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Biomedical subjects

G Motte

Publications and source records attributed to G Motte.

At least 19 recordsLinked to original sources
PubMed2002

Hypertension in renal transplantation: donor and recipient risk factors.

AIMS: To determine the respective roles of donor and recipient factors in the subsequent development of hypertension after renal transplantation. PATIENTS AND METHODS: All the patients transplanted between January 1990 and December 1999 who still had a functioning graft 1 year post-transplant (n = 321) were retrospectively studied. Blood pressure was assessed at 1 year post-transplant. Hypertension was defined as a systolic BP > or equal 140 mmHg or diastolic BP > or equal 90 mmHg, or use of antihypertensive medication. Relevant donor and recipient characteristics were recorded. RESULTS: Two-hundred-and-sixty-three patients (82%) were hypertensive. In multivariate analysis, pretransplant hypertension (RR, 1.74, 95% CI, 1.07 to 2.87), anticalcineurin use (RR, 2.59, 95% CI, 1.13 to 5.92), urinary protein excretion (RR, 1.84, 95% CI, 1.06 to 3.18), BMI (RR, 1.08, 95% CI, 1.01 to 1.16), donor age (RR, 1.28,95% CI, 1.05 to 1.59, for each 10-year increase in donor age) and donor aortorenal atheroma (OR, 2.34; 95% CI, 1.24 to 4.46) were associated with hypertension. Among patients under calcineurin inhibitors, those receiving cyclosporine were more prone to have hypertension than those receiving tacrolimus (88.7% vs 78%; p = 0.04). CONCLUSION: Both recipient and donor factors contribute to hypertension in RTR.

Adult↗
PubMed2001

Vitamin E-coated dialyzer reduces oxidative stress in hemodialysis patients.

The high incidence of cardiovascular disease in hemodialyzed (HD) patients is well established and oxidative stress has been involved in this phenomenon. The aim of our study was to evaluate if a vitamin E-coated dialyzer could offer protection to HD patients against oxidative stress. Sixteen HD patients were successively assessed for one month (i) on a high biocompatible synthetic dialyzer (AN) and (ii) on a vitamin E-coated dialyzer (VE). Blood samples were taken before and after the dialysis session at the end of each treatment period. HD session conducted with the AN dialyzer was responsible for acute oxidative stress, significantly assessed after HD by a decreased plasma vitamin C level and an increased ascorbyl free radical (AFR)/vitamin C ratio used as an index of oxidative stress. Plasma elastase activity, reflecting neutrophil activation, was also increased; soluble P-selectin, reflecting platelet activation, did not show any variation. The use of the VE dialyzer was associated with a less extended oxidative stress compared with the AN membrane: basal vitamin C level was higher, and after the HD session AFR/vitamin C ratio and elastase activity were not significantly increased. Plasma vitamin E levels were not affected. Our study demonstrates that HD is associated with oxidative stress, which can be partially prevented by the use of a vitamin E-coated dialyzer. Our data suggest that this dialyzer may exert a site-specific scavenging effect on free radical species in synergy with a reduced activation of neutrophils.

Aged↗
PubMed2001

Determinants of mean arterial pressure and pulse pressure in chronic haemodialysis patients.

Hypertension is highly prevalent in the dialysis population, and has been implicated in the pathogenesis of the observed excess of cardiovascular morbidity and mortality in these patients. Nevertheless, there are no reports on the clinical and biochemical determinants of both pulse pressure (PP) and mean arterial pressure (MAP) in dialysis populations. A total of 541 haemodialysed patients from 11 dialysis centres were included in the study. The demographic, clinical, and biological characteristics were recorded. Both pre- and post- dialytic blood pressures (systolic and diastolic) were measured. PP and MAP were calculated. Mean predialytic PP was 67 +/- 17 mm Hg and significantly decreased after dialysis (60 +/- 18 mm Hg; P < 0.0001). In multivariate analysis, a 10 mm Hg increase in PP was positively associated with age (RR, 2.01; 95% CI, 1.35-5.01, for a 10-year increase in age), diabetes mellitus (RR, 1.08; 95% CI, 1.04-1.14), interdialytic weight gain (IWG) (RR, 1.84; 95% CI, 1.07-3.18, for 1% increase in IWG), and current smoking (RR, 2.59; 95% CI, 1.13-5.92) and negatively with Hb concentration (RR, 0.92; 95% CI, 0.84-0.99, for a 1 g/100 ml in Hb). Mean predialytic MAP was 98 +/- 15 mm Hg and significantly decreased after dialysis (91 +/- 16 mm Hg; P < 0.0001). In multivariate analysis, a 10 mm Hg increase in MAP was positively associated with parathyroid hormone (PTH) (RR, 1.32; 95% CI, 1.15-1.6, for 50 ng/ml in PTH), erythropoietin (EPO) treatment (RR, 1.09; 95% CI, 1.03-1.16), and current smoking (RR, 1.87; 95% CI, 1.39-2.41). PP and MAP are associated with different clinical parameters. Most of these factors are potentially reversible. Smoking cessation, correction of anaemia and limitation of IWG should be important challenges for physicians in care of dialysis patients.

