Quality check of cardiac MRI exams for Fallot patients: Interest of a simple formula to detect invalid exams

PurposeCardiac MRI (CMR) is the key exam for Fallot patients but remains tricky. The CMR report should at least mention left and right ventricle end-diastole volumes (Vl and Vr), ejection fraction (EFl and EFr) and pulmonary regurgitation (PR). Obviously, these variables are linked together by basic physiology rules and indeed Vl×EFl=Vr×EFr×(1-PR). We investigated the interest of using such formula as quality check during Fallot CMR exams in our center.Methods98 consecutive CMR examinations for Fallot (or Fallot-like) cardiopathy between 2010 and 2014 were retrospectively included. The exams failing to pass the formula (with a 10% tolerance) constituted the Invalid-group and a control group of the same size was also constituted. CMR of both groups were randomly submitted to a blinded senior observer. The inter-observer limits of agreements were compared for the different variables within both groups.Results(Fig. 1) 12 CMR (12%) failed to pass the validation formula. From the 24 reanalyzed CMR, only 4 failed to pass the formula (all from the Invalid-group). Two had persistent defect (VSD or ASD) which were not mentioned to the radiologist and not detected during the CMR. Two had significant artefacts in the aorta or pulmonary trunk due to sterna wires. The inter-observer disagreements for the 8 other CMR of the Invalid-group concerned the Right ventricle end-diastole volume (P<0.05).ConclusionThe use of a simple formula as quality check of CMR examinations for Fallot patients was useful to detect a total of 12% of CMR with issues. 8% of the CMR corresponded to uncertain right ventricle contours, 2% to persistent septal defects that should have been noticed during the examination and 2% to unreliable aortic or pulmonary flow due to artifacts. The formula could have permitted either to detect the anomalies or at least to conclude that the quality of the exams was impaired

A constant and similar assembly defect of mitochondrial respiratory chain complex I allows rapid identification of NDUFS4 mutations in patients with Leigh syndrome

AbstractIsolated complex I deficiency is a frequent cause of respiratory chain defects in childhood. In this study, we report our systematic approach with blue native PAGE (BN-PAGE) to study mitochondrial respiratory chain assembly in skin fibroblasts from patients with Leigh syndrome and CI deficiency. We describe five new NDUFS4 patients with a similar and constant abnormal BN-PAGE profile and present a meta-analysis of the literature. All NDUFS4 mutations that have been tested with BN-PAGE result in a constant and similar abnormal assembly profile with a complete loss of the fully assembled complex I usually due to a truncated protein and the loss of its canonical cAMP dependent protein kinase phosphorylation consensus site. We also report the association of abnormal brain MRI images with this characteristic BN-PAGE profile as the hallmarks of NDUFS4 mutations and the first founder NDUFS4 mutations in the North-African population

Fast assessment of long axis strain with standard cardiovascular magnetic resonance: a validation study of a novel parameter with reference values

Background: Assessment of longitudinal function with cardiovascular magnetic resonance (CMR) is limited to measurement of systolic excursion of the mitral annulus (MAPSE) or elaborate strain imaging modalities. The aim of this study was to develop a fast assessable parameter for the measurement of long axis strain (LAS) with CMR. Methods: 40 healthy volunteers and 125 patients with different forms of cardiomyopathy were retrospectively analyzed. Four different approaches for the assessment of LAS with CMR measuring the distance between the LV apex and a line connecting the origins of the mitral valve leaflets in enddiastole and endsystole were evaluated. Values for LAS were calculated according to the strain formula. Results: LAS derived from the distance of the epicardial apical border to the midpoint of the line connecting the mitral valve insertion points (LAS-epi/mid) proved to be the most reliable parameter for the assessment of LAS among the different approaches. LAS-epi/mid displayed the highest sensitivity (81.6 %) and specificity (97.5 %), furthermore showing the best correlation with feature tracking (FTI) derived transmural longitudinal strain (r = 0.85). Moreover, LAS-epi/mid was non-inferior to FTI in discriminating controls from patients (Area under the curve (AUC) = 0.95 vs. 0.94, p = NS). The time required for analysis of LAS-epi/mid was significantly shorter than for FTI (67 ± 8 s vs. 180 ± 14 s, p &lt; 0.0001). Additionally, LAS-epi/mid performed significantly better than MAPSE (Delta AUC = 0.09; p &lt; 0.005) and the ejection fraction (Delta AUC = 0.11; p = 0.0002). Reference values were derived from 234 selected healthy volunteers. Mean value for LAS-epi/mid was −17.1 ± 2.3 %. Mean values for men were significantly lower compared to women (−16.5 ± 2.2 vs. -17.9 ± 2.1 %; p &lt; 0.0001), while LAS decreased with age. Conclusions: LAS-epi/mid is a novel and fast assessable parameter for the analysis of global longitudinal function with non-inferiority compared to transmural longitudinal strain

