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Biomedical subjects

R Dorent

Publications and source records attributed to R Dorent.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Chronic constrictive pericarditis. A retrospective study of a series of 84 patients].

Chronic constrictive pericarditis still poses diagnostic and therapeutic problems. A series of 84 cases (59 men-25 women; men age: 46 years) operated between 1979 and 1989 at the Pitié Hospital was reviewed. The majority of patients (72%) were in functional Classes III or IV; 88% had clinical signs of right ventricular failure and 18% had anasarca. The average duration of symptoms before diagnosis was 20 months. Chest X-ray showed pericardial calcification in 40% of cases. A characteristic dip-plateau pressure tracing was obtained in 76% of cases. A specific aetiology was only found in 36 cases (45%), only 12% being of tuberculous origin. A subtotal pericardectomy from phrenic to phrenic was carried out in 75 patients. The absence of planes of cleavage in 9 cases imposed a special operative technique consisting of "patchwork" sectioning of the visceral pericardium. The operative mortality was 2.3% (2 patients: pulmonary embolism and septicaemia). Non-fatal post-operative complications occurred in 8.2% of cases (7 patients). The survival rate excluding operative mortality was 94% at 3 years and 87% at 7 years. No patient was reoperated for recurrent constrictive pericarditis. At the last follow-up appointment, all patients were in functional Classes I or II. The authors conclude that the absence of specific symptoms, the low prevalence of the condition and the change in aetiology related to the decline in tuberculous infection make the diagnosis of chronic constrictive pericarditis very difficult. The diagnostic contributions of new imaging techniques such as CT and MR scanning should be assessed. This series confirms the efficacy of surgical treatment by subtotal pericardectomy.

Adult↗
PubMed1993

Coronary artery vasomotion in cardiac transplant patients with normal coronary angiograms.

In 18 consecutive transplant patients with normal coronary angiograms and without calcium blocker therapy, and in 20 controls, we measured the diameters of the left anterior descending artery using quantitative coronary angiography. Measurements were effected on the frames recorded 5 min or more after intravenous administration of 0.4 mg methylergometrine, and 2 min after subsequent 2 mg bolus intracoronary isosorbide dinitrate administration. The arterial vasodilatory capacity was defined as the ratio of the difference of the largest and smallest arterial diameters and the smallest diameter. We observed normal vasoconstriction of the different coronary arterial segments. Coronary arterial diameter decrease from basal state was about 8% and was more pronounced at the distal segments of the left anterior descending artery. There was no difference of vasodilatory capacity between transplant patients and controls for the proximal and middle portion of the left anterior descending artery, while the difference was highly significant for the distal portion. In eight patients, the decrease of the vasodilatory capacity was beyond the lower limit of the normal range of values. The significance of those quantitative angiographic abnormalities is still unproven. They could be due to early vasomotor capacity blunting after transplantation and to late structural alterations of distal coronary vessels in cardiac transplant patients.

Adult↗
PubMed1993

Results of subtotal pericardiectomy for constrictive pericarditis.

The operative approach to constrictive pericarditis still remains a surgical challenge. Subtotal pericardiectomy through median sternotomy was analyzed retrospectively in a series of 84 patients operated on for chronic constrictive pericarditis at our institution between 1979 and 1989. The mean duration of symptoms prior to diagnosis was 20 +/- 6 months (1-264 months). Preoperatively, 72% of patients were in NYHA class III or IV, presented signs of right cardiac failure (88%) or anasarca (18%). Chest X-ray showed pericardial calcifications in 40% of the patients. Echocardiography revealed pericardial thickening in 62%. Among 62 patients in whom cardiac catheterization was performed, a characteristic dip-and-plateau was found in 47 patients (76%). A specific etiologic factor was identified in only 37 patients: tuberculosis (12%), recurrent acute pericarditis (9%), hemopericardium (9%), radiotherapy (5%), previous cardiac surgery (4%), bacterial infection (2%), myocardial infarction (2%) and connective tissue disease (2%). In 47 patients (55%), the constrictive pericarditis remained idiopathic. In seven patients we performed a redo-operation for previous incomplete pericardiectomy. Subtotal pericardiectomy (from phrenic nerve to phrenic nerve) was performed in 75 patients. A palliative procedure consisting of pericardial "meshing" was performed in nine patients due to an unsatisfactory cleavage plane. Cardiopulmonary bypass was used in four patients for coexistent cardiac lesions. The operative mortality was 2.3% (two patients: septicemia and pulmonary embolism). Seven patients (8.2%) developed early on-lethal complications. The probability of survival for patients discharged for the hospital was 94% at 3 years and 87% at 7 years. There were four late deaths and no reoperation for recurrent constriction.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Bypass↗
PubMed1993

[Endothelin: the vasoconstrictor of the 1990's?].