Age Factors↗
PubMed1999

Polycystic kidney disease as a risk factor for post-transplant diabetes mellitus.

BACKGROUND: Insulin resistance with compensatory hyperinsulinaemia has been reported in adult polycystic kidney disease (APKD) patients. Diabetes mellitus is a common complication following transplantation and previous studies have demonstrated that inadequate insulin secretion was a prerequisite for the development of post-transplant diabetes mellitus (PTDM). We conducted a retrospective study to determine whether APKD is a risk factor for PTDM. METHODS: Twenty-six consecutive patients transplanted because of end-stage renal disease due to APKD were studied. A control patient matched for age, gender, immunosuppressive therapy and transplant year was selected for each APKD patient. PTDM was defined by fasting glycaemia exceeding 7.8 mmol/l and the need for insulin or oral antidiabetic therapy. RESULTS: Age, renal function, immunosuppressive regimen, number of acute rejection, cumulative dose of steroids and haemodialysis duration before transplantation were similar in both groups. PTDM occured in 10 APKD patients and four controls (34.6% vs 15.3%; P < 0.005). Among diabetic patients, six APKD patients and two controls required insulin therapy (60% vs 50%; P = n.s.). Diabetic patients were significantly older (55.8 +/- 7 years vs 50.2 +/- 11 years; P < 0.05). CONCLUSION: Although retrospective, this study suggests that APKD confers an increased risk of PTDM.

Adult↗
PubMed1995

Evaluation of radionuclide angiography in diagnosis of arrhythmogenic right ventricular cardiomyopathy.

OBJECTIVES: The accuracy of Fourier analysis of radionuclide angiography for the diagnosis of arrhythmogenic right ventricular cardiomyopathy was assessed versus X-ray right ventricular angiography. BACKGROUND: In patients with recurrent right ventricular tachycardia, the diagnosis of arrhythmogenic right ventricular cardiomyopathy is based on the presence of right ventricular wall motion abnormalities on conventional X-ray angiography without evidence of other heart disease. METHODS: X-ray and radionuclide angiography were prospectively compared in 73 patients with ventricular tachycardia. We analyzed the presence of a right ventricular enlargement, global hypokinesia and segmental wall motion abnormalities, using visual analysis for both techniques and Fourier analysis for radionuclide angiography. Disease was noted as absent or present and as diffuse or localized. The interobserver reproducibility of both techniques for the diagnosis of right ventricular wall motion abnormalities was tested in 27 randomly selected patients. RESULTS: According to X-ray angiography, 53 patients were considered to have arrhythmogenic right ventricular cardiomyopathy (22 diffuse, 31 localized forms) and 20 patients a normal right ventricle. The sensitivity of radionuclide angiography was 94.3%, specificity 90% and positive and negative predictive values 96% and 85.7%, respectively. Agreement for the location of the wall motion abnormalities was 60% for the apex, 76% for the outflow tract, 82% for the inferior wall and 74% for the free wall. The diagnostic interobserver reproducibility of X-ray and radionuclide angiography was 74% and 96.2%, respectively. CONCLUSIONS: In a selected cohort, Fourier analysis of radionuclide angiography is an accurate and reproducible tool for the diagnosis of arrhythmogenic right ventricular cardiomyopathy.

Adult↗
PubMed1989

[Clinical electrophysiologic properties of magnesium and correlations with its anti-arrhythmia efficacy in acquired torsade de pointes].

Recently, intravenous administration of low doses of magnesium has proved remarkably effective in the treatment of acquired torsade de pointe, but its electrophysiologic effects remain poorly understood. Three clinical cases are reported in three distinct situations (quinidine treatment, hypokalemia, bradycardia with complete atrioventricular block). These cases confirm the efficacy of magnesium, which acts without notable modification of ventricular cycles or the duration of repolarization. In ten patients undergoing intracavitary exploration, the electrophysiologic parameters were analyzed before and after injection of magnesium sulfate (35 mg/kg). Only three parameters were significantly altered; the corrected sinusal recovery time (increase from 245 +/- 92 ms to 296 +/- 96 ms), the effective nodal refractory period (increase from 333 +/- 98 ms to 346 +/- 93 ms), and the Wenckebache period (decrease from 157 +/- 28/min to 144 +/- 21/min). No changes were noted in other parameters, notably ventricular (QT interval, QRS duration, HV interval, and effective ventricular refractory period). The arrhythmic action on the ventricle is therefore remarkable and is not accompanied by patent electrophysiologic effects. The efficacy of magnesium in torsade de pointe may suggest action on calcium currents.

