Divergent pathways mediate the induction of ANF transgenes in neonatal and hypertrophic ventricular myocardium.

To determine whether similar or divergent pathways mediate atrial natriuretic factor (ANF) induction in neonatal and hypertrophied adult ventricular myocardium, and to assess whether studies using an in vitro model system of hypertrophy have fidelity to the in vivo context during pressure overload hypertrophy, we generated transgenic mice which harbor either 638 or 3,003 bp of the rat ANF 5' flanking region ligated upstream from a luciferase reporter. Luciferase activity in the ventricles of day 1 transgenic neonates was 8-24-fold higher than the levels expressed in the ventricles of adult mice. Adult mice expressed the luciferase reporter in an appropriate tissue-specific manner. Transverse aortic constriction of adult mice harboring ANF reporter transgenes demonstrated no significant increase in reporter activity in the ventricle. These findings demonstrate that distinct regions of the ANF 5'-flanking region are required for inducible expression of the ANF gene in the hypertrophic adult ventricle compared with those required for atrial-specific and developmentally appropriate expression in the intact neonatal heart. Furthermore, the cis regulatory elements necessary for induction of ANF expression in endothelin-1 or alpha 1-adrenergically stimulated cultured neonatal ventricular myocytes are not sufficient for induction in the in vivo context of pressure overload hypertrophy.

[Value of the negative U wave during exercise test in the diagnosis of coronary insufficiency]. / Intérêt de l'onde U négative au cours de l'épreuve d'effort dans le diagnostic de l'insuffisance coronaire.

In order to determine the value of inversion of the U wave during exercise for the diagnosis of coronary insufficiency, the stress tests of 227 patients were reviewed and confronted with the results of coronary angiography which showed 93 subjects with angiographically normal arteries and 134 subjects with left anterior descending disease; 37 patients had single vessel disease (Group I), 38 had double vessel disease (Group II) and 59 had triple vessel disease (Group III). When compared to the two classical criteria, anginal pain and less than or equal to 1 mm ST depression, inversion of the U wave was more specific: 82.8 +/- 7.6 p. 100 vs 77.4 p. 100 for anginal pain, and 66.7 +/- 9.6 p. 100 for ST depression. The sensitivity of this new sign for the detection of coronary insufficiency was 26.9 +/- 7.5 p. 100 vs 80.6 +/- 6.7 p. 100 for ST depression and 56.7 +/- 8.4 p. 100 for anginal pain. The positive predictive value of U wave inversion on effort was 70.9 +/- 12 p. 100 compared to 77.7 +/- 6.9 p. 100 for ischaemic ST depression and 78.3 +/- 8.2 p. 100 for induced anginal pain. Conversely, in angiographically normal coronary arteries, the absence of U wave inversion had a negative predictive value of 44.8 +/- 7.4 p. 100 compared to 70.5 +/- 9.5 p. 100 for the absence of ischaemic ST changes and 55.4 +/- 8.5 for the absence of anginal pain. These results confirm previously published data.(ABSTRACT TRUNCATED AT 250 WORDS)

[Variations in the amplitude of the Q wave at V5 during computerized exercise test. Value in the diagnosis of coronary insufficiency]. / Etude des variations d'amplitude de l'onde Q en V5 au cours de l'épreuve d'effort informatisée. Valeur dans le diagnostic de l'insuffisance coronaire.

The aim of this study was to evaluate the diagnostic value of changes in Q wave amplitude in the V5 chest lead in coronary artery disease, especially for the detection of significant (greater than or equal to 75% narrowing) left interior descending disease. The stress tests of 227 patients were reviewed and confronted with the results of coronary angiography in 93 patients with angiographically normal arteries, and 134 patients with left anterior descending disease of the latter, 37 had single vessel disease, 38 had double vessel disease and 59, triple vessel disease. The average values of the Q wave amplitude in V5 at the peak of effort were 0.97 +/- 1.04 mm in the control group; 0.53 +/- 0.65 mm (p less than 0.01) in the group with single vessel disease; 0.46 +/- 0.66 mm (p less than 0.01) in the group with double vessel disease and 0.64 +/- 0.9 mm (p = 0.04) in the group with triple vessel disease. The mean variations of the amplitude of the Q wave in lead V5 on effort in the same group of patients were: +0.55 +/- 0.73 mm (p less than 0.001); + 0.11 +/- 0.66 mm (NS); + 0.02 +/- 0.5 mm (NS) and + 0.05 +/- 0.53 mm (NS), respectively. The Q wave in lead V5 was generally deeper on effort in the control group and the average variation in its amplitude was statistically significant only in this group. In the coronary patients, the Q wave in lead V5 was generally smaller and its amplitude did not change significantly on effort.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pulsed and continuous Doppler in qualitative and quantitative diagnosis of mitral insufficiency]. / Apport du Doppler pulsé et continu au diagnostic qualitatif et quantitatif d'insuffisance mitrale.

