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Biomedical subjects

P Maury

Publications and source records attributed to P Maury.

At least 19 recordsLinked to original sources
PubMed2006

Genetic variability for physiological traits under drought conditions and differential expression of water stress-associated genes in sunflower (Helianthus annuus L.).

Genotypic variation for water status and gas exchange parameters under different water treatments (well-watered and water-stressed plants before and after rehydration) were investigated in a population of recombinant inbred lines (RILs) of sunflower (Helianthus annuus L.). Afterwards, four RILs and parental lines presenting contrasting responses to dehydration and rehydration were selected to determine the differential expression of four water-stress associated genes: aquaporin, dehydrin, leafy cotyledon1-like protein and fructose-1,6 bisphosphatase. Water stress revealed a high genetic variability for water status and gas exchange parameters when compared with well-watered genotypes. Genetic gain when selected RILs were compared with the best parent was significant for most traits due to transgressive segregation. QTL mapping and graphical genotyping showed that RILs carrying different genomic regions for some QTLs presented also physiological different characteristics as well as gene expression patterns. The expression level of aquaporin genes in leaves of four RILs and their parents was down regulated by water stress and was associated with relative water content (RWC). Down-regulation was also associated with genomic regions having alleles with negative effects on plant water status. The level of dehydrin transcripts increased in leaves of all studied RILs in response to water stress. Transcript accumulations of dehydrin and leafy cotyledon1-like genes, likely involved in protective tolerance processes, were not correlated directly with plant water status or QTL effects. Down-regulation of fructose-1,6 bisphosphatase was observed under water stress. Net photosynthesis rate (P(n)) and the fructose-1,6 bisphosphatase gene expression levels were associated mainly after rehydration. This phenomenon indicates an association between physiological response to water stress and differential expression of water-stress related genes.

Dehydration↗
PubMed2006

[Cardiac asystole during acute anterior myocardial infarction: a consequence of endocardiac reflexes].

The authors report a case of paroxysmal, complete atrioventricular block during an anterior acute myocardial infarction, leading to asystolia. The different possible physiopathological mechanisms are discussed, suggesting a paroxysmal nodal conduction defect, secondary to transient parasympathetic stimulation, triggered by a Bezold-Jarish type of cardiac reflex. This reflex is frequently involved in various pathologic situations or diagnostic procedures, usual in cardiology. Although it is frequently observed in inferior myocardial infarction, it can occur during an anterior acute myocardial infarction.

Aged↗
PubMed2005

Electrical storms in Brugada syndrome: review of pharmacologic and ablative therapeutic options.

Electrical storm occurring in a patient with the Brugada syndrome is an exceptional but malignant and potentially lethal event. Efficient therapeutic solutions should be known and urgently applied because of the inability of usual antiarrhythmic means in preventing multiple recurrences of ventricular arrhythmias. Isoproterenol should be immediately infused while oral quinidine should be further administrated when isoproterenol is not effective. In case of failure of these therapeutic options, ablation of the triggering ventricular ectopies should be attempted.

Journal Article↗
PubMed2005

[Characterization of premature ventricular contraction initiating ventricular fibrillation].

UNLABELLED: The aim of this study is to characterize the electrocardiographic features of premature ventricular contractions (PVC) from different anatomical region that trigger ventricular fibrillation (VF). METHODS AND RESULTS: 36 consecutives patients (20 males, 42+/-14 yrs) undergoing VF ablation from 7 centres were studied (22 with idiopathic VF, 4 associated with a long QT syndrome, 3 with Brugada syndrome, 4 with ischaemic cardiomyopathy and 3 associated with other substrate). Mapping of these PVC showed 2 different origins, which were then confirmed by ablation: right ventricular outflow tract (RVOT) (22%) and peripheral Purkinje network (81%). One patient had PVC from both origins (Brugada). RVOT PVC were frequent but had triggered only 5+/-5 episodes of VF for 26+/-33 months. Purkinje PVC were more likely to be present during electrical storm with 18+/-28 episodes of VF for 33+/-45 months. Right Purkinje PVC have a left bundle branch block with superior axis morphology whereas left Purkinje ones have a right bundle branch block. The axis of activation showed variation from inferior to superior depending on the area of origin from the Purkinje network and the exit site to the myocardium. However Purkinje PVC were characterized by short QRS duration (126+/-18 vs 145+/-13ms for RVOT PVC; p=0.05). In addition the coupling interval was significantly shorter compared to RVOT PVC (292+/-45 vs 358+/-37ms respectively; p=0.005). CONCLUSION: PVC initiating VF demonstrate specific electrocardiographic features that facilitate determination of their origin. Ablation of these typical PVC is feasible in order to reduce ICD shock.

