Exercise training after cardiac transplantation

During the last decade, cardiac transplantation has become the accepted form of treatment for selected patients with end-stage heart disease, which usually results from dilated cardiomyopathy or coronary artery disease. Although 5-yr survival is currently 85%, patients have complicated courses after surgery, with an ever present risk of infection and graft rejection. Because of physical inactivity and severe limitation of cardiac output preoperatively, these deconditioned patients are excellent candidates for medically supervised rehabilitative exercise training programs. Denervation of the myocardium, which occurs with cardiac transplantation, results in a loss of autonomic nervous system modulation of cardiac output, with reliance on circulating catecholamines and with a delayed heart rate and cardiac output response to the onset of exercise. Oxygen uptake kinetics are prolonged, and maximal oxygen uptake is reduced. Additional abnormalities in cardiac and pulmonary artery pressures and in ventilation during exercise have been described. The literature contains seven studies concerning the effects of exercise training in cardiac transplant recipients. Benefits resulting from training include increases in maximal oxygen uptake, peak exercise power output, anaerobic threshold, and lean body mass, reduced perceived exertion, heart rate, and blood pressure during submaximal exercise, and a lowered resting heart rate and blood pressure. There are no data to suggest that exercise training alters the incidence of infection or rejection or improves longevity or return to pre-illness lifestyle.     

Accuracy of fetal echocardiography

The reliability of prenatal ultrasound (US) for the detection of structural heart defects was investigated in a consecutive population of patients referred for prenatal US. Twenty-eight of 49 fetuses (57%) shown to have one or more heart defects with physical examination or autopsy were found to have congenital heart disease with prenatal US. There were 66 cardiac defects in 49 fetuses, 33 of which were entirely or partly identified (50%). Defects correctly diagnosed included hypoplasia of either ventricle, common atrioventricular canal, tetralogy of Fallot, transposition of the great vessels, and Ebstein anomaly. Defects rarely diagnosed correctly included semilunar valve stenosis, total anomalous pulmonary venous drainage, coarctation of the aorta, pulmonic atresia, atrioseptal defect, and ventricular septal defect. Many types of heart defects can be diagnosed accurately with prenatal US in a general population of patients not at high risk for congenital heart disease. Some lesions, however, were difficult to detect.     

Athletic Performance in Children With Cardiovascular Problems

The effects of physical training include cardiovascular and specific muscle adaptation, decreased resting heart rate, and increased cardiac size, stroke volume, maximum cardiac output, blood volume, vagal tone, and maximum breathing capacity. Young athletes with heart disease can generally participate in sports, but there is a wide spectrum of ability among them. The treadmill exercise test should be used to establish exercise norms. Children with severe mitral stenosis, aortic stenosis, idiopathic hypertrophic subaortic stenosis, active myocarditis, pulmonary hypertension, and significant arrhythmias should not participate in strenuous sports. Others with cardiac problems should be encouraged to participate for enjoyment rather than winning.     

Double outlet right ventricle presenting in an adult woman: a case report

Double outlet right ventricle (DORV) is a congenital cardiac malformation that occurs in 1%-3% of individuals with congenital heart defects. Cardiac magnetic resonance imaging (MRI) may play an important role in the anatomy of the ventricular septal defect, functional status of both ventricles, and in identifying any residual stenosis or regurgitation or coexistent anomalies. Here, we present a case of a 28-years-old woman who came to our emergency department with shortness of breath. The patient felt shortness of breath on exertion and improved with rest. Clinical examination showed no abnormalities except low oxygen saturation of 65%. After echocardiography and cardiac MRI were done, it was concluded that she had a double outlet right ventricle with peri membranous ventricular septal defect (VSD), pulmonary hypertension, and pericardial effusion. This study highlights the role of cardiac MRI in assessing DORV.     