Aged↗
PubMed1989

Reduced sensitivity of human platelets to PAF-acether following ticlopidine intake.

We investigated in 9 patients the effect of a 7-day treatment by Ticlopidine (250 mg b.i.d.) on washed platelets activation by PAF-acether in comparison with adenosine 5'-diphosphate (ADP) and arachidonic acid (AA). Aggregations induced by ADP were totally suppressed upon drug administration. AA-induced aggregations were partly but significantly inhibited (p less than 0.05). Responses of platelets to PAF-acether before treatment differed from patient to patient. A paired Student's test and a two-way analysis of variance showed a significant inhibitory effect of Ticlopidine treatment on PAF-acether-induced aggregation. The inhibitory effect of Ticlopidine or its metabolite(s) was evidenced after platelet washing procedure, suggesting a persistent effect of this drug on platelet after administration of the drug has been stopped.

Adenosine Diphosphate↗
PubMed1988

Non-invasive measurement of pulmonary arterial pressure: II. A radionuclide method.

Pulmonary artery pulse pressure (PP) and diastolic pressure (Pd) may be obtained by applying a haemodynamic model of blood flow kinetics and wall mechanics to the pulmonary artery: Pp = rho(ws/(Ss/Sd-1))2log(Ss/Sd)-1/2 rho w2s Pd = (Sd/Ss)1/2Pp where rho is blood density, ws is peak ejection velocity, and Ss and Sd are peak maximal and end diastolic cross-sectional areas of the main pulmonary artery. The different parameters of the equations were measured from radionuclide first pass and equilibrium studies. Radionuclide first pass studies were performed in 24 patients with intravenous injection of 20 mCi of 99Tcm red blood cells with a gamma camera in a 20 degrees right anterior oblique position: data were collected in list mode, i.e. a continuous sequence of spatial and temporal coordinates of each photon. Pulmonary arterial pressure was recorded simultaneously with a microtip catheter during the first pass study. Gated first pass images of the right side of the heart were reconstructed, regions of interest drawn over the right ventricle and the main pulmonary artery (MPA) and time-activity curves generated. Peak systolic (Cs) and end diastolic (Cd) counts obtained from the MPA curve were proportional to the cross sections Ss and Sd of the MPA and Ss/Sd = Cs/Cd. The diameter (D) of the pulmonary artery was calculated as the distance between the two zeros of the second derivative of a cross-sectional profile. The averaged cross-sectional area was S = pi D2/4. ECG gated blood pool studies were performed in a LAO 40 degrees position when the tracer was at equilibrium; they were processed automatically and the right ventricular end diastolic counts (EDC) converted into volume (EDV) using an aortic volume/count ratio. Right ventricular peak ejection rate (PER) was obtained from the RV time-activity curve and the instantaneous peak ejection velocity was calculated, ws = PER X EDV/S X EDC. PP and Pd were calculated in mmHg and the radionuclide method yielded pressure values that correlated reasonably with catheterisation values: PP(rad) = 0.99 PP(cath)-0.55, r = 0.84 and Pd(rad) = 0.67 Pd(cath) + 4.91, r = 0.74. We conclude that radionuclide techniques can provide a non-invasive method based on a haemodynamic model for measuring pulmonary arterial pressure.

Adult↗
PubMed1988

[Sotalol-induced torsades de pointe in the conscious dog with atrioventricular block. Role of hypokalemia].

Sotalol is a beta-blocking agent endowed with class III electrophysiological properties. It has proved clinically effective in the treatment of arrhythmia, but episodes of torsades de pointe have been observed, particularly (though not exclusively) in the presence of hypokalaemia. The effect of sotalol with or without hypokalaemia was studied on a recently developed model for experimental torsades de pointe. Conscious dogs with complete atrioventricular block (ventricular cycle RR = 1530 +/- 170 ms) and provided with permanent atrial and ventricular epicardial electrodes were given sotalol intravenously either as a 4.5 mg/kg bolus injection or as a 1.5 mg/kg/h infusion. Group I dogs (n = 8) had normal blood potassium levels (4.3 +/- 0.1 mEq/1); following sotalol (plasma concentration 3.7 +/- 0.2 micrograms/ml) the ventricular rhythm was electrically driven to 25/min (RR = 240 ms) and QT was increased by 68 +/- 11 ms; torsades de pointe occurred in 5/8 animals (62 p. 100). Group II dogs (n = 6) had diuretic-induced hypokalaemia (2.6 +/- 0.1 mEq/1); following sotalol (plasma concentrations 3.8 +/- 0.3 micrograms/ml) the ventricular rhythm also depended on an external pacemaker to reach 25/min (in all but 1 dog) and QT increased by 46 +/- 11 ms; torsades de pointes were obtained in 5/6 animals (83 p. 100). These torsades de pointe were prevented in every case by rapid ventricular pacing (100-120/min). Thus, the pro-arrhythmic effects of sotalol were very frequent on this experimental model, but hypokalaemia was not necessary for torsades de pointe to occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Phase mapping of radionuclide gated biventriculograms in patients with sustained ventricular tachycardia or Wolff-Parkinson-White syndrome.

