors and long-term prognosis]

Between January 1981 and June 1992, 382 patients, operated by the same surgical team, underwent aortic valve replacement for pure severe aortic stenosis. This population was divided into 2 groups according to whether or not surgery was complicated by the development of a conduction defect (atrioventricular and/or intraventricular block), necessitating permanent cardiac pacing. The aim of this study was to analyse not only the incidence and predictive factors but also the long-term prognosis of the paced patients (Group II: 22 patients) in comparison with the control group (Group I: 360 patients). The results showed: the incidence of permanent cardiac pacing after this type of surgery remains low (5.7%); the predictive factors of atrioventricular block requiring permanent pacing were: pre-existing conduction defect (p < 0.02), decreased ejection fraction (p < 0.05), calcification extending to the subaortic interventricular septum (p < 0.0001); the long-term prognosis of the patients was good with 5 and 10 year actuarial survival rates of 95.4% and 68.9% respectively, identical to those of the control group.

[Dilated cardiomyopathies in severe cardiac failure in chronic alcoholics: clinical course after complete withdrawal]

We have prospectively evaluated 6 patients admitted for a severe heart failure in alcoholic patients with dilated cardiomyopathy. We concluded that complete abstinence results in a short-term clinical improvement, associated to a significant increase in left ejection fraction.

[Patency of the artery responsible for myocardial infarction: role on ventricular function and long-term outcome]

Out of 3,171 consecutive patients referred for coronary angiography, 240 were selected on the following criteria: recent primary myocardial infarction, single vessel coronary disease, no angioplasty or coronary surgery after the angiography which was performed 20 to 90 days after the onset of myocardial infarction. The patients were divided into 2 groups according to whether the artery responsible for infarction was patent (Group I: 115 patients) or not (Group II: 125 patients). The left ventricular ejection fraction was significantly higher in Group I (58 +/- 10.8%) than in Group II (53.7 +/- 11.3%) and end systolic and end diastolic left ventricular volumes were greater in Group II (51.8 +/- 22 ml/m2 and 88 +/- 22 ml/m2 respectively). Long-term follow-up (56 +/- 25 months in Group I and 61 +/- 26 months in Group II) was possible in 112 patients in Group I and 123 patients in Group II. Of the 7 patients who died in group II, 4 deaths were of cardiac origin; in addition, 2 cases of sustained ventricular tachycardia were observed in this group. None of the 6 deaths observed in Group I was of cardiac origin and there were no cases of ventricular tachycardia (p = 0.05). The functional status was identical in the two groups at the end of the study. These results suggest that the patency of the coronary artery responsible for myocardial infarction at a distance from the acute event is associated with better left ventricular function and a better long term prognosis.

Atrial natriuretic factor release during exercise in patients successively paced in DDD and rate matched ventricular pacing

Dual chamber pacemakers were implanted in nine patients with permanent second or third degree AV block (eight had complete retrograde block). Two identical exercise tests were performed after at least 1 month after implantation. During the first test (T1) the pacemaker was programmed to the DDD mode and heart rates were recorded every 15 to 30 seconds during exercise and 30 minutes after exercise. Following 30 minutes of rest, the implanted pacemaker was programmed to the VVT mode and driven by an external pacemaker via a skin electrode. The second exercise test (T2) was then performed and the rate of the external pacemaker was progressively changed to reproduce exactly the rate observed during T1 at the same exercise stress. Atrial natriuretic factor (ANF) levels were determined at rest, at regular intervals during exercise, and 30 minutes after exercise. ANF levels and release were statistically higher during rate matched ventricular, than DDD pacing. It is concluded that preservation of AV synchrony reduces ANF release induced by heart rate acceleration during exercise.

[Carotid sinus hypersensitivity associated with a treated otorhinolaryngologic cancer. Study of 103 patients]

The incidence and characteristics of carotid sinus hypersensitivity were investigated in a homogeneous population of patients undergoing radiotherapy and surgery for ear, nose and throat (E.N.T.) cancers. Among the 103 patients who were thus treated but had none of the risk factors usually correlated with the disease investigated, 30 percent showed evidence of mainly vasodepressive (87 percent) carotid hypersensitivity when subjected to carotid sinus massage accompanied by electrocardiography and intra-arterial blood pressure measurement. The large number of positive responses, as well as the good reproductibility of this provocation test and its concordance with the site of local treatment suggest that surgery contributes to the genesis of the abnormality. Owing to the considerable variations in the type of response obtained, carotid sinus hypersensitivity should systematically and repeatedly be searched for in cases of syncope in patients treated for E.N.T. cancer.

