ABSTRACT
Impaired ventricular myocardial mechanics are observed in patients with repaired tetralogy of Fallot (rTOF). Effects of pulmonary valve replacement (PVR) on ventricular remodeling are controversial. The objective was to assess the impact of surgical PVR on ventricular mechanics in pediatric patients after rTOF. Speckle-tracking analysis was performed in 50 rTOF children, aged 12.6 ± 3.3 years, pre-operatively and 14.5 ± 2.2 months post-PVR. Early post-operative studies 2.2 ± 0.6 months post-PVR were performed in 28 patients. Cardiac magnetic resonance (CMR) pre- and post-PVR was collected. Mid-term post-PVR right ventricular (RV) longitudinal strain increased above pre-operative strain (-19.2 ± 2.7 to -22.0 ± 3.0%, p < 0.001) with increases observed in individual RV segments. Left ventricular (LV) strain did not differ at medium-term follow-up. LV and RV longitudinal strain was reduced early post-operatively, followed by recovery of biventricular systolic strain by mid-term follow-up. CMR RV end-diastolic indexed volumes correlated with RV strain pre-operatively (r = 0.432, p = 0.005) and at mid-term follow-up (r = 0.532, p = 0.001). Volume-loaded RVs had reduced early RV basal longitudinal strain compared to pressure-loading conditions. Reversed basal counterclockwise rotation was associated with lower mid-term global LV and basal RV strain compared to patients with normal rotation. An increase in mid-term global and regional RV strain beyond pre-operative values suggests positive RV remodeling and adaptation occurs in children post-PVR. Patients with larger pre-operative RV volumes had lower RV strain post-operatively. The impact of LV rotation on RV mechanics highlights the presence of ventriculo-ventricular interactions. These findings have important clinical implications in pediatric rTOF patients towards identifying pre-operative factors that predict RV post-operative remodeling.
Subject(s)
Cardiac Surgical Procedures , Heart Valve Prosthesis Implantation , Myocardial Contraction , Pulmonary Valve Insufficiency/surgery , Pulmonary Valve/surgery , Tetralogy of Fallot/surgery , Ventricular Function, Left , Ventricular Function, Right , Ventricular Remodeling , Adaptation, Physiological , Adolescent , Biomechanical Phenomena , Cardiac Surgical Procedures/adverse effects , Child , Cross-Sectional Studies , Echocardiography , Female , Heart Valve Prosthesis Implantation/adverse effects , Humans , Magnetic Resonance Imaging , Male , Observer Variation , Predictive Value of Tests , Pulmonary Valve/diagnostic imaging , Pulmonary Valve/physiopathology , Pulmonary Valve Insufficiency/diagnostic imaging , Pulmonary Valve Insufficiency/etiology , Pulmonary Valve Insufficiency/physiopathology , Reproducibility of Results , Retrospective Studies , Stress, Mechanical , Tetralogy of Fallot/physiopathology , Time Factors , Treatment OutcomeABSTRACT
This article provides expert opinion on the use of cardiovascular magnetic resonance (CMR) in young patients with congenital heart disease (CHD) and in specific clinical situations. As peculiar challenges apply to imaging children, paediatric aspects are repeatedly discussed. The first section of the paper addresses settings and techniques, including the basic sequences used in paediatric CMR, safety, and sedation. In the second section, the indication, application, and clinical relevance of CMR in the most frequent CHD are discussed in detail. In the current era of multimodality imaging, the strengths of CMR are compared with other imaging modalities. At the end of each chapter, a brief summary with expert consensus key points is provided. The recommendations provided are strongly clinically oriented. The paper addresses not only imagers performing CMR, but also clinical cardiologists who want to know which information can be obtained by CMR and how to integrate it in clinical decision-making.
Subject(s)
Cardiovascular Diseases/diagnosis , Heart Defects, Congenital/diagnosis , Imaging, Three-Dimensional/standards , Magnetic Resonance Imaging, Cine/standards , Practice Guidelines as Topic/standards , Child , Child, Preschool , Consensus , Europe , Female , Humans , Image Interpretation, Computer-Assisted , Imaging, Three-Dimensional/methods , Infant , Infant, Newborn , Magnetic Resonance Imaging, Cine/methods , Male , Societies, Medical/standardsABSTRACT
This article provides expert opinion on the use of cardiovascular magnetic resonance (CMR) in young patients with congenital heart disease (CHD) and in specific clinical situations. As peculiar challenges apply to imaging children, paediatric aspects are repeatedly discussed. The first section of the paper addresses settings and techniques, including the basic sequences used in paediatric CMR, safety, and sedation. In the second section, the indication, application, and clinical relevance of CMR in the most frequent CHD are discussed in detail. In the current era of multimodality imaging, the strengths of CMR are compared with other imaging modalities. At the end of each chapter, a brief summary with expert consensus key points is provided. The recommendations provided are strongly clinically oriented. The paper addresses not only imagers performing CMR, but also clinical cardiologists who want to know which information can be obtained by CMR and how to integrate it in clinical decision-making.
