Search PubMed⌕ Search

Biomedical subjects

P Louis

Publications and source records attributed to P Louis.

At least 19 recordsLinked to original sources
PubMed1995

Programmed ventricular stimulation in survivors of acute myocardial infarction: long-term follow-up.

The prognostic significance of ventricular tachyarrhythmias induced by programmed ventricular stimulation was evaluated in 492 consecutive survivors of acute myocardial infarction (AMI). Holter monitoring, signal-averaged electrocardiogram (ECG) and measurement of left ventricular ejection fraction (EF) were also performed. The protocol used up to 3 extrastimuli. Sustained monomorphic ventricular tachycardia (VT) < 270 beats/min, > 270 beats/min (ventricular flutter) (VFI), and ventricular fibrillation (VF) were induced in 99, 66 and 52 patients, respectively. Long term follow-up (mean 3.7 +/- 2.2 years) showed that most episodes of VT occurred during the first months following AMI (n = 14), but some patients (n = 6) could develop VT as late as 4 years after AMI. Sudden death (SD) (n = 22) always occurred during the first year following AMI. Multivariate analysis demonstrated that EF < 30% and induction of a VT < 270 beats/min were the only predictors for total cardiac death (P < 0.001). EF < 30%, induction of a VT < 270 beats/min and also of VFI (P < 0.05) were predictors for VT and SD: the risk was 4% in patients without inducible VT, 12% in those with inducible VF1, and 21% in those with inducible VT < 270 beats/min. In conclusion, induction of a sustained monomorphic VT < 270 beats/min or > 270 beats/min is a predictor of arrhythmic events during the first year as well as 4 years after myocardial infarction. However the risk of arrhythmic sudden death decreases after the first year, while the risk of VT persists. Because of the low positive predictive value of programmed stimulation (respectively 21% and 12% for the induction of a sustained VT and VFI), we recommended the indication of programmed stimulation in only the patients with one abnormal non-invasive investigation.

Actuarial Analysis↗
PubMed1992

Oldest known Nannopithex (Primates, Omomyiformes) from the early Eocene of France.

Numerous dental remains of Nannopithex zuccolae, n. sp., from the terminal early Eocene locality of Prémontré (Aisne), France, show the lower anterior dentition to be similar to that of other Nannopithex. Similarities include enlarged I1, reduced I2, reduced lower canine, loss of P2, small P3 and large P4. Upper molars, P3 and P4 all present primitive characters, making this species the most primitive as well as the oldest known microchoerid.

Animals↗
PubMed1992

[Isolated hemangioma of the left ventricle. Value of coronaroangiography for the etiological diagnosis].

A four year old child was admitted for investigation of a cardiac murmur and cardiomegaly. Echocardiography showed a large left ventricular tumour, the extension of which was accurately defined by nuclear magnetic resonance imaging and the etiology confirmed by coronary angiography. Holter recordings showed salvoes of ventricular tachycardia. This is an interesting case because, despite echocardiography and nuclear magnetic resonance imaging, the precise nature of the tumour was revealed only by coronary angiography. This investigation also showed a significant decrease of the left ventricular ejection fraction. It is the only described haemangioma complicated by this type of ventricular hyperexcitability. Therefore, coronary angiography would seem to be necessary in the investigation of isolated myocardial masses which remain unidentified by non-invasive methods.

Cardiomegaly↗
PubMed1991

[Programmed ventricular stimulation in unexplained syncope: risk factors for induction of ventricular tachycardia].

The aim of this study was to identify the factors associated with the induction of ventricular tachycardia (TV) by programmed ventricular stimulation in patients with unexplained syncope. Sustained VT was induced in 71 out of 619 patients (11.5%) with syncope. A comparison of subjects with inducible VT and those without inducible VT showed underlying cardiac disease to be more common (89% versus 16%), more Holter abnormalities (Grade IVa ventricular extrasystoles) (60.5% versus 10%) in the first group but that signal-averaged ECG, recorded in 51 cases, was not sufficiently specific to differentiate the two groups (delayed potentials in 57% versus 43%). When syncope occurred in a subject without apparent cardiac disease with a normal Holter recording, inducible VT was rare (1%). On the other hand, when syncope was associated with cardiac disease and/or an abnormal Holter recording, VT could be induced in 45 to 64% of cases. In addition, as inducible VT was associated with severe infrahisian conduction defects in 3 cases, the following strategy is suggested in patients with unexplained syncope: programmed ventricular stimulation should be performed systematically during endocavitary electrophysiological investigation of AV conduction in patients with cardiac disease and if the non-invasive investigations, Holter monitoring or echocardiography, are abnormal.