[Evaluation of beta-adrenergic blockader therapy in vasovagal syncope reproduced by head-up tilt test]

Increased sympathetic tone is one physiopathological mechanism of vasovagal syncope. In this case, betablocker therapy is logical. The reports in the literature suggest that the head-up tilt test can reliably reproduce vasovagal syncope. Ten patients (4 men and 6 women, mean age 59 +/- 18 years) who suffered from recurrent vasovagal syncopes (2 to 10 attacks in 6 patients and more than 10 in the other 4) with a positive initial head-up tilt test (syncope or severe dizziness with marked hypotension after a maximum of 40 minutes at 60 degrees) were treated with atenolol (200 mg daily in 7 cases and 100 mg daily in the other 3). A second head-up tilt test was performed 15 +/- 6 days later under betablocker therapy; this test was negative in 7 and remained positive in 3 cases. Irrespective of the result, the 10 patients followed the same therapy at the same dosage. After 9 +/- 5 months, 3 patients had another syncopal attack; 2 stopped taking their medication and the third patient continued the betablocker because there was a marked reduction in the frequency of his attacks. There were no further syncopal episodes during follow-up of the other 7 patients. The medium-term efficacy could not be predicted from the results of the second head-up tilt test. The following conclusions may be drawn from this study: The head-up tilt test becomes negative in 70% of cases after introducing betablocker therapy, assuming a 100% reproductivity. This treatment is effective in over half the patients at medium term and should be considered in patients with recurrent vasovagal syncope.

[Sequential revascularization of anterior myocardium using the internal mammary artery. A year-long clinical and angiographic follow-up]

One hundred and twenty-one consecutive patients (104 men, 17 women; mean age 56 +/- 7.8 years) underwent sequential mammary artery grafting for anterior (left anterior descending or diagonal arteries) wall revascularisation. There was one death (0.8%) and five myocardial infarctions (4.2%) including two anterior infarcts during the first 30 postoperative days. All survivors were reviewed at one year. Of these 120 patients, 77 (64%) accepted control coronary angiography on average 456 +/- 143 days after surgery. One internal mammary artery anastomosed to 2 diagonal arteries was occluded. All the other latero-lateral anastomoses were patent. There was, however, one 60% stenosis. Three termino-lateral anastomoses on the left anterior descending artery were occluded and 2 others stenosed (40% and 60% luminal narrowing, respectively). Four internal mammary arteries were narrowed 2 because of stenosis and 2 because of the small calibre of the receiving artery. The patency rate considering the total number of anastomoses was therefore 96.8%. These results show that sequential internal mammary artery grafting for myocardial revascularisation does not increase the number of perioperative complications and is associated with a low rate of occlusion on the left anterior descending artery at one year. This surgical technique may therefore be used routinely.

[Evaluation of the normal bioprosthetic Intact aortic valve by Doppler echocardiography]

The Medtronic Intact is a recently commercialized porcine bioprosthesis. Its function and ultrasonic characteristics have not been widely studied. The authors performed a prospective Doppler echocardiographic study of 38 patients with Intact bioprosthesis (n. 19:1, n. 21:10, n. 23:9, n. 25:14, n. 27:3, n. 29:1) implanted in the aortic position and without clinical signs of dysfunction over a period of 8 +/- 5 months after surgery. The following parameters were measured: maximum and mean velocities, maximum and mean transprosthetic pressure gradients, permeability index (PI) or the ratio of subaortic to transprosthetic velocities, and the effective prosthetic surface area (S) calculated using the continuity equation. The PI and S were calculated by two methods, the first using the ratio of maximum velocities (PI1 and S1) and the second using the ratio of the velocity-time integrals (PI2 and S2). The global results were: Vmax 2.65 +/- 0.4 m/s range 1.9 to 3.7 m/s), maximum pressure gradient 29 +/- 9 mmHg (range 15-55 mmHg), mean pressure gradient 16.8 +/- 5.6 mmHg (range 9-32 mmHg), PI1 37.8 +/- 4.5 p. 100 (range 26-48%), PI2 39.1 +/- 5.5 p. 100, S1 1.25 +/- 0.19 cm2 (range 0.96-1.7 cm2) and S2 1.29 cm2 +/- 0.17 cm2. Minimal central prosthetic valve regurgitation was observed in 2 cases (5%). No correlations were found between the size of the prosthesis and blood flow velocities, pressure gradients or permeability indices. On the other hand, a correlation was observed between S and the size of the prosthesis (r = 0.88, p less than 1.10(-6) (S1); r = 0.80, p less than 1.10(-6) (S2)).(ABSTRACT TRUNCATED AT 250 WORDS)

