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Biomedical subjects

J Bardet

Publications and source records attributed to J Bardet.

At least 55 records · Page 3Linked to original sources
PubMed1988

[Hemodynamic effects at rest and exertion of a new partial beta-agonist (cicloprolol) in moderated cardiac failure].

The haemodynamic effects of cicloprolol, a new partial beta 1-adrenoceptor agonist, were investigated at rest and during exercise in 10 patients with moderate heart failure. At rest, cicloprolol (0.10 mg/kg i.v.) increased heart rate by 8 p. 100 (80.6 +/- 5.7 vs 74.7 +/- 11.9 beats/min; p less than 0.05), cardiac index by 17 p. 100 (3.74 +/- 0.57 vs 3.20 +/- 0.41 l/min/m2; p less than 0.001) and stroke index by 6 p. 100 (46.3 +/- 8.3 vs 43.7 +/- 8.8 ml/beat/m2; p less than 0.05). Left ventricular end-diastolic pressure was reduced by 35 p. 100 (9.9 +/- 5.0 vs 15.2 +/- 7.4 mmHg; p less than 0.01). There were no significant changes in aortic pressure. Systemic vascular resistance decreased by 15 p. 100 (1,030.8 +/- 234.6 vs 1,209.6 +/- 319.7 dynes.s.cm-5; p less than 0.01). During moderate exercise (114 +/- 13 watts) in supine position, cicloprolol induced a 10 p. 100 reduction of tachycardia (99.7 +/- 10.2 vs 112.2 +/- 16.5 beats/min; p less than 0.01), a 6 p. 100 decrease of mean aortic pressure (112.4 +/- 19.7 vs 119.5 +/- 19.2 mmHg; p less than 0.01) and an 8 p. 100 decrease of cardiac index (5.42 +/- 0.63 vs 5.88 +/- 0.75 l/min/m2; p less than 0.001). There were no significant changes in left ventricular filling pressure and stroke index. When data obtained at rest and during exercise were pooled, an inverse linear relationship (p less than 0.01) was found between heart rate before treatment with cicloprolol and cicloprolol-induced variations in heart rate and cardiac index.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1987

Retrograde catheterization of left ventricle through mechanical aortic prostheses.

Twenty-three patients who had undergone aortic valve replacement with a mechanical aortic valve prosthesis (ball-valve: 17, tilting-disc: 6) were investigated by retrograde left ventricular catheterization using a 6 F pigtail catheter. Twelve of these 23 patients also had had combined aortic and mitral valve replacement. To assess the magnitude of the catheter-induced aortic regurgitation and its effect on left ventricular and mitral valve function, 10 patients (group 1) were simultaneously investigated by the transseptal route (8 patients) or direct left ventricular puncture. The 13 other patients (group 2) were studied only by the retrograde crossing of the aortic valve prosthesis. In group 1, placement of the catheter across the valve induced an increase in heart rate (+12%), in left ventricular end-diastolic pressure (from 17.2 +/- 9.6 to 33.3 +/- 12.0 mmHg), a decrease in aortic systolic (-19%) and diastolic (-25%) pressures, and left ventricular systolic pressure (-10%). Transvalvular aortic pressure gradient increased from 15.4 +/- 8.2 to 23 +/- 12.1 mmHg. Pre- and post-crossing pressure gradients were linearly correlated (r = 0.93). Left ventricular end-diastolic volume increased slightly but significantly (+9%), ejection fraction remained unchanged. Pre- and post-crossing regurgitation fractions were linearly related (r = 0.98). Hence, the magnitude of catheter-induced aortic regurgitation averaged 27% whether or not a pre-crossing regurgitation was noted. In group 2, retrograde crossing of the aortic valve prosthesis induced similar hemodynamic changes. There were no catheterization-related complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1986

[Diagnosis of atrial septal defects by contrast echocardiography with sensitivity increased by coughing].