Adult↗
PubMed2005

[Prescriptions following acute coronary syndrome].

Each year in France, 150,000 to 180,000 new patients are the subject of prescriptions following acute coronary syndrome with or without ST segment elevation. There are two targets of the treatment, atherosclerosis, a diffuse, evolving trouble which, in this situation, is coming out of an unstable phase, and the myocardium, which has often been revascularised and has suffered deterioration of its contractile and electrophysiological characteristics to a greater or lesser extent. Prescriptions, based on proven factors and always centred on hygiene and dietary advice and the use of a combination of statins and aspirin, are adapted to suit the atherosclerotic and myocardial risk assessed for the individual patient. The prescription starts off the secondary preventive phase. It marks the first stage of the follow up, which is inevitable though of variable duration, for a disease which may evolve. It is the first step in the accompaniment of an attentive, informed patient whose confidence has been restored and who must now avoid falling into the double trap of not taking the treatment sufficiently seriously or of obsessively over-reacting.

Angina, Unstable↗
PubMed2005

[Ablation of ventricular extra-systole in the left Valsalva sinus. A case report].

We report the case of a patient presenting with unrelenting isolated or repetitive monomorphic ventricular extra-systoles, with left block and right axis deviation, which appeared to arise from the right ventricular chamber, but for which ablation was finally performed in the left Valsalva sinus. The ECG and endocavity electro-physiological features which led us to suspect this atypical, although not exceptional, situation are reported, as well as the techniques for ablation available in this case.

Adult↗
PubMed2004

Electrical storm in Brugada syndrome successfully treated using isoprenaline.

A case of an electrical storm occurring in a patient implanted with a cardioverter-defibrillator for Brugada syndrome is reported. Recurrent ventricular fibrillation was initiated by short-coupled isolated monomorphic ventricular premature beats probably originating from the right ventricular outflow tract, associated with a manifest electrocardiographic pattern of Brugada syndrome. Infusion of atropine accelerated the heart rate but did not prevent ventricular fibrillation, however, low doses of isoprenaline quickly obviated any recurrence of ventricular fibrillation. This was associated with the disappearance of the short-coupled premature beats together with a normalization of the electrocardiographic pattern. Possible mechanisms are discussed according to the accepted pathophysiological hypothesis.

Adrenergic beta-Agonists↗
PubMed2004

[Slow ventricular tachycardia presenting in the antenatal period].

The authors report two cases of slow ventricular tachycardia presenting in the antenatal period. One foetus had anasarca at 38 weeks' gestation. After birth, improved myocardial function contributed to the rapid resorption of the effusions. The other case was well tolerated in the foetal and neonatal periods. In both cases, Holter ECG recorded an intermittent ventricular arrhythmia with salvos of sustained ventricular tachycardia with a maximum rate of 185/min, only 10% higher than the underlying sinus rhythm, disappearing on acceleration of the sinus rhythm. The aetiological investigation was negative. Therapeutic abstention was supported by the spontaneously favourable outcome after 3 and 5 months. Slow ventricular tachycardia or accelerated idioventricular rhythms are usually considered to be benign but the case with foetal anasarca suggests that they should be carefully followed up in the neonatal period. In the absence of a consensus on management, therapeutic abstention implies regular cardiological examination until the arrhythmia has disappeared.

Female↗
PubMed2003

Distinction between atrioventricular reciprocating tachycardia and atrioventricular node re-entrant tachycardia in the adult population based on P wave location; should we reconsider the value of some ECG criteria according to gender and age?