[Regression of dilated cardiomyopathy in a chronic alcoholic patient after abstinence from alcohol]

The authors report the case of a 28 year old alcoholic who was admitted to hospital for cardiac failure in 1982 due to a dilated cardiomyopathy. The clinical and paraclinical signs disappeared after cessation of alcohol intake. Three years after abstaining from alcohol, the electrocardiogram, echocardiogram and isotopic ventriculography are normal. This case illustrates the necessity of absolute cessation of alcohol intake in patients with dilated cardiomyopathies.

[Painless myocardial ischemia. Comparison of 2 groups of patients with a positive exercise test after myocardial infarction]

Myocardial ischemia usually presents with chest pain, the characteristics of which are well known. However, anginal pain may be absent during true ischemia, an entity known as painless or silent myocardial ischemia. Does this type of ischemia have special clinical, angiographic or ergometric characteristics after posterior myocardial infarction (MI)? In order to answer this question 183 consecutive patients with recent posterior MI who had undergone coronary angiography and who had positive exercise stress tests on bicycle ergometers were separated into two groups depending on whether they had experienced at least one episode of pain after the acute phase of myocardial infarction or during the exercise stress test (Group S: 83 patients, average age 54 +/- 10 years) or not (Group A: 100 patients, average 54 +/- 8 years). The following parameters were commoner in Group A: cigarette smoking, heart rate and load developed during exercise stress testing provoking electrical signs of ischemia, single vessel disease on coronary angiography, long-term medical treatment. On the other hand, the following parameters were statistically more frequent in Group S: hypercholesterolemia, preinfarction angina, degree of ST depression during exercise testing, reperfusion of the distal vessels of the occluded artery responsible for the infarct by a collateral circulation, triple vessel disease and surgical treatment. However long-term follow-up (average 3 years) shows that mortality and recurrence of MI are similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Value of the head-up tilt test in the etiologic diagnosis of syncope]

The cause of brief syncopes is discovered in only two-thirds of the cases at most. The purpose of this study was to quantify the value of the head-up tilt test in patients whose syncope remained "causeless" after a "conventional" investigation. Forty-nine patients entered the study on the following criteria: at least one syncope, no conduction disturbances or normal electrophysiological study, physiological response to carotid sinus massage, absence of postural hypotension and assessable tilt test. The head-up tilt test was performed under blood pressure and electrocardiographic monitoring in three stages: dorsal decubitus during 20 min, 60 degrees tilting during 20 min and, if nothing happened, isoprenaline injection. The test was positive (i.e. produced syncope or at least lipothymia) in 12 patients (24.5 per cent). In all cases the loss of consciousness was associated with a deep fall in blood pressure, but prolonged ventricular pause never occurred (2 patients had bradycardia at about 30 beats/min). The head-up tilt test is a non-invasive examination which in one-quarter of the cases provides a diagnosis of vasovagal syncope when no other diagnosis could be made; it reproduces the syncope, which is rarely done by other investigations, and it deserves to be include in the evaluation of unexplained syncopes.

[Left auricular dilatation in calcified aortic stenosis in adults]

Two groups of patients of comparable age, one comprising 12 subjects without detectable cardiac disease and the other comprising 38 patients with calcific aortic stenosis (CAS) underwent clinical, electrocardiographic, echocardiographic and haemodynamic studies to assess the degree and significance of left atrial hypertrophies in CAS. The volume of the left atrium (LA) was globally increased in CAS (maximum volume 68 per cent: 26/38) and LA ejection fraction was decreased in 60 per cent of patients (23/38). However, the maximum volume was only moderately greater than that of normal subjects (+38 per cent). The most specific non-invasive investigation for left atrial assessment is echocardiography. There was a linear relationship between LA angiographic volume and echocardiographic antero-posterior dimension (r = 0.43; p less than 1 x 10(-2)). The duration of the P wave in S2 was a specific (75 per cent) but relatively insensitive (27 per cent) sign of LA dilatation in pure CAS. On the other hand, the Morris index based on the surface of the P terminal force in V1 was quite sensitive (77 per cent) but not very specific (25 per cent). The maximum LA volume was not related to left ventricular volume, the severity of CAS, diastolic indices of compliance or left ventricular mass. However, the minimum LA volume (after atrial systole) was related to left ventricular end diastolic (r = 0.35, p less than 0.05) and end systolic volume (r = 0.34, p less than 0.05). The LA ejection fraction was inversely related to mean pulmonary capillary pressure (r = 0.34, p less than 5 x 10(-2).(ABSTRACT TRUNCATED AT 250 WORDS)