The aim of this study was to assess the sensitivity of contrast echocardiography in the diagnosis of permanent (atrial septal defects, ASD) and transient (patent foramen ovale, PFO) interatrial communications under basal conditions, after Valsalva manoeuvres and coughing. Sixty-four patients suspected of having defects of the interatrial septum were studied. The results of echocardiography were compared with those of cardiac catheterisation, the classical method of reference. The sensitivity of contrast echocardiography was significantly improved in the diagnosis of PFO by the cough test (100%) compared with contrast echocardiography during spontaneous respiration (55%). Similarly, the cough test increased the sensitivity of contrast echocardiography in the diagnosis of ASD (96% compared to 83%). The specificity was good in both cases, about 90%. The cough test was a better method (98%) than Valsalva manoeuvres (59%) for the potentiation of interatrial right-to-left shunts. The results of echocardiography and catheterisation explain the mechanism of the right-to-left shunt during spontaneous respiration, Valsalva manoeuvres and coughing. The passage of the microbubbles from the right to the left atrium occurs during early systole when the atrioventricular valves are closed. The right-to-left shunt is potentiated by provocative manoeuvres. The demonstration of a right-to-left shunt by contrast echocardiography therefore indicates the presence of an interatrial communication; our results show that this non-invasive technique is a reliable method of diagnosing ASD and PFO.

Adolescent↗
PubMed1985

[Isolated stenosis of the anterior interventricular artery. Comparison of the effects of medical and surgical treatment (in a randomised series)].

Forty-five patients presenting with unstable angina having 70 p. 100 stenosis of the left anterior descending artery judged acceptable for coronary bypass surgery were randomly allocated, using a table of random numbers, for medical (21 patients) or surgical treatment (24 patients). There were no significant differences between the two groups with regards to age (53 +/- 10 years for the medical group; 55 +/- 9 years for the surgical group), the length of follow-up (55 +/- 26 vs 61 +/- 28 months), left ventricular end diastolic volumes (87 +/- 27 vs 84 +/- 18 ml/m2) or ejection fraction (62 +/- 8 vs 59 +/- 11 p. 100). There were no deaths in the medical group; two patients developed uncomplicated myocardial infarction 19 days and 7 months after coronary angiography, respectively. 5 patients had recurrent angina and were referred for surgery. This operation of second intention did not pose any special problems. 6 of the 14 patients with stenosis of the LAD before the origin of the first septal artery had complications (infarction in 1 case, recurrent angina in 5 cases). In the surgical group, 1 patient died in the immediate postoperative period, of resistant cardiac arrhythmia; 2 patients developed uncomplicated peroperative myocardial infarction; 21 patients had no complications at all. The surgical patients were heparinised in the immediate postoperative period and anticoagulant therapy was continued with oral vitamin K antagonists for 6 months to 1 year, followed in some cases, by platelet antiaggregant therapy. 20 patients in this group underwent maximal exercise stress testing which was negative in 19 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1984

Potentiation by ammonia of the metabolic effects of pent-4-enoate in isolated rat hepatocytes.

The metabolic effects of pent-4-enoate were studied in isolated rat hepatocytes; 1 mM-pent-4-enoate did not significantly inhibit gluconeogenesis from lactate, alanine and glycerol, but significantly decreased glucose synthesis from pyruvate. The addition of 1 mM-NH4Cl led to a drastic inhibition of glucose synthesis from all these substrates. In hepatocytes incubated with 10 mM-alanine and 1 mM-oleate, pent-4-enoate at 0.05-1 mM slightly inhibited glucose synthesis and ketogenesis. The addition of ammonia resulted in a dramatic potentiation of the metabolic effects of pent-4-enoate. Half-maximum effect of ammonia was observed at 0.2 mM concentration. Concomitant cellular concentrations of ATP and acetyl-CoA were also decreased by the addition of ammonia, as were lactate/pyruvate ratio and beta-hydroxybutyrate/acetoacetate ratio. These data suggest that ammonia seriously interferes with the cellular metabolism of pent-4-enoate and leads to a dramatic potentiation of its effects.

Acetyl Coenzyme A↗
PubMed1984

Controlled, eight-hour haemodynamic study of a sustained-release formulation of isosorbide dinitrate in moderate left ventricular failure.

