Patients avec syndrome de Brugada et défibrillateur implanté : suivi clinique

Introduction :¦Le syndrome de Brugada (SB) se définit par une élévation du segment ST dans les dérivations précordiales droites (V1-V3) associée à une incidence élevée de mort subite par arythmies chez des patients sans cardiopathie structurelle. La prévention de la mort subite repose sur la pose d'un défibrillateur automatique implantable (DAI).¦Matériel et méthode :¦Cette étude est une analyse rétrospective de tous les patients avec SB implantés d'un DAI au CHUV entre 1998 et 2010. Le profil des patients, les complications, ainsi que les thérapies appropriées et inappropriées délivrées par le défibrillateur ont été évaluées. Une thérapie appropriée est définie par l'action appropriée du DAI (choc ou stimulation anti-tachycardie = ATP) en réponse à une TV ou une FV correctement détectée. La thérapie inappropriée est définie comme une thérapie délivrée par l'appareil en l'absence d'une arythmie ventriculaire.¦Résultats :¦Durant la période étudiée (01.01.1998 - 31.12.2010) nous avons collecté au total 23 patients soit 19 hommes (83%) et 4 femmes (17%) âgés de 12 à 60 ans (41 13 ans). Le rapport hommes/femmes est de 4.75. Le suivi quant à lui porte sur 21 patients: un patient, après échec de primo-implantation au CHUV, a été implanté d'un défibrillateur dans un autre canton et un second patient a été perdu de vue entre l'implantation et le premier contrôle prévu. Le suivi moyen des 21 patients restants est de 8432 mois (37-149 mois, médiane : 78 mois). Il y a eu au total 45 thérapies délivrées : 12 appropriées (8 chocs; 4 ATP) et 33 inappropriées. 18% des patients ont eu ≥ 1 thérapie appropriée alors que 43% ont eu ≥ 1 choc inapproprié. 14 des 23 patients (61%) ont eu ≥ 1 complication (9 avec chocs inappropriés, 7 avec complications opératoires après primo-implantations ou ré-interventions, 6 avec dysfonction de sonde ventriculaire et 1 avec explantation).¦Conclusion :¦Le profil de ce petit collectif de patients avec SB implantés d'un DAI au CHUV est comparable à celui décrit dans la littérature. Durant un suivi moyen de 7 ans après la primo-implantation, l'incidence d'arythmies ventriculaires malignes est faible, avec un taux annuel de 2.6%. Le taux de complication est quant à lui élevé (8.7%/an). Près des trois-quarts des thérapies délivrées par le DAI sont inappropriées et les patients avec thérapies inappropriées sont 2.4x plus fréquents que les patients avec thérapies appropriées

Reference values and sex differences in absolute and relative kidney size. A Swiss autopsy study.

Men have larger kidneys than women, but it is unclear whether gender remains an independent predictor of kidney size (expressed as weight or length) after correction for body size. We analysed autopsy data to assess whether relative renal length and weight (e.g. corrected for body weight, height or body surface area (BSA)) are also larger in men. Assuming that kidney size is associated with nephron number, opposite findings could partly explain why women are less prone to the development and progression of chronic kidney disease than men. All forensic autopsies performed between 2009 and 2015 at the local university hospital of Geneva in individuals of European descent aged ≥18 years without a known history of diabetes and/or kidney disease were examined. Individuals with putrefied or severely injured bodies were excluded. Relative renal weight and length were respectively defined as renal weight divided by body weight or BSA and renal length divided by body height or BSA. A total of 635 autopsies (68.7% men) were included in the analysis. Left kidneys were on average 8 g heavier and 2 mm longer than right kidneys (both: p < 0.05). Absolute renal weight (165 ± 40 vs 122 ± 29 g) and length (12.0 ± 1.3 vs 11.4 ± 1.1 cm) were higher in men. Relative renal weight was also higher in men, but relative renal length was larger in women. In multivariable regression analysis, body height, body weight, the degree of blood congestion or depletion at autopsy and age were determinants of renal weight, whereas arterial hypertension and smoking were not. Percentile curves of renal weight and length according to sex and body height were constructed. Absolute and relative renal weights were both smaller in women. This is in line with recent studies stating that nephron numbers are also lower in women. Relative renal length was longer in women, suggesting that female kidneys have a more elongated shape. In comparison with older autopsy studies, renal weight appears to be stable over time

Contrast-Enhanced Ultrasound and Protein Shakes Are No Alternatives for Inulin Clearance and Meat to Assess Renal Functional Reserve in Humans.