[Calcified aortic valve stenosis in adults. Analysis of supra- and infra-hissian conduction disorders]

The association of intraventricular or atrio-ventricular conductive disorders with a calcified aortic stenosis, is a classical notion demonstrated by the close anatomical relationships between aortic valve and conduction pathways. These conductive disorders have been, for quite some time, analyzed on standard electrocardiograms, but, since a few years, the recording of the bundle of His potential has become the technique of choice. However, studies regarding this subject are few, based on very small and sometimes heterogeneous groups of patients. Sixty six consecutive patients hospitalized for a narrow aortic stenosis have agreed to be subjected, before valve replacement, to a recording of the bundle of His potential. Thirteen of them (19.7%) show a HV interval exceeding 55 ms or a pathological H deflexion (twisted and lasting 35 ms). None of the pre-operative parameters that were analyzed (black-out, left ventricular function, ventriculo-aortic gradient, calculated valvular area, magnitude of valvular and ring calcifications), seem correlated with the increased HV interval. These results cross-check those reported in most of the literature.

[Short loss of consciousness: etiology and diagnostic approach. Results of a prospective study]

Transient loss of consciousness is a frequent reason for hospitalization, but very few prospective studies have been devoted to this topic. Our study involved 150 patients who were admitted for sudden and total loss of consciousness (syncope) with spontaneous return to normality. All patients underwent thorough physical examination, standard laboratory tests, electrocardiography (ECG) and radiography of the chest. Depending on the results of this first evaluation, the patients were investigated for postural hypotension and had carotid sinus massage, electroencephalography (EEG), computerized tomography of the brain, cardiac Holter recording, electrophysiological exploration and, if necessary, other special examinations. The cause of the syncope was found in 93 cases (62 per cent); it was cardiac in 39 cases (bradycardia 25, tachycardia 14), vascular in 20 cases (vagal 14, postural hypotension 6), epileptic "grand mal" type in 32 cases and "miscellaneous" in 2 cases. The syncope occurred in a state of acute drunkenness in 14 cases and was unquestionably due to the absorption of medicines in 6 cases. Clinical findings and ECG or EEG provided the aetiological diagnosis in 82.7 per cent of the patients and the other, sophisticated examinations in 17.3 per cent. These results are similar to those of other prospective studies found in the literature. It may be concluded that the causes of the syncope are only found in about 2 out of 3 cases, that clinical data are all-important in the diagnostic approach and that complementary examinations are either unnecessary or yield little that is not already suggested by clinical examination.

[Aortocoronary bypass with 10 years' follow-up. Apropos of 183 cases]

Between 1970 and 1972, 183 patients were admitted to the CMC Foch (Pr D. Guilmet) for saphenous vein aorto-coronary bypass surgery. Ten years later a questionnaire was sent to the patient and his cardiologist and the two replies were analysed. Before surgery, all patients had invalidating angina: 12 p. 100 had unstable angina, 61 p. 100 had previous myocardial infarction. Preoperative coronary angiography showed triple vessel disease in 64,5 p. 100, double vessel disease in 18,6 p. 100 and single vessel disease in 14,2 p. 100. There hundred and thirty two grafts were performed (average 1,8 per patient); 42 endarteriectomies were also carried out, 35 on the right coronary artery. Complete revascularisation was achieved in 95 cases (52 p. 100). The incidence of perioperative infarction was 17,5 p. 100 and operative mortality was 7,6 p. 100. Thirty two patients (19 p. 100) died during the 10 year study period; 11 deaths were of cardiovascular origin. The 10 year actuarial survival rate was 66 p. 100. Half the patients are asymptomatic and nearly two thirds take no anti-anginal therapy. The patency of the grafts was chacked in about half the cases and was found to be 72,8 p. 100 at one year. From the professional point of view, two thirds of patients returned to full time working one year after surgery. The degree of activity at 10 years is only known in 87 cases; half these patients are working and a quarter have retired normally. This study shows that: --coronary bypass surgery has excellent long-term effects on symptoms; --the incidence of infarction and survival are comparable to other reported studies; --patients with triple or double vessel disease may have lived longer after surgery than had they been treated medically.