Accuracy of Fourier phase mapping of radionuclide gated biventriculograms in detecting the origin of abnormal ventricular activation was studied during ventricular tachycardia or preexcitation. Group I included six patients suffering from clinical recurrent VT; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right ventricular pacing, and induced sustained VT-Group II included seven patients with Wolff-Parkinson-White syndrome and recurrent paroxysmal tachycardia; 3 gated blood pool studies were acquired for each patient: during sinus rhythm, right atrial pacing and orthodromic reciprocating tachycardia. Each acquisition lasted 5 min, in 30 degrees-40 degrees left anterior oblique projection. In Group I, the Fourier phase mapping was consistent with QRS morphology and axis during VT (5/6), except in one patient with LV aneurysm and LBBB electrical pattern during VT. Origin of VT on phase mapping was located in the right ventricle (n = 2) or in left ventricle (n = 4), at the border of wall motion abnormalities each time they existed (5/6). In Group II, the phase advance correlated with the location of the accessory pathway determined by ECG and endocardial mapping (n = 6) and per-operative epicardial mapping (n = 1). Discrimination between anterior and posterior localisation of paraseptal pathways and location of intermittent preexcitation was not possible. We conclude that Fourier phase mapping is an accurate method for locating the origin of VT and determining its etiology. It can help locate the site of ventricular preexcitation in patients with only one accessory pathway; its accuracy in locating multiple accessory pathways remains unknown.

Adult↗
PubMed1986

Triple antegrade nodal pathway in a patient with supraventricular paroxysmal tachycardia.

A 69-year-old patient is described in whom programmed atrial extrastimulus testing revealed dual discontinuity of atrioventricular nodal conduction suggesting a triple antegrade nodal pathway. In this patient, programmed right ventricular pacing initiated two types of tachycardia due to intranodal reciprocating rhythms. In both cases, antegrade conduction occurred via the slow nodal pathway, and retrograde conduction by the fast and intermediate pathways, respectively. During ventricular extrastimulus testing, a single echo beat was elicited via a third circuit: the intermediate nodal pathway in a retrograde direction, and the fast pathway in an antegrade direction.

Aged↗
PubMed1985

Changes in left ventricular performance during chronic pressure or volume overload: importance of physical properties of the arterial system.

The present study was aimed at evaluation of changes in systolic and diastolic left ventricular function during chronic pressure of volume overload, in comparison with normal subjects. Sixty-two patients were included: group 1 was composed of 25 normal subjects, group 2 was composed of 20 subjects with essential hypertension, and group 3 was composed of 17 subjects with aortic regurgitation without congestive heart failure. Cardiac output, aortic and left ventricular pressures (micromanometers), ventricular volume and ascending aortic radius (cineangiography), ejection fraction (EF), mean velocity of fiber shortening (VCF), ventricular mass (m), and the ratio m/EDV (EDV, end diastolic volume) were determined. Also measured were maxima for end systolic pressure (ESP), end systolic stress (ESS), and end systolic volume (ESV) and radius (ESR), as well as the modulus of left ventricular chamber and muscle stiffness (method of Gaash et al.) (1) and characteristic impedance of the ascending aorta (Zc). In hypertensive patients, m and m/EDV were increased, as was the ESP/ESV ratio, whereas EF and VCF were not modified and the ESS/ESR was normal or sometimes decreased. The systolic "pump" function thus appeared to be increased, whereas the muscle function appeared normal or decreased. The moduli of left ventricular chamber stiffness and muscle stiffness were increased. Zc was increased because of a greater pulse wave velocity, although aortic radius was larger. A close relationship was found between Zc and the ratio m/EDV. In patients with aortic regurgitation, the increased left ventricular mass was closely related to the regurgitant fraction (RF). The m/EDV ratio was normal. EF was unmodified and VCF and the ESP/ESV ratio were decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