Au, Chun Ting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves xxvii-lv). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / ABSTRACT / In English --- p.ii / In Chinese --- p.v / LIST OF TABLES --- p.vii / ABBREVIATIONS / For Units --- p.ix / For Prefixes of the international system of units --- p.ix / For Terms commonly used in the report --- p.x / STATEMENT OF WORK DONE --- p.xvi / Chapter CHAPTER 1 --- Overview of Childhood Obstructive Sleep Apnea Syndrome (OSAS) / Chapter 1.1. --- Clinical Features of Childhood OSAS --- p.1 / Chapter 1.2. --- Definition of Childhood OSAS --- p.2 / Chapter 1.3. --- Prevalence of Childhood OSAS --- p.3 / Chapter 1.4. --- Pathophysiology --- p.4 / Chapter 1.5. --- Risk Factors --- p.6 / Chapter 1.6. --- Diagnosis --- p.10 / Chapter 1.7. --- Treatment / Chapter 1.7.1. --- Tonsillectomy and Adenoidectomy (T&A) --- p.12 / Chapter 1.7.2. --- Continuous Positive Airway Pressure (CPAP) --- p.14 / Chapter 1.7.3. --- Corticosteroids --- p.15 / Chapter 1.7.4. --- Leukotriene Receptor Antagonist --- p.16 / Chapter 1.8. --- Complications of Childhood OSAS / Chapter 1.8.1. --- Growth Failure --- p.17 / Chapter 1.8.2. --- Neurocognitive Abnormalities --- p.19 / Chapter 1.8.3. --- Cardiovascular Abnormalities --- p.20 / Chapter CHAPTER 2 --- Cardiovascular Complications of OSAS in Adults (Literature Review) / Chapter 2.1. --- Acute Effects of OSAS on Cardiovascular System --- p.21 / Chapter 2.2. --- Chronic Effects of OSAS on Cardiovascular System --- p.23 / Chapter 2.3. --- Hypertension --- p.24 / Chapter 2.4. --- Heart Failure --- p.28 / Chapter 2.5. --- Pulmonary Hypertension --- p.30 / Chapter 2.6. --- Arrhythmias --- p.31 / Chapter 2.7. --- Cardiac Ischemia and Vascular Disease --- p.33 / Chapter 2.8. --- Stroke --- p.34 / Chapter CHAPTER 3 --- Cardiovascular Complications of Childhood OSAS (Literature Review) / Chapter 3.1. --- Blood Pressure --- p.37 / Chapter 3.2. --- Ventricular Structure and Function --- p.40 / Chapter 3.3. --- Arterial Distensibility --- p.42 / Chapter 3.4. --- Heart Rate Variability --- p.42 / Chapter CHAPTER 4 --- Ambulatory Blood Pressure in Children with OSAS / Chapter 4.1. --- Introduction --- p.44 / Chapter 4.2. --- Methods / Chapter 4.2.1. --- Subjects and Study Design --- p.46 / Chapter 4.2.2. --- Polysomnography (PSG) --- p.47 / Chapter 4.2.3. --- Ambulatory Blood Pressure Measurement (ABPM) --- p.49 / Chapter 4.2.4. --- Statistical Analysis --- p.50 / Chapter 4.3. --- Results / Chapter 4.3.1. --- Subject Characteristics --- p.52 / Chapter 4.3.2. --- Blood Pressure during Wakefulness --- p.55 / Chapter 4.3.3. --- Blood Pressure during Sleep --- p.57 / Chapter 4.4. --- Discussion --- p.62 / Chapter 4.5. --- Conclusion --- p.70 / Chapter CHAPTER 5 --- Cardiac Remodeling and Dysfunction in Children with OSAS / Chapter 5.1. --- Introduction --- p.71 / Chapter 5.2. --- Methods / Chapter 5.2.1. --- Subjects and Study Design --- p.72 / Chapter 5.2.2. --- Polysomnography (PSG) --- p.74 / Chapter 5.2.3. --- Conventional Echocardiography --- p.75 / Chapter 5.2.4. --- Tissue Doppler Imaging --- p.76 / Chapter 5.2.5. --- Statistical Analysis --- p.77 / Chapter 5.3. --- Results / Chapter 5.3.1. --- Study Population --- p.79 / Chapter 5.3.2. --- Polysomnographic Findings --- p.79 / Chapter 5.3.3. --- Echocardiographic Findings / Chapter 5.3.3.1. --- Right Ventricle --- p.81 / Chapter 5.3.3.2. --- Left Ventricle --- p.83 / Chapter 5.3.4. --- Treatment Effect --- p.86 / Chapter 5.4. --- Discussion --- p.90 / Chapter 5.5. --- Conclusion --- p.95 / Chapter CHAPTER 6 --- Conclusion --- p.96 / APPENDIX I Hong Kong Children Sleep Questionnaire (Chinese) --- p.xvii / APPENDIX II Hong Kong Children Sleep Questionnaire (English) --- p.xxii / REFERENCES --- p.xxvii

