Cardiology in the young
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Cardiology in the young · Jun 2016
Comparative StudyComparison of cryoablation with 3D mapping versus conventional mapping for the treatment of atrioventricular re-entrant tachycardia and right-sided paraseptal accessory pathways.
Aim Transcatheter cryoablation is a well-established technique for the treatment of atrioventricular nodal re-entry tachycardia and atrioventricular re-entry tachycardia in children. Fluoroscopy or three-dimensional mapping systems can be used to perform the ablation procedure. The aim of this study was to compare the success rate of cryoablation procedures for the treatment of right septal accessory pathways and atrioventricular nodal re-entry circuits in children using conventional or three-dimensional mapping and to evaluate whether three-dimensional mapping was associated with reduced patient radiation dose compared with traditional mapping. ⋯ The use of three-dimensional mapping compared with the conventional fluoroscopy-guided method for cryoablation of right septal accessory pathways and atrioventricular nodal re-entry circuits in children was associated with a significant reduction in patient radiation dose without an increase in success rate.
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Cardiology in the young · Jun 2016
Effect of Hybrid stage 1 procedure on ventricular function in infants with hypoplastic left heart syndrome.
The effect of Hybrid stage 1 palliation for hypoplastic left heart syndrome on right ventricular function is unknown. We sought to compare right ventricular function in normal neonates and those with hypoplastic left heart syndrome before Hybrid palliation and to assess the effect of Hybrid palliation on right ventricular function, using the right ventricular myocardial performance index and the ratio of systolic and diastolic durations. ⋯ Right ventricular myocardial performance index and ratio of systolic and diastolic durations were significantly higher in infants with hypoplastic left heart syndrome before intervention compared with controls. The ratio of systolic and diastolic durations increased significantly 2 weeks after Hybrid palliation. Our data suggest that infants with hypoplastic left heart syndrome have right ventricular dysfunction before intervention, which worsens over 2 weeks after Hybrid palliation.
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Cardiology in the young · Apr 2016
Determining bronchial morphology for the purposes of segregating so-called heterotaxy.
Introduction Heterotaxy is a unique clinical entity in which lateralisation of the thoraco-abdominal organs is abnormal, typically with isomerism of the bronchial tree and atrial appendages. This study was carried out to determine whether routine clinical imaging such as chest radiographs, angiographic images, and CT/MRI can determine bronchial isomerism, and how sidedness of bronchial isomerism correlates with overall features anticipated in hearts with isomeric atrial appendages. Methods and results We identified 73 patients with heterotaxy, in whom imaging clearly demonstrated the bronchial tree, seen at our institution since 1998. We calculated bronchial angles and lengths using all the available imaging modalities to determine the presence and sidedness of bronchial isomerism. This was then compared with the anticipated presence of isomeric atrial appendages based on the overall clinical findings, as the appendages themselves had not specifically been imaged. The ratio of bronchial lengths revealed bronchial isomerism in all patients, with bronchial angles permitting distinction of right as opposed to left isomerism. We noted discordances between the identified bronchial isomerism and the presumed arrangement of the atrial appendages in nearly 20% of the patients in our cohort. ⋯ Routine clinical imaging with chest radiographs, angiographic imaging, and CT/MRI can determine the presence of bronchial isomerism in patients with so-called heterotaxy. Right as opposed to left isomerism can be distinguished based on bronchial angles. The finding of bronchial isomerism correlates well, but not totally, with the presumed isomerism of the atrial appendages as predicted from the identified intra-cardiac morphology.
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Cardiology in the young · Mar 2016
Effects of surgical en bloc rotation of the arterial trunk on the conduction system in children with transposition of the great arteries, ventricular septal defect and pulmonary stenosis.
The standard surgical management of patients with transposition of the great arteries, ventricular septal defect, and pulmonary stenosis is the Rastelli operation. Recently, en bloc rotation of the arterial trunk, by cutting out the aortic and the pulmonary root in one block and by rotating it 180°, has been introduced as a new option for anatomical repair. ⋯ Our data suggest that en bloc rotation of the arterial trunk seems not to have more negative effects on the conduction system than the Rastelli operation.
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Cardiology in the young · Feb 2016
Randomized Controlled TrialPharmacokinetics of intravenous sildenafil in children with palliated single ventricle heart defects: effect of elevated hepatic pressures.
Aims Sildenafil is frequently prescribed to children with single ventricle heart defects. These children have unique hepatic physiology with elevated hepatic pressures, which may alter drug pharmacokinetics. We sought to determine the impact of hepatic pressure on sildenafil pharmacokinetics in children with single ventricle heart defects. ⋯ The analysis included a median (range) of 4 (2-5) pharmacokinetic samples per child. The final structural model was a two-compartment model for sildenafil with a one-compartment model for des-methyl-sildenafil (active metabolite), with assumed 100% sildenafil to des-methyl-sildenafil conversion. Sildenafil clearance was unaffected by hepatic pressure (clearance=0.62 L/hour/kg); however, clearance of des-methyl-sildenafil (1.94×(hepatic pressure/9)(-1.33) L/hour/kg) was predicted to decrease ~7-fold as hepatic pressure increased from 4 to 18 mmHg. Predicted drug exposure was increased by ~1.5-fold in subjects with hepatic pressures ⩾10 versus <10 mmHg (median area under the curve=533 versus 792 µg*h/L). Discussion Elevated hepatic pressure delays clearance of the sildenafil metabolite - des-methyl-sildenafil - and increases drug exposure. We speculate that this results from impaired biliary clearance. Hepatic pressure should be considered when prescribing sildenafil to children. These data demonstrate the importance of pharmacokinetic assessments in patients with unique cardiovascular physiology that may affect drug metabolism.