Biomedical subjects

C Bailleul

Publications and source records attributed to C Bailleul.

7 recordsLinked to original sources

PubMed2002

Comparative effects of permanent biventricular and right-univentricular pacing in heart failure patients with chronic atrial fibrillation.

BACKGROUND: One third of chronic heart failure patients have major intraventricular conduction and uncoordinated ventricular contraction. Non-controlled studies suggest that biventricular pacing may improve haemodynamics and well-being by reducing ventricular asynchrony. The aim of this trial was to assess the clinical efficacy and safety of this new therapy in patients with chronic atrial fibrillation. METHODS: Fifty nine NYHA class III patients with left ventricular systolic dysfunction, chronic atrial fibrillation, slow ventricular rate necessitating permanent ventricular pacing, and a wide QRS complex (paced width >or=200 ms), were implanted with transvenous biventricular-VVIR pacemakers. This single-blind, randomized, controlled, crossover study compared the patients' parameters, as monitored during two 3-month treatment periods of conventional right-univentricular vs biventricular pacing. The primary end-point was the 6-min walked distance, secondary end-points were peak oxygen uptake, quality-of-life, hospitalizations, patients' preferred study period and mortality. RESULTS: Because of a higher than expected drop-out rate (42%), only 37 patients completed both crossover phases. In the intention-to-treat analysis, we did not observe a significant difference. However, in the patients with effective therapy the mean walked distance increased by 9.3% with biventricular pacing (374+/-108 vs 342+/-103 m in univentricular;P =0.05). Peak oxygen uptake increased by 13% (P=0.04). Hospitalizations decreased by 70% and 85% of the patients preferred the biventricular pacing period (P<0.001). CONCLUSION: As compared with conventional VVIR pacing, effective biventricular pacing seems to improve exercise tolerance in NYHA class III heart failure patients with chronic atrial fibrillation and wide paced-QRS complexes. Further randomized controlled studies are required to definitively validate this therapy in such patients.

Aged↗

PubMed2002

[MUSTIC trial].

The atrio-bi-ventricular pacing has been used for hemodynamic improvement since 1994, and the MUSTIC trial is the first controlled study assessing this concept. It collected 67 patients with severe and stable heart failure with optimised medical therapy, with sinus rhythm and without any traditional indication for pacing. After two periods of three months with blinded randomisation and cross-over, the bi-ventricular pacing mode showed its superiority to the inactive mode concerning all study endpoints, for example with an improvement of the functional capacity of 23% assessed by the 6-minutes-walk test. Thus the MUSTIC trial opens up the way for morbidity and mortality studies.

Aged↗

PubMed2001

Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay.

BACKGROUND: One third of patients with chronic heart failure have electrocardiographic evidence of a major intraventricular conduction delay, which may worsen left ventricular systolic dysfunction through asynchronous ventricular contraction. Uncontrolled studies suggest that multisite biventricular pacing improves hemodynamics and well-being by reducing ventricular asynchrony. We assessed the clinical efficacy and safety of this new therapy. METHODS: Sixty-seven patients with severe heart failure (New York Heart Association class III) due to chronic left ventricular systolic dysfunction, with normal sinus rhythm and a duration of the QRS interval of more than 150 msec, received transvenous atriobiventricular pacemakers (with leads in one atrium and each ventricle). This single-blind, randomized, controlled crossover study compared the responses of the patients during two periods: a three-month period of inactive pacing (ventricular inhibited pacing at a basic rate of 40 bpm) and a three-month period of active (atriobiventricular) pacing. The primary end point was the distance walked in six minutes; the secondary end points were the quality of life as measured by questionnaire, peak oxygen consumption, hospitalizations related to heart failure, the patients' treatment preference (active vs. inactive pacing), and the mortality rate. RESULTS: Nine patients were withdrawn from the study before randomization, and 10 failed to complete both study periods. Thus, 48 patients completed both phases of the study. The mean distance walked in six minutes was 22 percent greater with active pacing (399+/-100 m vs. 326+/-134 m, P<0.001), the quality-of-life score improved by 32 percent (P<0.001), peak oxygen uptake increased by 8 percent (P<0.03), hospitalizations were decreased by two thirds (P<0.05), and active pacing was preferred by 85 percent of the patients (P<0.001). CONCLUSIONS: Although it is technically complex, atriobiventricular pacing significantly improves exercise tolerance and quality of life in patients with chronic heart failure and intraventricular conduction delay.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1992