The measurement of renal functional reserve (RFR) can unmask glomerular hyperfiltration in residual nephrons, but its determination is time-consuming. In this study, we assessed whether contrast-enhanced ultrasound (CEUS) is a valuable alternative to the gold standard inulin clearance and whether L-arginine or protein shakes lead to similar changes in glomerular filtration rate (GFR) as animal proteins in men and women. Changes in GFR and renal microperfusion were studied in 25 healthy subjects (8 men, 17 women) by simultaneously performing inulin clearance and CEUS (perfusion index, PI) before and 1 and 2 h after different protein loads (L-arginine, protein shake or meat). The Doppler parameters - renal resistive index (RRI) and pulsatility index (PuI) - were also measured. None of the oral protein loads induced significant changes in CEUS-assessed PI. Only meat increased inulin clearance (from 111.2 ± 16.0 to 149.8 ± 27.2 mL/min, p < 0.05) and mobilized RFR, while L-arginine decreased GFR (106.7 ± 45.3 to 86.3 ± 42.6 mL/min, p < 0.05). Protein shakes had a neutral effect. There were no correlations between changes in inulin clearance and PI. At Doppler, RRI and PuI increased after meat intake (from 0.647 ± 0.029 to 0.694 ± 0.050 a.u., p < 0.05 and from 1.130 ± 0.087 to 1.318 ± 0.163 a.u., p < 0.05, respectively), but their changes also did not correlate with changes in inulin clearance. Results were similar in both sexes. CEUS is not a valuable alternative for inulin clearance to measure RFR. Meat ingestion leads to modest changes in renal Doppler parameters and to glomerular hyperfiltration in both women and men, while protein shakes and L-arginine do not

Supplementary Material for: Contrast enhanced ultrasound and protein shakes are no alternatives for inulin clearance and meat to assess renal functional reserve in humans

Introduction: The measurement of renal functional reserve (RFR) can unmask glomerular hyperfiltration in residual nephrons but its determination is time-consuming. In this study we assessed whether contrast-enhanced ultrasound (CEUS) is a valuable alternative to the gold standard inulin-clearance, and whether L-arginine or protein shakes lead to similar changes in glomerular filtration rate (GFR) as animal proteins in men and women. Methods: Changes in GFR and renal microperfusion were studied in 25 healthy subjects (8 men, 17 women) by simultaneously performing inulin clearance and CEUS (perfusion index, PI) before and 1 and 2 hours after different protein loads (L-arginine, protein shake or meat). Doppler parameters - renal resistive index (RRI) and pulsatility index (PuI) - were also measured Results: None of the oral protein loads induced significant changes in CEUS-assessed PI. Only meat increased inulin clearance (from 111.2±16.0 to 149.8±27.2 ml/min, p<0.05) and mobilized RFR, while L-arginine decreased GFR (106.7±45.3 to 86.3±42.6 ml/min, p<0.05). Protein shakes had a neutral effect. There were no correlations between changes in inulin clearance and PI. At Doppler, RRI and PuI increased after meat intake (from 0.647±0.029 to 0.694±0.050, p<0.05 and from 1.130±0.087 to 1.318±0.163, p<0.05 respectively), but their changes also did not correlate with changes in inulin clearance. Results were similar in both sexes. Conclusions: CEUS is no valuable alternative for inulin clearance to measure RFR. Meat ingestion leads to modest changes in renal Doppler parameters and to glomerular hyperfiltration in both women and men, while protein shakes and L-arginine do not

Cortical perfusion as assessed with contrast-enhanced ultrasound is lower in patients with chronic kidney disease than in healthy subjects but increases under low salt conditions.

Disturbances in renal microcirculation play an important role in the pathophysiology of chronic kidney disease (CKD), but the lack of easy accessible techniques hampers our understanding of the regulation of the renal microcirculation in humans. We assessed whether contrast-enhanced ultrasonography (CEUS) can identify differences in cortical perfusion and alterations induced by different dietary salt intakes in CKD patients and controls. Participants underwent CEUS twice: once after 5 days of high salt intake (HS), and again after 5 days of low salt diet (LS). Sonovue® (0.015 ml/kg/min) was perfused as contrast agent and four consecutive destruction-reperfusion sequences were analyzed per visit. Primary outcome measure was the (change in) mean perfusion index (PI) of the renal cortex. Forty healthy volunteers (mean age±SD 50±8 years) and 18 CKD stage 2-4 patients (aged 55±11 years, eGFR 54±28 ml/min/1.73m²) were included and underwent CEUS without side effects. Under HS conditions, cortical PI was significantly lower in CKD patients (1618±1352 vs 3176 ±2278 arbitrary units in controls, p = 0.034). Under LS, renal PI increased in CKD patients (with +1098 to 2716 ±1540 a.u., p = 0.048), whereas PI remained stable in controls. In continuous analysis, PI correlated with eGFR (spearman's r = 0.54, p = 0.005) but not with age, sex, blood pressure or aldosterone levels. CEUS identified important reductions in cortical micro-perfusion in patients with moderate CKD. Lowering salt intake increased perfusion in CKD patients, but not in controls, underlining the benefits of a low salt diet in CKD patients. Whether a low perfusion index is an early sign of kidney damage and predicts renal function decline needs further study