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Biomedical subjects

P Louis

Publications and source records attributed to P Louis.

At least 91 records · Page 5Linked to original sources
PubMed1993

[Incidence of inducible supraventricular tachycardia in dysplasia of the right ventricle].

Arrhythmogenic right ventricular dysplasia (ARVD) is classically associated with ventricular tachycardia and the prevalence of supraventricular tachycardia in this condition is not well known. The aim of this study was to observe the response of 20 patients with ARVD to programmed atrial stimulation and compare it with 150 subjects without cardiac disease or spontaneous supraventricular tachycardia. The protocol used 2 atrial extra-stimuli delivered on 3 paced cycles. Programmed atrial stimulation with 1 extrastimulus was repeated after infusion of 20 to 30 micrograms of Isoproterenol. Sustained supraventricular tachycardia could be induced in 13 patients with ARVD (65%) and 17 control subjects (11%) (p < 0.001). It was not possible to distinguish patients with inducible supraventricular tachycardia from those without inducible arrhythmias by electrophysiologic parameters. Isoproterenol facilitated the induction of VT but not supraventricular tachycardia. Three patients with inducible supraventricular tachycardia developed spontaneous atrial fibrillation. In conclusion, there is a relatively high incidence of inducible supraventricular tachycardia in ARVD: Isoproterenol does not facilitate this tachycardia, contrary to ventricular tachycardia.

Adult↗
PubMed1993

[Myocardial ischemia caused by the injection of dipyridamole followed by low level exertion on an exercise bicycle].

The purpose of this study was the feasibility, safety and analysis of the ischemic nature of the association of an injection of dipyridamole and an exercise test at low level exertion on an exercise bicycle for 4 minutes. The ischemic nature of this combination was assessed on the basis of three criteria: the onset of angina-type pain, electrical changes and scintigraphic abnormalities. The test could be carried out by all patients and the most common adverse events were headache (6.5%) and heartburn (3.5%). The 17 patients in this study who had one or more stenoses in excess of 70% presented with angina-type pain (3/17); electrical abnormalities (9/17) and scintigraphic abnormalities in all cases. Of the six patients who had lesions between 50 and 70%, 1 presented with angina symptoms, 2 with electrical abnormalities and 5 with scintigraphic abnormalities. Seven patients in this study showed no significant lesions when subjected to coronary artery angiography. However, angina-type pain and electrical signs were observed in 2 cases and one false positive result by scintigraphy. This study shows that it is possible to combine the injection of dipyridamole with an exercise test involving a low level of exertion on an exercise bicycle which gives a good diagnostic value to the CT scan. The frequency of clinical and electrical signs of ischemia makes it necessary to take the same precautions as for a peak exercise test.

Aged↗
PubMed1993

[Spontaneous coronary dissection. Apropos of 2 cases].

Spontaneous coronary dissection is a rare and still poorly understood pathological disease entity; the authors report two cases in which the diagnosis was reached in the context of incipient necrosis in young patients. A review of the literature reveals the main characteristics of this problem: the clinical aspect is generally that of acute coronary failure with the constitution of an infarction. The subjects are young with no risk factor but some cases of combination with a disease affecting the elastic tissue have been described. Female gender and the post-partum phase are promoting factors. Diagnosis was long established by means of autopsy but can now be based on coronary angiography. Histologically, the lesion is a hematoma which dissects the arterial wall between the internal two thirds and external third of the media. The main etiological hypothesis is acquired or congenital fragility of the media, which promotes the formation of a dissecting hematoma, however the triggering phenomenon remains poorly understood.

Adult↗
PubMed1993

[Dilated cardiomyopathy disclosing dermatopolymyositis. Management].

Cardiac involvement in dermatopolymyositis is common but rarely symptomatic. Cardiac failure as the presentation is very rare. No correlation exists between the severity of muscular involvement and cardiac involvement. Myocarditis is not uncommon and must be borne in mind if CK MB are above 3% of total CK. It is always associated with electrocardiographic abnormalities. Corticosteroids remain first line treatment. They generally lead to regression of cardiac problems which are usually of secondary importance. If cardiac involvement is severe, the spectacular action of venoglobulins should lead to their use being envisaged from the outset, combined with corticosteroids.

Cardiomyopathy, Dilated↗
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↗