The aim of the study was to assess the duration of the haemodynamic effects of a new sustained-release oral formulation of isosorbide dinitrate (ISDN). Twenty patients (17 men and 3 women; mean age 60 years) with acute myocardial infarction (10 anterior, 10 inferior) complicated by moderate left ventricular failure took part in a randomized controlled trial. Ten patients were randomly assigned to the placebo group and 10 to the ISDN group, who received 40 mg sustained release isosorbide dinitrate. Haemodynamic variables were measured before treatment, after 0.5 and 1 h and then every 2 hours up to the 8th hour after treatment. There was no significant change in any haemodynamic parameter in the placebo group, during the study period. In the ISDN group there was a significant fall in pulmonary artery diastolic pressure at 4 and 8 h, from 19.0 +/- 1.0 mm Hg to 16.5 +/- 1.2 mm Hg and 15.5 +/- 0.8 mmHg, respectively. The mean pulmonary capillary wedge pressure fell progressively from 17.9 +/- 1.0 to 12.5 +/- 1.2 mmHg at 2 h (p less than 0.001 in comparison with the placebo group. The fall remained significant up to 8 h. There was no statistically significant change in heart rate, cardiac index, systemic blood pressure or systemic and pulmonary vascular resistances. On the whole the cardiac index remained unchanged. There were numerous individual variations of cardiac index in relation to the initial mean pulmonary capillary wedge pressure and the magnitude of its fall following administration of ISDN. The change in cardiac index was inversely correlated with the control cardiac index (r = -0.69, p less than 0.02).

Delayed-Action Preparations↗
PubMed1984

[Aortic insufficiency in Takayasu's disease. Apropos of 3 surgically treated cases and review of the literature].

The author report the cases of three women with aortic regurgitation associated with aneurysmal dilatation of the ascending thoracic aorta. Aortic valve replacement was carried out in the 3 cases, with resection of the aortic aneurysm in 2 cases. Histological examination of the aortic wall in all 3 cases showed non-specific aortitis in the adventitia and media, appearances comparable to those described in Takayasu's disease. The incidence of aortic regurgitation in Takayasu's disease is about 10%. These 3 cases are compared with 30 other cases with histological confirmation in the medical literature, only 9 of which have undergone aortic valve replacement. The mechanism of the aortic regurgitation is analysed: dilatation of the aortic ring, inflammation of the valve cusps, commissural dysjunction or dilatation of the ascending aorta involving the line of commissural insertion. Aortic regurgitation is usually associated with other arterial localisations of the disease, but may also be found alone when the disease seems limited to the ascending aorta. Coronary artery disease, especially ostial, is observed in 30% of patients with this type of aortic regurgitation. Coronary angiography is therefore mandatory before surgery. The arterial involvement may be investigated initially and followed-up by 2 non-invasive investigations = digitalised intravenous angiography (DIVA) and M mode and 2D echocardiography. The two investigations give comparable results with regards to the study of the aorta, but the branches of the aorta and pulmonary arteries can only be investigated by DIVA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Characterization of enzymatic deficiencies of branched chain amino-acid catabolism in human fibroblasts by genetic complementation.

Leucine and Isoleucine metabolism in cultured skin fibroblasts from patients with leucinosis, beta-Ketothiolase deficiency, propionic, methylmalonic and isovaleric acidemia, was compared with that in normal fibroblasts. A simple assay was developed using (U14C) Isoleucine and (U14C) Leucine as substrates. Radioactive incorporation into protein aminoacids were measured. The (U14C) branched chain aminoacid incorporation into proteins provides an estimation of the protein synthesis and the incorporation ratio (14C) Aspartate + (14C) Glutamate/(14C) branched chain aminoacid, measures the integrity of the metabolic pathway. Complementation tests permits to characterize the genetic defect. The incorporation ratio was significantly decreased in blocked pathways, namely in leucinosis and isovaleric acidemia in the presence of (U14C) Leucine and in Leucinosis, beta-Ketothiolase deficiency, propionic and methylmalonic acidemia in the presence of (U14C) Isoleucine. There was a significant restoration of activity in mutant strains with distinct genetic defects after polyethylene-glycol fusion. This assay provides a valuable tool to screen for enzymatic deficiencies of branched chain aminoacid catabolism.

Acetyl-CoA C-Acyltransferase↗
PubMed1983

[8-hour hemodynamic study of 2 sustained-release nitrate derivatives. Comparative double-blind study against placebo].

