Cardiac complications are the leading cause of death in patients with Duchenne muscular dystrophy (DMD). Two-dimensional echocardiography is the current standard for monitoring of LV systolic function in these patients, but it might not detect early systolic dysfunction. The current study examined the use of speckle tracking echocardiography (STE) to detect early signs of cardiac dysfunction in DMD patients. A retrospective review of charts and offline strain analysis of transthoracic echocardiographic studies of DMD patients at our institution from April 2014 to January 2015 were performed and compared to age-matched healthy male subjects. Nineteen DMD patients (age range 12.6 ± 3.1 years) with normal ejection fraction and shortening fraction were compared with sixteen controls. The global circumferential strain was lower in DMD patients compared with controls (-14.7 ± 4.7 vs. -23.1 ± 2.9 %, respectively, p value: 0.001). Circumferential strain measured at basal, mid-ventricular and apical parasternal short-axis views was lower in DMD patients compared with controls. Segmental circumferential strain was lower in DMD patients in most segments compared with controls. The global longitudinal strain was lower in DMD patients compared with controls (-13.6 ± 5 vs. -18.8 ± 3 %, respectively, p value: 0.001). Segmental longitudinal strain measured in various segments was lower in DMD patients compared with controls. DMD patients can have occult cardiovascular dysfunction as shown by reduction in circumferential and longitudinal strain measurements with STE despite normal standard echocardiographic parameters. The clinical significance of early detection of cardiac dysfunction in these patients warrants further studies.
In isolated unilateral ductal origin of a pulmonary artery (DOPA), intervention to establish reperfusion of the affected lung without direct re-anastomosis may lead to pulmonary hypertension (PH) in the contralateral lung. Multicenter retrospective review of patients with unilateral DOPA, who underwent palliation with a ductal stent (DS) or Blalock-Taussig (BT) shunt with subsequent development of PH in the contralateral lung, was conducted. Ten patients (4 females; median weight 3.2 kg, range 2.1-5.2) who underwent DS or BT shunt and developed contralateral PH were identified. Eight infants had right-sided DOPA. Stents/shunt used had a median diameter of 3.5 mm (range 2.5-5.2). After DS in 9 patients, 7 patients were exclusively treated with medical therapies, whereas 2 patients received intermediate procedures: one received an additional contralateral DS and other underwent surgical banding of the DS prior to PA reimplantation. Seven patients who underwent DS and one patient with BT shunt underwent PA reimplantation at median of 3.3 (0.6-18) months. PA pressure was documented to be normal in 5 patients immediately following PA reimplantation, 1 year later in 2 patients, and 1 patient is on Tadalafil with elevated PVR of 5.5 indexed Wood units. One patient died and one patient is awaiting surgery with normal PA pressure. We describe the development of severe contralateral PH following DS or BT shunt as the initial intervention for unilateral DOPA. Pulmonary hypertension resolved in 7/8 patients who underwent surgical PA reimplantation. The cause of PH in the normally connected lung in these cases remains unclear.
The Fontan procedure was first performed in the seventies as a palliation for patients with single ventricle physiology. A feared complication after a Fontan procedure is the development of protein losing enteropathy (PLE). Systemic inflammation has a negative effect on the intestinal barrier integrity, which has supported the use of steroids in this setting. To the best of our knowledge there are no studies linking intestinal inflammation in patients with PLE after Fontan. The objective of this study was to identify the presence of intestinal inflammation measured by FC in patients with PLE after a Fontan procedure. A cross-sectional analysis was performed examining 23 stool samples from 23 Fontan patients for both Fecal alpha-1-antitrypsin (FA1AT) and FC with and without PLE. The median FC was 21 mcg/gm of stool (IQR: 15.7-241 mcg/gm of stool), and the median FA1AT was 40 mg/dL (IQR: 30-220 mg/dL). The median FC and FA1AT were significantly higher in the PLE group than in the Non-PLE group (p = 0.002 and p < 0.0001, respectively). Significantly elevated levels of FC were demonstrated in Fontan patients with PLE, which correlated with the elevated levels of FA1AT. Inversely, levels of FC in Fontan patients without suspected PLE were within the normal range. To our knowledge, this is the first study to demonstrate intestinal inflammation using FC in the setting of PLE within this cohort, and may prove to be useful as a diagnostic tool in its treatment.
We report a substantial enhancement of the oxide-ion conductivity in SrMoO achieved by Nb doping the Mo sites. This series responds to the formula: SrMoNbO (with x = 0.0, 0.5 and 1.0). The original structure can be related to the conventional double perovskite; however, it presents a broken corner sharing connectivity of the octahedral framework, hence leading to a complex and highly defective network. The samples were prepared via citrate precursor method, followed by thermal treatments at 1300 °C for 12 hours in air. The crystal structures were refined from X-ray and neutron powder diffraction (NPD) data. A phase transition from tetragonal to cubic symmetry is identified in a temperature-dependent NPD study, driven by an oxygen delocalization effect. The ionic conductivity measured by impedance spectroscopy is enhanced upon Nb-doping; the x = 1 doped phase exhibits a threefold increase compared to the pristine SrMoO oxide, with conductivity values of 7.6 × 10 and 2.7 × 10 S·cm at 650 and 800 °C, which are even greater than for YSZ in the 650-800 °C temperature range, and close to those reported for other state-of-the art solid-oxide electrolytes.
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