AIMS: Distinction between atrioventricular node re-entrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT) is sometimes difficult using location of retrograde P waves on ECG. METHODS: P wave location was retrospectively determined in 137 anterior slow-fast AVNRT (85%) and 26 orthodromic AVRT (15%) with narrow QRS occurring in 161 successive patients without pre-excitation. Mechanism of arrhythmia was assessed by electrophysiological study and confirmed by the efficacy of radiofrequency ablation. P waves were classified as invisible, visible after the QRS, or as R' in V(1) and/or S in II. Correlations with arrhythmia mechanism were made according to gender and age (>or= or <65 years old). RESULTS: Mechanism was related to gender but not to age, with a higher proportion of AVNRT in women (89/97, 91%) than in men (48/66, 72%) (P=0.001). AVRT presented with visible P waves in 26/26 cases (100%) while AVNRT presented with invisible P waves in 36/137 (27%), R'V(1)/SII in 79/137 (57%) and visible P waves in 22/137 (16%). P wave location during AVNRT was related to age but not to gender, with a higher proportion of AVNRT with visible P waves in elderly than in younger patients: 8/27 (29%) vs 14/110 (12%) (P=0.03). Visible P wave during AVNRT was mainly caused by a delay in nodal retrograde conduction in 17/22 patients (77%). Mechanism of tachycardia with visible P waves was related to gender (AVNRT in 14/22 women (64%), AVRT in 18/26 men (70%), P =0.02) and to age, although non-significantly (AVNRT in 8/13 (62%) old vs 14/35 (40%) young patients, P=0.18). A visible P wave was predictive of AVNRT in 25% and in 60% of the men and women younger than 65 years old, and in 50% and in 71% of older men and women respectively (P=0.08 - borderline significance). CONCLUSIONS: Correct distinction between anterior slow-fast AVNRT and orthodromic AVRT can be reliably made regardless of gender or age in case of R'V(1)/SII or invisible P wave. AVRT as the expected mechanism should be reconsidered in the case of visible P waves in the elderly and in the female gender in the absence of pre-excitation.

Age Factors↗
PubMed2002

[Imaging of complications following hip arthroplasty].

Acute complications include fractures and prosthesis dislocations. Most chronic complications involve mechanical or septic loosening and aggressive granulomatosis. Greater trochanteric pseudarthrosis, periprosthetic soft tissue ossifications or prosthesis conflict with the psoas muscle can also be responsible for groin pain. Most complications are detected with serial plain radiographs, but additional imaging techniques including CT scan and scintigraphy are sometimes necessary for pretreatment diagnosis. Pain generally indicates a complication but aggressive granulomatosis can be asymptomatic, thus warranting systematic annual plain radiographic control.

Acute Disease↗
PubMed2002

[Continuous nodal reciprocal rhythm and Steinert's disease: treatment by double chamber stimulation. A case report].

We report a case of continuous supraventricular tachycardia in a patient affected by Steinert's myotonic dystrophy. The investigation of this tachycardia showed that there was a "slow-fast" common nodal re-entry, rendered continuous by the existence of significant conduction defects in the fast pathway and the slow anterograde pathway. Implantation of a double chamber cardiac stimulator, necessary for conduction defects present in the basal state in this patient allowed, with the evolution of the conduction defects, the complete eradication of reciprocal rhythm entry, without resorting to ablation.

Electroencephalography↗
PubMed2001

[Implantable defibrillator. Update].

The implantable cardioverter-defibrillator is a device able to detect and efficiently treat life-threatening ventricular arrhythmias. Its decisive accomplishment in reducing sudden cardiac death and total cardiac mortality, opposed to the insufficient reliability of the traditional therapies explains its present ascendancy. In this review, the working principles and the implant techniques are developed, as well as the complications and the usual problems which could be encountered in implanted patients. Finally, the current indications are discussed in the light of recent clinical trials.

Arrhythmias, Cardiac↗
PubMed2000

[Paroxysmal atrioventricular block during coronary revascularization with ultrasound. A case report].

The authors report the case of advanced atrioventricular block during a procedure of right coronary revascularisation with ultrasound. The different possible physiopathological mechanisms are discussed. Although no formal conclusions can be drawn, certain features suggest a paroxysmal nodal conduction defect secondary to transient parasympathetic stimulation by the ultrasound, a stimulation triggered by a Bezold-Jarish type of cardiac reflex or by direct local excitation of vagal fibres of the atrioventricular node.

Coronary Disease↗
PubMed1999

Association between nonreentrant supraventricular tachycardia and atrioventricular node reentrant tachycardia: a presentation of dual AV node physiology.

Persistent simultaneous conduction of P waves over a fast and a slow nodal pathway defines the nonreentrant type of supraventricular tachycardia, usually not associated with reciprocating movements. We report a unique association between this uncommon tachycardia and a usual AV nodal reentrant tachycardia, made possible by the existence of three different nodal pathways.

Atrioventricular Node↗
PubMed1999

[Severe flecainide acetate poisoning. Apropos of a case].

Poisoning with flecainide acetate is rare and associated with a high mortality. This usually occurs after massive ingestion but can also be observed during therapeutic overdose in patients with renal failure or with amiodarone therapy. The prognostic depends on the haemodynamic and rhythmic effects of the overdose one sign of which is widening of the QRS complexes. Major sodium bicarbonate or lactate infusion is the generally prescribed treatment. The authors report one case of a patient with renal failure on amiodarone who survived a severe flecainide acetate overdose.

Aged↗