Cardiac Pacing, Artificial↗
PubMed1991

[Results of programmed ventricular stimulation in induced non-sustained polymorphic ventricular tachycardia and maintenance of stimulation].

Programmed ventricular stimulation risks inducing non-pathological ventricular fibrillo-flutter. The aim of this study was to determine if the induction of a non-sustained polymorphic ventricular tachycardia (over 5 intraventricular reentries) could prevent this incident. One hundred and thirty-three non-sustained polymorphic tachycardias were induced by 2 or 3 extrastimuli during 1450 programmed ventricular stimulation studies. Ventricular stimulation was continued and led to ventricular fibrillo-flutter in 46 cases (Group I); to induction of sustained ventricular tachycardia in 26 cases (Group II) or to no other arrhythmias excepting the non-sustained tachycardia in 61 cases (Group III). The duration of the salvo was similar in all 3 groups. The rate of the induced arrhythmia was significantly lower in Group II (234 vs 290/min). The essential difference between the three groups was the clinical context. Only patients in Group II had previously documented sustained ventricular tachycardia and only patients in Group III had no apparent underlying cardiac disease. These results suggest that the decision to stop programmed ventricular stimulation should be based on the clinical indications of the study. In patients with previously documented or probable sustained ventricular tachycardia, it would seem to be necessary to continue ventricular stimulation irrespective to the rate and duration of the induced non-sustained ventricular tachycardia.

Cardiac Pacing, Artificial↗
PubMed1991

[Results of surgery in mitral valve insufficiency with impaired left ventricular function].

This cooperative study (8 French Cardiology Departments) was undertaken to determine the postoperative outcome of patients with pure, chronic, non-ischemic mitral regurgitation and poor left ventricular function (ejection fraction less than 50%). Seventy-three patients, 48 males and 25 females with a mean age of 55.5 +/- 12.1 years were included. Fifty-eight patients were in Class III or IV of the NYHA Classification. The average cardiothoracic ratio was 0.59 +/- 0.07. Forty-six patients were in atrial fibrillation. The average ejection fraction was 43 +/- 5 per cent (end systolic volume: 97.8 +/- 37.9 ml/m2; end diastolic volume: 175.2 +/- 67.6 ml/m2). Sixty-one patients underwent prosthetic mitral valve replacement and 12 had a Carpentier valvuloplasty. Two patients died after the operation and 20 died during follow-up (average 48.1 +/- 27.6 months), giving a 5 year actuarial survival rate of 69.6 per cent. In the long-term, fifteen per cent of patients were in NYHA Class III or IV. A multivariate Cox analysis showed that the only predictive factors of a poor outcome were age and female sex. These results of surgery for mitral regurgitation with moderate to severely altered left ventricular function were relatively good, but this study does not allow evaluation of the evolution of patients with mitral regurgitation and very poor left ventricular function (no patients with ejection fraction less than 25%).

Actuarial Analysis↗
PubMed1990

Evidence that zero antigen-matched cyclosporine-treated renal transplant recipients have graft survival equal to that of matched recipients. Reevaluation of points.

The value of HLA matching in cadaver renal transplantation (CRT) continues to be debated. It has recently been suggested that increased importance be given to HLA matching for the distribution of cadaver kidneys. Such a policy would add both delay and expense to CRT, which could be justified only by significantly improved results. The results of CRT in 252 cyclosporine treated adult patients transplanted at our institution from November 1984 to April 1989 were reviewed. Kidneys were initially transplanted into crossmatch-negative recipients based on waiting time, regardless of match. From October 1987, a points system, based on United Network for Organ Sharing (UNOS) criteria has been used. Eighty-four pts. with zero antigen match with their donors were compared with 168 pts. sharing 1-6 Ag. Actuarial graft and patient survival were determined by the cumulative life table method and compared using a log rank test. Our results indicated no statistically significant difference in graft survival because of better matching or mismatching. These findings are in keeping with our previously reported long-term results for non-CsA pts. Past predictions of improved graft survival based upon better matching at our institution have not fulfilled expectations, with the exception of 6 Ag matches. In conclusion, increased emphasis on HLA matching with fewer "points" for poorer matches does not appear justifiable.

