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BACKGROUND: The primary genetic risk factor for heritable pulmonary arterial hypertension is the presence of monoallelic mutations in the BMPR2 gene. The incomplete penetrance of BMPR2 mutations implies that additional triggers are necessary for pulmonary arterial hypertension occurrence. Pulmonary artery stenosis directly raises pulmonary artery pressure, and the redirection of blood flow to unobstructed arteries leads to endothelial dysfunction and vascular remodeling. We hypothesized that right pulmonary artery occlusion (RPAO) triggers pulmonary hypertension (PH) in rats with Bmpr2 mutations. METHODS AND RESULTS: Male and female rats with a 71 bp monoallelic deletion in exon 1 of Bmpr2 and their wild-type siblings underwent acute and chronic RPAO. They were subjected to full high-fidelity hemodynamic characterization. We also examined how chronic RPAO can mimic the pulmonary gene expression pattern associated with installed PH in unobstructed territories. RPAO induced precapillary PH in male and female rats, both acutely and chronically. Bmpr2 mutant and male rats manifested more severe PH compared with their counterparts. Although wild-type rats adapted to RPAO, Bmpr2 mutant rats experienced heightened mortality. RPAO induced a decline in cardiac contractility index, particularly pronounced in male Bmpr2 rats. Chronic RPAO resulted in elevated pulmonary IL-6 (interleukin-6) expression and decreased Gdf2 expression (corrected P value<0.05 and log2 fold change>1). In this context, male rats expressed higher pulmonary levels of endothelin-1 and IL-6 than females. CONCLUSIONS: Our novel 2-hit rat model presents a promising avenue to explore the adaptation of the right ventricle and pulmonary vasculature to PH, shedding light on pertinent sex- and gene-related effects.
RESUMO
Background: The MELODY system allows for performing ultrasonography on a patient remotely and has been proposed to assess disease characteristics in the context of the coronavirus disease 2019 (COVID-19) pandemic. The aim of this interventional crossover study was to address the feasibility of the system in children aged 1 to 10 years old. Methods: Children underwent ultrasonography with a telerobotic ultrasound system followed by a second conventional examination by a different sonographer. Results: In total, 38 children were enrolled, and 76 examinations were performed, with 76 scans analyzed. The mean [standard deviation (SD)] age of participants was 5.7 (2.7) years (range, 1-10 years). We found substantial agreement between telerobotic and conventional ultrasonography [κ=0.74 (95% CI: 0.53-0.94), P<0.005]. The mean (SD) duration was longer for telerobotic than conventional examinations [26.0 (2.5) vs. 13.9 (11.2) min, P<0.0001]. Abdominal organs and abnormalities were similarly visualized on telerobotic and conventional ultrasonography. Cardiac echocardiography provided reliable diagnoses, with non-significantly different measurements with both techniques, although the visualization score was significantly higher with conventional than telerobotic ultrasonography (P<0.05). On lung analysis, both examinations identified consolidations and pleural effusion, whereas visualization and total lung score were similar with the 2 techniques. Overall, 45% of parents reported that their children felt less pressure with the telerobotic system. Conclusions: Telerobotic ultrasonography may be effective, feasible, and well-tolerated in children.
RESUMO
OBJECTIVES: A detailed preoperative evaluation of coronary anatomy is mandatory before surgical intervention for tetralogy of Fallot. In pediatric patients, the preoperative evaluation of coronary anatomy has relied classically on conventional angiographic analysis and, more recently, on echocardiographic analysis, which have well-known limitations and complications. Recent technological improvements allow the use of multislice computed tomographic analysis to evaluate coronary artery anatomy in very young children, even those with high heart rates. The purpose of this prospective study was to assess the accuracy of preoperative dual-source computed tomographic analysis in detecting coronary artery abnormalities by using surgical findings as the reference standard. METHODS: We prospectively evaluated 100 patients with tetralogy of Fallot before surgical intervention between November 2006 and September 2009 by using dual-source computed tomographic analysis with either retrospective, electrocardiographically gated, helical computed tomographic analysis or prospective, electrocardiographically triggered, sequential computed tomographic acquisition. The patients had a median age of 6.8 months (range, 1.2 months-6.8 years) and a median weight of 7.9 kg (range, 3-30 kg). RESULTS: Compared with surgical findings, dual-source computed tomographic analysis had 100% sensitivity and 100% specificity for detecting coronary artery abnormalities. Major coronary artery abnormalities were found in 7 (7%) patients. The radiation dose was low. CONCLUSIONS: Dual-source computed tomographic analysis is an accurate and noninvasive tool for delineating coronary artery anatomy before surgical intervention in children with tetralogy of Fallot. Dual-source computed tomographic analysis might deserve to be used routinely instead of angiographic analysis and in combination with echocardiographic analysis for the preoperative assessment of patients with tetralogy of Fallot.