Endothelin is a recently isolated 21 amino acid peptide with vasoconstrictor activity. It seems to be part of the "hormonal" production by the vascular endothelium and might play a key role in the regulation of vasomotricity. The principal property of endothelin is that it induces an intense and prolonged arterial and venous contraction. Endothelin is secreted by endothelial cells under the influence of various stimuli (thrombin, adrenaline, shearing stress, hypoxia, etc.), then binds to specific membrane receptors thereby increasing the intracellular free calcium concentration. Endothelin has many other vascular and extravascular properties: it has positive inotropic and chronotropic effects, increases renal vascular resistances and reduces the glomerular filtration rate, contracts bronchial and gastrointestinal smooth muscle, induces proliferation of the vascular smooth muscle cells as well as that of fibroblasts and glomerular mesangial cells. Compared with experimental data in animals, human data are still scantly. Plasma endothelin concentration rises in acute renal failure and in chronic renal failure treated by dialysis, diabetes mellitus, essential arterial hypertension, pre-eclampsia and asthma. The development of specific antagonists and endothelin in synthesis inhibitors should soon enable us to specify the modes of regulation of endothelin production before considering applications to therapy.

Animals↗
PubMed1993

[Tricuspid valve replacements in adults. Long-term results].

In the period between January 1979 and January 1989, 72 patients (46 women and 26 men, average age 46 years) out of 697 patients undergoing a tricuspid valve procedure, underwent prosthetic valve replacement for organic tricuspid valve disease. Sixteen patients had pure tricuspid regurgitation (Group I). The causal pathology was essentially traumatic (6 cases) and infections (endocarditis) (5 cases). Fifty-six patients (Group II) had organic tricuspid valve disease associated with a left-heart valvular lesion. The causal pathology was rheumatic fever in 52 cases and endocarditis in 4 cases. In 40 patients (71.5%) the procedure was a reoperation of a mitral and/or aortic and/or tricuspid valve prosthesis. In 21 cases, the initial operation had involved the tricuspid valve. All patients in Group I underwent valvular replacement with a bioprosthesis. In Group II, 40 patients were implanted with a bioprosthesis and 16 with a mechanical valve prosthesis. The follow-up was complete for an average period of 7 years (range 2 to 12 years) for a total of 295 patient-year. The hospital mortality was nil in patients with isolated tricuspid valve disease. Reoperation for deterioration of a porcine bioprosthesis was required after 4 years in 1 case. Terminal cardiac failure was responsible for one late death 7 years after surgery. The hospital mortality was 26.7% (15 patients) in Group II. The actuarial rate of patients free of reoperation at 7 years was 80 +/- 8%. The actual rate of patients free of any prosthetic valve related complication was 78 +/- 2%. The 7 year survival rate excluding operative mortality was 65 +/- 8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1992

Heart transplantation: update.

Clinical application of heart transplantation goes beyond 25 years experience. The main indications for cardiac transplantation remain idiopathic cardiomyopathies and ischemic diseases. To obtain a suitable donor has become progressively more difficult due to the increase of transplants performed and the shortage of donors. Advances in the detection of early rejection, improved organ preservation procedures, and the introduction of new immunosuppressive therapy protocols have produced dramatic results in heart transplantation. Late graft atherosclerosis remains a serious threat despite retransplantation and, in some cases, mechanical cardiac support.

Adolescent↗
PubMed1992

[Infectious complications of heart-lung transplantation].

This study describes the infectious complications in 68 heart-lung transplant patients. We focused interest on early post-transplant infections so called nosocomial pulmonary infections, their exacerbating cofactors their clinical expression, and elements of diagnosis and treatment. Furthermore we describe the principal infections seen during long-term followup, which are opportunist infections caused most often by immunosuppression: Cytomegalovirus infections have a high incidence with serious clinical consequences in heart-lung transplant patients. As well as pneumocystis carinii infections and fungal infections, such as aspergillosis.

Adolescent↗