The aim of this study was to evaluate the duration of the hemodynamic effects of a new slow release preparation of isosorbide dinitrate and to compare its action with placebo and a slow release nitroglycerin preparation whose hemodynamic efficacity has already been demonstrated. The study was undertaken in 30 patients admitted to the intensive care unit during the acute phase of myocardial infarction complicated by left ventricular failure less than 12 hours after the onset of the chest pain. The patient population was uniform: 24 males, 6 females, mean age 61 years. Fifteen patients had anterior infarcts and 15 posterior infarcts. The drugs were administered double blind in a randomised fashion to 3 groups of 10 patients, the initial clinical and hemodynamic characteristics of which were comparable: 10 patients received placebo (placebo group); 10 patients received slow release nitroglycerin in a 7,5 mg gelule (NTG group) and 10 patients received 40 mg slow release isosorbide dinitrate (ISDN group). The following parameters were compared: heart rate, right atrial pressure, pulmonary artery and capillary pressures, systemic arterial pressure, cardiac index and systemic and pulmonary arterial resistances. These parameters were measured before therapy, half an hour, one hour and every two hours up to the 8th hour after drug administration. All patients were in moderate left ventricular failure with an initial mean capillary pressure of 18 mmHg +/- 1,3 mmHg. In the placebo group, none of the parameters studied changed significantly during the study. Pulmonary artery pressure fell significantly by 11 p. cent in the NTG group and 7,5 p. cent in the ISDN group. Mean pulmonary capillary pressure fell progressively in both treatment groups; the change was significant compared to the placebo group from the first hour for the ISDN group, and from the second hour for the NTG group. The fall remained significant at the 8th hour for the ISDN group but not in the NTG group. Cardiac index, systemic blood pressure, systemic and pulmonary arterial resistances did not change significantly. The cardiac index remained stable in the 30 patients, but with a number of individual variations depending on initial mean pulmonary capillary pressure and the importance of its fall after nitrate administration. The authors conclude that the hemodynamic effects of slow release NTG and ISDN in the acute phase of myocardial infarction complicated by moderate left ventricular failure are comparable. Pulmonary capillary pressure was the hemodynamic parameter which underwent the greatest variation in the two treatment groups. Its fall was more prolonged in the ISDN than in the NTG group.

Administration, Oral↗
PubMed1983

[Hemodynamic effects of sublingual molsidomine in patients with or without cardiac failure].

A haemodynamic study was performed in 12 men aged between 28 and 64 years, including 8 with clinical signs of congestive cardiac failure and an ejection fraction of less than 50 per cent. The pulmonary artery pressure, capillary pressure, left ventricular pressure, cardiac output and the arterial and venous oxygen tensions were measured before (T 0) and after sublingual administration of 4 mg of molsidomine (T 15, T 30, T 45, T 60 min) and 3 minutes after a dose of 0.6 mg sublingual trinitrine (given immediately after the measurements made at T 60). The haemodynamic modifications were very significant at the 30th minute and reached a plateau between the 45th and 60th minute. The left and right ventricular filling pressures fell by more than 25 per cent, the aortic pressure fell by 17 per cent. There was a mild decrease (8 per cent) in the cardiac index and the systolic index, without any significant change in the heart rate. The reduction in the cardiac index and the systolic index was not significant in patients with cardiac failure and an ejection fraction of less than 50 per cent. The peripheral vascular resistance fell by 9 per cent. Finally, there was a significant reduction in the cardiac work and power and especially in the pressure-time index per beat and per minute. The administration of 0.6 mg of sublingual trinitrine induced an additional reduction in the aortic pressure with acceleration of the heart rate and a slight increase in the cardiac output, but no additional venodilator effect was detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

[Update on the study of true and false left ventricular aneurysms by 2-dimensional echocardiography].

2D echocardiography is a great advance in the study of left ventricular aneurysms. The wide field of visualisation and the numerous planes of examination obtained from different transducer positions allow precise spatial orientation and reliable analysis of regional wall movement. An aneurysm appears as a clear and constant bulge of a segment of left ventricular wall in both diastole and systole. Antero apical aneurysms are the commonest variety. The sensitivity and specificity of 2D echo in the detection of ventricular aneurysms are high. Thrombosis within the aneurysmal bulge may also be detected (33-38%). Pseudo-left ventricular aneurysms are easily identified as a chamber communicating with the ventricle by means of a narrow neck; the width of this neck is the main echocardiographic feature differentiating pseudo and true ventricular aneurysms. 2D echocardiography gives valuable information on the state of the remaining contractile area, an important prognostic factor when surgical resection of the aneurysm is being considered.

Diagnosis, Differential↗