Subject(s)
Cardiovascular Diseases/diagnosis , Heart Defects, Congenital/diagnosis , Image Interpretation, Computer-Assisted , Imaging, Three-Dimensional/standards , Magnetic Resonance Imaging, Cine/standards , Practice Guidelines as Topic/standards , Child , Child, Preschool , Consensus , Europe , Female , Humans , Imaging, Three-Dimensional/methods , Infant , Infant, Newborn , Magnetic Resonance Imaging, Cine/methods , Male , Societies, Medical/standardsABSTRACT
PURPOSE: We report a case with initial misinterpretation of the radionuclide angiocardiographic study that was obtained in a child with persistent tachypnea and concern for residual left to right shunt after prior repair of total anomalous pulmonary veins and an atrial septal defect. MATERIALS AND METHODS: Ultrasound, radionuclide angiocardiogram, and magnetic resonance imaging studies were obtained. RESULTS: The radionuclide study was ordered after an unremarkable ultrasound. Unsuspected severely reduced left pulmonary arterial flow associated with high-grade ipsilateral pulmonary venous obstruction led to misinterpretation of the radionuclide study as a large residual shunt. Later replotting of the graphic data using each lung separately corrected the error. Magnetic resonance played a key role in making the correct diagnosis. CONCLUSIONS: Significant asymmetric pulmonary flow due to vascular obstruction is an important additional potential pitfall to recognize in interpreting radionuclide angiocardiographic studies.
Subject(s)
Artifacts , Image Enhancement/methods , Lung/diagnostic imaging , Postoperative Complications/diagnostic imaging , Pulmonary Artery/diagnostic imaging , Pulmonary Veno-Occlusive Disease/diagnostic imaging , Pulmonary Veno-Occlusive Disease/etiology , Blood Flow Velocity , Humans , Image Interpretation, Computer-Assisted/methods , Infant , Lung/blood supply , Postoperative Care/methods , Pulmonary Circulation , Radionuclide ImagingABSTRACT
Arrhythmias occur as a life-threatening complication in adults with severe head injuries. A wide spectrum of brady- and tachyarrhythmias and different pathogenetic mechanisms have been described. We report an 8-year-old boy with traumatic brain injury who developed a variety of independent types of arrhythmias during the course of his illness, including supraventricular and ventricular extrasystoles, prolonged QT duration and ventricular fibrillation, accelerated junctional rhythm, and reentry tachycardia. Each arrhythmia may have had a distinct pathogenic pathway, and not all were associated with raised intracranial pressure.
Subject(s)
Arrhythmias, Cardiac/etiology , Brain Injuries/complications , Intracranial Hypertension/etiology , Bradycardia/etiology , Brain Injuries/physiopathology , Child , Electrocardiography , Humans , Intracranial Hypertension/physiopathology , Long QT Syndrome/etiology , Male , Tachycardia/etiologyABSTRACT
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare condition. The majority of cases present with impaired left ventricular function. We report on a premature infant who was diagnosed at a gestational age near term with ALCAPA during routine cardiac examination. The patient showed no signs of myocardial ischemia and is doing well after corrective surgery. This is the youngest patient reported with ALCAPA and preserved myocardial function.
Subject(s)
Coronary Vessel Anomalies , Infant, Premature , Pulmonary Artery/abnormalities , Ventricular Function, Left , Coronary Vessel Anomalies/diagnostic imaging , Coronary Vessel Anomalies/surgery , Echocardiography, Doppler, Color , Female , Humans , Infant, NewbornABSTRACT
Here we describe the identification and characterization of a physiological marker that is associated with the chloroquine-resistant (CQR) phenotype in the human malarial parasite Plasmodium falciparum. Single cell in vivo pH measurements revealed that CQR parasites consistently have an elevated cytoplasmic pH compared to that of chloroquine-sensitive (CQS) parasites because of a constitutively activated Na+/H+ exchanger (NHE). Together, biochemical and physiological data suggest that chloroquine activates the plasmodial NHE of CQS parasites, resulting in a transitory phase of rapid sodium/hydrogen ion exchange during which chloroquine is taken up by this protein. The constitutively stimulated NHE of CQR parasites are capable of little or no further activation by chloroquine. We propose that the inability of chloroquine to stimulate its own uptake through the constitutively activated NHE of resistant parasites constitutes a minimal and necessary event in the generation of the chloroquine-resistant phenotype.