Tectonic structure, evolution, and the nature of oceanic core complexes and their detachment fault zones (13°20′N and 13°30′N, Mid Atlantic Ridge)

Microbathymetry data, in situ observations, and sampling along the 138200N and 138200N oceanic core complexes (OCCs) reveal mechanisms of detachment fault denudation at the seafloor, links between tectonic extension and mass wasting, and expose the nature of corrugations, ubiquitous at OCCs. In the initial stages of detachment faulting and high-angle fault, scarps show extensive mass wasting that reduces their slope. Flexural rotation further lowers scarp slope, hinders mass wasting, resulting in morphologically complex chaotic terrain between the breakaway and the denuded corrugated surface. Extension and drag along the fault plane uplifts a wedge of hangingwall material (apron). The detachment surface emerges along a continuous moat that sheds rocks and covers it with unconsolidated rubble, while local slumping emplaces rubble ridges overlying corrugations. The detachment fault zone is a set of anostomosed slip planes, elongated in the alongextension direction. Slip planes bind fault rock bodies defining the corrugations observed in microbathymetry and sonar. Fault planes with extension-parallel stria are exposed along corrugation flanks, where the rubble cover is shed. Detachment fault rocks are primarily basalt fault breccia at 138200N OCC, and gabbro and peridotite at 138300N, demonstrating that brittle strain localization in shallow lithosphere form corrugations, regardless of lithologies in the detachment zone. Finally, faulting and volcanism dismember the 138300N OCC, with widespread present and past hydrothermal activity (Semenov fields), while the Irinovskoe hydrothermal field at the 138200N core complex suggests a magmatic source within the footwall. These results confirm the ubiquitous relationship between hydrothermal activity and oceanic detachment formation and evolution

Depth-varying seismogenesis on an oceanic detachment fault at 13°20'N on the Mid-Atlantic Ridge

Extension at slow- and intermediate-spreading mid-ocean ridges is commonly accommodated through slip on long-lived faults called oceanic detachments. These curved, convex-upward faults consist of a steeply-dipping section thought to be rooted in the lower crust or upper mantle which rotates to progressively shallower dip-angles at shallower depths. The commonly-observed result is a domed, sub-horizontal oceanic core complex at the seabed. Although it is accepted that detachment faults can accumulate kilometre-scale offsets over millions of years, the mechanism of slip, and their capacity to sustain the shear stresses necessary to produce large earthquakes, remains subject to debate. Here we present a comprehensive seismological study of an active oceanic detachment fault system on the Mid-Atlantic Ridge near 13°20′N, combining the results from a local ocean-bottom seismograph deployment with waveform inversion of a series of larger teleseismically-observed earthquakes. The unique coincidence of these two datasets provides a comprehensive definition of rupture on the fault, from the uppermost mantle to the seabed. Our results demonstrate that although slip on the deep, steeply-dipping portion of detachment faults is accommodated by failure in numerous microearthquakes, the shallow, gently-dipping section of the fault within the upper few kilometres is relatively strong, and is capable of producing large-magnitude earthquakes. This result brings into question the current paradigm that the shallow sections of oceanic detachment faults are dominated by low-friction mineralogies and therefore slip aseismically, but is consistent with observations from continental detachment faults. Slip on the shallow portion of active detachment faults at relatively low angles may therefore account for many more large-magnitude earthquakes at mid-ocean ridges than previously thought, and suggests that the lithospheric strength at slow-spreading mid-ocean ridges may be concentrated at shallow depths

Syndrome de Sandifer chez une enfant de 5 mois admise pour des spasmes épileptiques

International audienceSandifer's syndrome is a dystonic movement disorder in infants with gastroesophageal reflux (GER). It is probably misdiagnosed as epileptic seizures. We report the case of a 5-month-old infant with no past medical history admitted to a pediatric unit for suspicion of infantile spasms. She presented with dystonic movements of the upper left limb with left blepharospasm and an occasional dystonic head posture. Physical examination, EEG, brain MRI, and blood analysis were normal. Since the baby experienced regurgitations, Sandifer's syndrome was suspected and confirmed by 24-h esophageal pH monitoring that documented pathological GER. The dystonic symptoms quickly disappeared under treatment with thickened infant formula and sodium alginate. Infantile spasms remain the first diagnosis to explore with axial or para-axial dystonic postural events. Sandifer's syndrome should be retained when neurological investigations are normal and abnormal movements disappear under treatment of proven GER. Prognosis is excellent

Auto-assemblages pseudopeptidiques à activité antimicrobienne.

Communication oral