Single ventricle heart defects are a rare but serious form of congenital heart disease, which affect approximately 2000 children born in the United States each year. Staged surgical palliation, culminating with the “Fontan Procedure,” is typically required to achieve adequate supply of blood to both the pulmonary and systemic circulations while avoiding chronic ventricular volume overload. This surgery reroutes the systemic veins to the pulmonary arteries, forming a total cavopulmonary connection (TCPC), to completely bypass the right side of the heart and restore a series configuration to the cardiovascular circuits. Despite improved survival through this operative course in first weeks and years of life, Fontan patients are subjected gradual attrition and decreased life expectancy through a multitude of chronic complications. It is suspected that the adverse hemodynamics of this surgically altered physiology, including those specific to the surgical TCPC, play a role in determining patient outcome. However, the small and heterogeneous patient population has hindered decisive progress and there is still not a good understanding of the optimal care strategies on a patient-by-patient basis. In recent decades, advances in medical imaging and image-based computational fluid dynamics (CFD) have redefined the realm of possibility for studying complex biomedical phenomena. Combined, these methods provide the means to create and evaluate patient-specific models of a wide range of cardiovascular structures, including the TCPC, with high fidelity. Results from these models can then be used for a wide array of different analyses, such as identifying regions of flow separation or stagnation, calculating hemodynamic power loss, or quantifying local flow distribution patterns. Through significant effort from numerous past investigators, a robust set of validated computational and image processing tools has been assembled, along with the largest library of cardiac magnetic resonance (CMR) data of TCPC anatomy and flow. These tools are leveraged in this thesis to characterize the functional implications of TCPC power loss at an unprecedented scale: we report the largest CFD analysis of patient-specific TCPC hemodynamics to date with particular focus on identifying functional correlates. Combining these data with imaging-based analysis of ventricle function, we directly compare the CFD-derived hemodynamics to the performance of the single ventricle for the first time. Motivated by the physiologic significance of these findings, the same patient-specific CFD framework is used for the translational application of prospective surgery planning for hemodynamic optimization, including the first implementation of a novel TCPC connection design hypothesized to uniquely streamline the energetic performance. We conclude with a first look at the longitudinal evolution of patient functional status to begin understanding how factors such as TCPC hemodynamics contribute to poor long-term performance in these patients.

The purpose of this phenomenological study was to determine the meaning parents give to their family's experience when they have a child awaiting corrective heart surgery. A secondary purpose was to identify appropriate interventions for nurses who deal with families during the transition period, from initial diagnosis of congenital heart disease until admission to hospital for corrective heart surgery. A convenience sample of six couples were interviewed at various times during the identified transition period, for a total of 11 interviews. An interview guide of open-ended questions provided some loose structure for the initial interviews. Analysis of the verbatim transcriptions began concurrently with data collection and continued during the formal analytic phase with meaning units emerging from the data. The parents described four facets of the experience: diagnosis of congenital heart disease, adjusting to caring for child once home, living with a child with a chronic condition, and waiting for corrective heart surgery. Not only did parents talk about how they felt during the four facets but they also described the range of coping strategies they employed through their experience. In discussing these findings within the context of other chronic illness experiences it became evident that parents draw from a common pool of coping strategies whether the child is in a chronic or more acute phase of an illness. Most of the parents in discussing their overall impressions of the experience had not found their child's illness to be as disruptive to family life as they had first anticipated. Those families with the most symptomatic infants seemed to have a particular need for an alliance with one health care professional to support them through the transition period. Generally, parents did not spend a lot of time dwelling on the corrective surgery until close to the anticipated date for that event; instead they employed various coping strategies which allowed them to normalize their lives. Implications for nursing practice which arise from these conclusions are multiple. Overall, nurses must assess the meaning that individual families give to their experience, assist families to employ suitable coping strategies, and offer support as necessary. General implications for nursing research are in the realm of studies which will further nurses' understanding of the waiting period for corrective heart surgery both from the parents' and the siblings' perspective. / Applied Science, Faculty of / Nursing, School of / Graduate

<p>  </p> <p>Heart disease is the leading cause of death for individuals with Duchenne muscular dystrophy (DMD). DMD is a devastating and progressive neuromuscular disease with no known cure. This X-linked genetic disorder affects nearly 1 in 5000 boys and manifests as debilitating muscle weakness and progressive cardiomyopathy (CM). While CM in some individuals with DMD progresses rapidly and fatally in their teenage years, others can live relatively symptom-free into their thirties or forties. Early identification and treatment can improve quality and length of life, but currently, there are no standard imaging biomarkers that can detect early onset or rapidly progressing DMD CM. Addressing this gap, we describe here a novel cardiac image analysis paradigm using 4D cardiac magnetic resonance imaging (CMR) to map left-ventricular kinematics comprehensively in DMD CM. The primary goal of this dissertation work is to introduce novel imaging biomarkers and computational methods to enable earlier diagnosis and precise prognosis for cardiac function in DMD. Central to this goal, we identified myocardial strain biomarkers that predict the early onset and rapid progression of cardiac disease in vulnerable patients. These findings bridge clinical gaps and pave the way for multi-center studies to characterize DMD CM progression and assessment of individual patient risk profiles for improved treatment and outcomes in DMD.</p>

No description available.