Adult↗
PubMed1990

[What are the indications for digitalis glycosides in the current treatment of cardiac insufficiency?].

Digitalis was discovered over two centuries ago and has been in everyday use for 100 years: however nowadays it is not considered to be the almost exclusive treatment of heart failure as it used to be with diuretic therapy. In the last decade, our understanding of the physiopathology of heart failure and the body's mechanisms of adaptation have improved and this has lead to the use of new molecules and a different approach to the problem of left ventricular failure. The classical contra-indications and precautions of use of digitalis have been studied in detail. The use of digitalis is contested especially in patients in sinus rhythm or with ischemic heart disease and it is used less often in adult cardiac emergencies. The competition between digitalis and vasodilator therapy is now very apparent in some situations; however, the choice between these two groups of drugs (as treatment of first intention or in association) has to be carefully considered in each individual case. The future of digitalis therapy lies without doubt in pediatric cardiology where it remains irreplaceable.

Clinical Trials as Topic↗
PubMed1989

Successful transplantation after conversion of a positive crossmatch to negative by dissociation of IgM antibody.

Preliminary crossmatching usually eliminates highly sensitized patients from consideration for renal transplantation. However, if the crossmatch is positive because of the presence of IgM antibody, this activity can be eliminated by treatment with the reducing agent Dithiothreitol (DTT). Successful transplantation may then be possible in patients whose crossmatch is positive due to the presence of IgM antibody. After treatment with DTT, the sera of 25 highly sensitized patients were measured for cytotoxicity against a selected panel of 40 cells. Those whose high %PRA could be attributed to blood transfusions or previous transplants did not change with DTT. Only two patients who had developed high panel reactivity, without a clear cause, had little reactivity remaining after DTT treatment of their sera. To select patients whose crossmatch might be rendered negative by DTT treatment, we developed a "minipanel" screening protocol. Patients whose monthly PRA cells increased greater than 30% from baseline had their serum samples treated with DTT to reduce IgM. The treated sera were tested against a panel of six cells. If there was little or no cytotoxicity, it was assumed that IgM antibody was responsible for the positive crossmatches. All subsequent cadaver donor crossmatches were done with and without DTT treated sera. Five patients (2 living-related; 3 cadaver) with current crossmatches positive before, but negative after, DTT treatment continue to have functioning kidneys 3-15 months after renal transplantation. There were no hyperacute rejections. We conclude that patients with IgM antibody can be successfully transplanted if they have a negative cross-match after reduction of IgM antibody in their serum samples. A "minipanel" helps to identify patients who will benefit from DTT treatment.

Adult↗
PubMed1989

[Paraclinical tests in the diagnosis of right ventricle infarction].

Right ventricular infarction is often associated with an inferior myocardial infarction. ECG demonstrates a ST segment elevation in the leads V3R and V4R when taken early. Two dimensional and M mode echocardiography are useful in the differential diagnosis of cardiac tamponade. However they can demonstrate right ventricular functional derangements. Hemodynamic abnormalities are variables: adiastole, features of tricuspid regurgitation.

Electrocardiography↗
PubMed1989

[Right-left auricular shunt caused by patent foramen ovale at a multi-purpose intensive care unit. Apropos of 3 cases].

Three cases of symptomatic right-to-left interatrial shunt through a patent foramen ovale were detected in the course of a case of paradoxical embolism related to a massive pulmonary embolism, a case of refractory hypoxemia after cardiopulmonary bypass and a case of refractory hypoxemia in a patient with tricuspid endocarditis. According to anatomic studies, the incidence of patent foramen ovale is 25-30% in healthy people. In that case any pathological event generating an increase in the right atrial pressure higher than the left atrial pressure may induce a right-to-left shunt with systemic arterial desaturation and possible paradoxical embolization. The reported cases emphasize the advantage of ultrasonic examinations (contrast sonocardiography, pulsated or coloured Doppler) to show the right-to-left atrial shunt. The demonstration of this acquired shunt requires appropriate measures in order to reverse the atrial gradient. Sometimes a specific therapy is required such as caval filter insertion in case of pulmonary embolization or surgical closure of foramen ovale in some patients.

Adult↗