Enhanced O2 transportation during cardiopulmonary bypass in piglets by the use of inositol hexaphosphate loaded red blood cells.

A continuous lysing and resealing of erythrocytes permitted internalization of inositol hexaphosphate (IHP), a strong allosteric effector of Hb, leading to significant rightward shifts of the HbO2 dissociation curve. Twelve piglets were put on cardiopulmonary bypass (CPB) with the heart beating, cooled to 25 degrees C then rewarmed to 37 degrees C before weaning off CPB. AoP, LV pressure, PAP, and cardiac output (CO) were monitored. Blood samples were taken before CPB, at 25 degrees C, at 30 degrees C, at 37 degrees C and after CPB for assessment of blood gases, arterio-venous difference in O2 content, lactates, P50 (partial pressure of O2 at 50% Hb saturation), and ionogram. Control group I included five pigs where the CPB circuit was primed with Ringer's lactate solution and porcine blood. In group II (n = 5), priming was done with Ringer's lactate solution and IHP loaded erythrocytes. P50 was significantly higher during CPB than before surgery in group II (20%), but not in group I (1%). There was a significant increase in VO2 in group II (6.02 ml/min) compared to group I (4.03 ml/min) (p less than 0.05) after CPB. Hemodynamics improved after CPB in group II (mean AoP 42 mmHg and syst LVP 70 mmHg) compared to group I (AoP 25 mmHg and syst LVP 22.5 mmHg). These preliminary results show that O2 transportation at the end of CPB is enhanced and myocardial function is improved in piglets with the use of IHP erythrocytes.

Animals↗

PubMed1990

Several aspects of red blood cell engineering: potential therapeutic applications.

Erythrocytes can be used to entrap drugs, enzymes or other molecules with active properties, with various encapsulation procedures. The method of internalization we are using includes an hypotonic dialysis step. Carrier erythrocytes survival depends on the dialysis process and the carried molecule. Research has led us to perform preclinical trials on animals for several drugs and enzyme therapies and for the improvement of oxyphoric capacity of erythrocytes. There exist many potential clinical applications for each kind of internalized molecules.

Animals↗

PubMed1989

Modification of partial pressure of oxygen (P50) in mammalian red blood cells by incorporation of an allosteric effector of hemoglobin.

Internalization of inositol hexaphosphate (IHP) in mammalian red blood cells (RBC) produces a modification of the hemoglobin-oxygen affinity, leading to a rightward shift of the dissociation curve. The process of incorporation, based on an osmotic shock, has been tested on RBC of different species. Two dialysis protocols have been defined to transform RBC, the first one for small volumes in a cellulose bag and the other for larger volumes using a commercially available dialysis device. Different optimal conditions must be used for each species. Most of the cellular characteristics of the transformed RBC having encapsulated IHP are similar to those of native cells. For several species, such modified RBC could be reinfused and used for physiological studies.

Allosteric Regulation↗

PubMed1985

[Diagnostic and therapeutic use of human anti-D (Rho) monoclonal antibodies. Evaluation and perspectives].

Human monoclonal antibodies will be essential in medicine. They are valuable tools for biological diagnosis and therapeutics. Our model, human monoclonal antibodies directed against the Rhesus D antigen can be used for the determination of the Rhesus D phenotype and for the suppression of Rh(D) immunisation in women. These new products require new procedures of preparation, new regulations for the quality controls, which will be discussed in this paper.

Animals↗