The aim of this study was to assess the diagnostic value of pulsed and continuous wave Doppler in mitral regurgitation. One hundred and twenty-one patients (64 women and 57 men aged 13 to 76 years, average 54 years) investigated for mitral regurgitation or ischaemic heart disease underwent left ventricular angiography and continuous wave and pulsed Doppler echocardiography. In addition to clinical examination, they also underwent M mode, 2D echocardiography and phonocardiography. They were divided into two groups according to the presence or absence of mitral regurgitation on angiography, chosen as the reference method. Group I comprised 51 patients with angiographic regurgitation, and Group II 70 patients without mitral regurgitation. The sensitivity of the Doppler examination was 98%. Of the 51 patients in Group I there was only one false negative in a patient with doubtful angiographic regurgitation in the context of an endocardial cushion defect. In comparison, the sensitivity of clinical examination and phonocardiography were 74.5% and 80% respectively; 13 cases of mitral regurgitation on angiography and Doppler echocardiography had no auscultatory signs. The specificity of the Doppler examination was 92.8%; 5 of the 70 patients in Group II had unquestionable systolic turbulence in the left atrium and 2D echocardiography showed the possible mechanism of these valvular leaks in 3 cases: 1 bivalvular prolapse, 1 rheumatic valvular thickening and 1 papillary muscle dysfunction. We interpret these 5 cases as being true mitral regurgitation but intermittent or too slight to be visible on angiography. The positive predictive value of systolic turbulence in the left was 90.9% and the negative predictive value was 98.4%.(ABSTRACT TRUNCATED AT 250 WORDS)

[New criteria for a positive exercise test]. / Les nouveaux critères de positivité de l'epreuve d'effort.

In this paper, the author reviews the recently developed criteria for a positive stress test. The "nearly ischaemic" appearance in which the ST segment is depressed by greater than or equal to 1.5 mm and slowly rises (slope of less than or equal to 1 millivolt/second) to a value which is predictive in symptomatic patients, of 70 p. cent in favour of coronary artery disease and 40 p. cent in favour of multiple vessel disease. The increased amplitude of the R wave in V5 immediately after effort is more a sign of left ventricular dysfunction than of coronary artery disease. The decreased amplitude of the Q wave in V5 and V6 at maximal effort is a very sensitive (82%) and very specific (88%) sign of left coronary or anterior interventricular artery disease. Similarly, inversion of the U wave in V5 on effort is a very sensitive and specific (97%) sign of left coronary or anterior interventricular artery disease. The major value of these new criteria is to help recognise the false negative results of the stress test, which can be as high as 50% of cases in patients with one vessel disease.

[Fab fragments of antidigoxin antibodies and acute digitalis poisoning]. / Fragments Fab d'anticorps antidigoxine et intoxication digitalique aiguë.

Acute digitalis intoxication is infrequent and severe. The mortality rate is between 15 and 20 per cent. Its treatment has been greatly improved with the appearance, in 1976, of a specific serotherapy: Fab fragments of antidigoxin antibodies. The clinical experiment reported in the literature relates to approximately one hundred cases and establishes that this therapy has a practically constant and non dangerous efficacy. The lack of availability of these fragments Fab represents presently the only obstacle to the development of this treatment, but the use of monoclonal antibodies, already available experimentally, should, in the future, circumvent this last hurdle.

[Changes in amplitude of the R wave in V5 during a computerized exercise test: value in the diagnosis of coronary insufficiency]. / Etude des variations d'amplitude de l'onde R en V5 au cours de l'épreuve d'effort informatisée: valeur dans le diagnostic de l'insuffisance coronarienne.

In order to determine the real value of the amplitude variations of the R wave V5 during a stress test, in the recognition of coronary insufficiency, the stress tests of 227 patients were reviewed and compared to the results of coronary angiography. This permitted to find 93 patients with healthy coronaries and 134 patients presenting an involvement of the anterior inter-ventricular artery (AIVA); 37 have a one-vessel disease, 38 have a two-vessel disease, 59 a tri-vessel disease. Quantitative analysis of the modifications of the R wave in V5 during stress, finds mean values of amplitude variations of 1.46 +/- 2.65 mm (p less than 10(-7)) in the reference group; + 1.36 +/- 3.03 mm (p less than 0.01) in patients with a one-vessel disease; +/- 2.02 +/- 2.73 mm (p less than 10(-5)) in patients with two-vessel disease; +/- 1.77 +/- 2.82 mm (p less than 10(-6)) in patients with three-vessel disease. Mean variations are not significantly different from one group to the other and do not permit to individualize a specific evolutive profile in favor of a coronary disease. Considering the absence of alterations or the increase of the amplitude of R in V5 during stress as a pathological response to a coronary insufficiency.(ABSTRACT TRUNCATED AT 250 WORDS)