Les cardiopathies congénitales (CC) représentent la première cause d’anomalie malformative à la naissance. Les progrès considérables des années 80 (CEC néonatale, diagnostic prénatal) en ont modifié l’épidémiologie, avec un transfert de la mortalité de la pédiatrie à l’âge adulte. Dans ce contexte, l’évaluation de la qualité de vie liée à la santé (QdV) des enfants et adultes porteurs de CC devient un critère de jugement important, en recherche clinique comme dans les soins. Nous avons mené 4 études prospectives de QdV chez des patients avec CC: une étude chez 282 enfants de 8 à 18 ans avec CC comparés à 180 enfants contrôles; une étude sur 202 enfants avec CC corrélant QdV et VO2; une étude de QdV sur 208 adolescents et adultes porteurs d'HTAP sur CC; et une étude sur l’évolution de la QdV de 111 enfants sous AVK participant à un programme d’éducation thérapeutique. Les patients avec CC simple ont manifesté une QdV similaire à celle de la population générale. Ceux avec une cardiopathie complexe ont été préférentiellement impactés sur leur bien-être physique mais ont développé aussi des mécanismes de coping. En pédiatrie, l’évaluation de la QdV par les parents était plus péjorative mais parfois plus pertinente que celle des enfants. Nous avons mis en évidence le lien entre QdV et VO2 chez l’enfant cardiaque. Les résultats de nos travaux devraient permettre d’aider les cardiologues, cardiopédiatres et chirurgiens cardiaques dans leurs annonces diagnostiques, en particulier lors des moments cruciaux de notre sur-spécialité médico-chirurgicale: diagnostic prénatal, réanimation, transition vers l’âge adulte, prise en charge palliative d’une cardiopathie sévère. / Congenital heart diseases (CHD) are the leading cause of birth malformations. The tremendous progress since the 80’s (neonatal bypass, prenatal diagnosis) have changed the epidemiology, transferring mortality from pediatrics to adulthood. Therefore assessing the health-related quality of life (QoL) of children and adults suffering from CHD has become an important issue, in both clinical research and patients’ follow-up. We carried out 4 prospective QoL studies in patients with CHD: a study in 282 CHD children aged 8 to 18 compared with 180 controls; a study among 202 CHD children correlating their QoL scores to VO2; a QoL study among 208 adolescents and adults with PAH-CHD; and a study among 111 children in a therapeutic anticoagulation education program aiming to measure the evolution of their QoL. Patients with simple CHD showed a similar QoL to that of the control population. Those with complex heart diseases were preferentially affected in their physical well-being but also developed mechanisms of coping in other dimensions. In pediatrics, the evaluation of the QoL by parents is essential, sometimes more accurate than that of children themselves. As in previous studies in adults with heart failure, we found a significant relationship between QoL and physical performance during exercise in CHD children. The results of our work should help cardiologists, cardiac surgeons and pediatric cardiologists in their diagnostic announcement, especially during crucial moments of this medical and surgical subspecialty: prenatal diagnosis, intensive care, transition of care from adolescence to adulthood, palliative treatment of a complex CHD.

No description available.

La coagulopathie induite par la circulation extracorporelle (CEC) chez les enfants porteurs d’une cardiopathie congénitale et bénéficiant d’une chirurgie cardiaque est complexe et multifactorielle. La prise en charge de ces enfants est délicate et doit être spécifique aux caractéristiques de cette population. De plus, cette prise en charge doit être multimodale, basée sur la prévention et le traitement précoce et ciblé. <p>Dans la première partie de ce mémoire, nous avons étudié la place de l’acide tranexamique, agent antifibrinolytique, dans la prévention de la fibrinolyse chez les enfants bénéficiant d’une chirurgie cardiaque avec CEC. Nous avons évalué les propriétés pharmacocinétiques et pharmacodynamiques de la molécule dans cette population particulière. Notre hypothèse étant que l’utilisation de schémas adaptés pourrait permettre d’optimaliser la balance bénéfice/risque de l’utilisation prophylactique de l’acide tranexamique. <p>Nous avons également développé un modèle expérimental susceptible d’améliorer la sensibilité des tests viscoélastiques pour la détection de la fibrinolyse et qui pourrait être utilisé pour estimer la concentration minimale d’acide tranexamique nécessaire pour inhiber la fibrinolyse. <p>Dans la seconde partie de ce mémoire, nous avons étudié l’importance de l’implémentation d’une prise en charge adaptée de la coagulopathie, en utilisant un algorithme défini en tenant compte des caractéristiques de la population cible. Si le ROTEM® s’avère être un outil important, son utilisation doit être limitée aux enfants qui présentent un saignement anormal afin de guider l’administration de produits hémostatiques. L’ensemble de nos travaux contribue à l’amélioration de nos connaissances dans la prise en charge de l’enfant à risque de saignement en période péri-opératoire de chirurgie cardiaque. / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

Doctorat en Sciences biomédicales et pharmaceutiques / info:eu-repo/semantics/nonPublished