婴儿先天性心脏病合并肺动脉高压的外科治疗

目的:总结婴儿先天性心脏病合并肺动脉高压的外科治疗和围术期处理的经验。方法:2004年1月～2006年6月共手术治疗婴儿先天性心脏病合并肺动脉高压患者72例,男性45例,女性27例;年龄2个月～1岁,平均(7.3±2.8)月,体重3.5～9.2kg,平均(6.2±3.6)kg。术前肺动脉收缩压为47.4～89.2mmHg,平均(64.3±7.6)mmHg;动脉血氧饱和度81%～98%。结果:手术死亡3例(4.17%)。主要并发症有肺动脉高压危象、低心输出量综合症、肺不张、张力性气胸、呼吸机相关肺炎、血源性感染,呼吸衰竭等。死亡原因:肺动脉高压危象2例,低心输出量综合症1例。术后SaO287%～98%。随访6个月～2年,无晚期死亡,余患者心功能较术前改善。结论:肺动脉高压危象和低心输出量综合症是婴儿先天性心脏病合并肺动脉高压患者术后的主要并发症和死亡原因,早期手术及搞好围术期的处理是提高生存率的关键。     

Stenotic lesions of pulmonary arteries: imaging evaluation using multidetector computed tomography angiography

Stenotic lesions of the pulmonary arteries can be congenital or acquired. Different etiologies may affect the pulmonary arteries, unilaterally or bilaterally, at different levels. The clinical scenario, age of presentation and the precipitating event may provide clues to the underlying etiology. Diagnosis is important as these lesions may have hemodynamic and clinical consequences. Multidetector computed tomography angiography allows for accurate depiction of these lesions along with a comprehensive assessment of the pulmonary arterial wall, intra- or extraluminal involvement, associated cardiac or extracardiac anomalies, effects secondary to pulmonary stenosis on the cardiac chambers as well as associated causative or resultant lung parenchymal changes.     

婴幼儿先天性心脏病外科治疗248例临床分析

目的:总结婴幼儿先天性心脏病外科治疗经验。方法:对248例<36月婴幼儿先心病外科手术治疗资料就诊断、临床特点、并发症及治疗结果进行回顾性分析。结果:婴幼儿先心病以室间隔缺损和法洛四联症为最常见,常合并其他畸形;年龄<12月组死亡率明显高于年龄24~36月组(P<0.05);体重<10 kg死亡率高于体重>10 kg者相差显著(P<0.01)。死亡原因以低心排出量综合征和呼吸衰竭最常见(78.9%)。结论:重危婴幼儿先心病应早期外科手术治疗,要严格手术适应症和时机,加强围手术期处理。     

非体外循环下全腔静脉-肺动脉连接术治疗复杂先天性心脏病16例分析

目的总结非体外循环下全腔静脉-肺动脉连接术（TCPC）治疗复杂先天性心脏病的临床经验。方法回顾性分析我院2006～2010年接受TCPC的16例复杂先天性心脏畸形患者,包括三尖瓣闭锁9例（其中1例为双向Glenn术后5年）,完全性大动脉转位合并房窒间隔缺损、肺动脉瓣狭窄4例,右室双出口伴其他畸形2例,单心室1例,均采用非体外循环下手术。结果术后无1例死亡,均痊愈出院,3例术后出现大量胸腔积液,经积极处理后恢复。所有患者症状消失,无明显发绀．经皮血氧饱和度达到89％～97％。恢复良好。结论TCPC方法简便易行,在严格掌握手术适应证、手术技巧及加强术后并发症防治的情况下,TCPC治疗复杂型先天性心脏病可取得良好的手术效果。     

Two-dimensional echocardiography and its influence on cardiac catheterization

Successful management of congenital heart disease requires complete anatomic definition and timely surgical intervention. Preoperative anatomic detail is enhanced by coordination of different imaging disciplines. Precatheterization cardiac ultrasound avoids unnecessary catheter manipulation, excess radiation and reduces contrast volume. Detailed noninvasive imaging, coupled with an understanding of the natural history and surgical alternatives, obviate the need for preoperative cardiac catheterization in selected lesions. Cardiovascular anomalies which, in a well defined set of circumstances, may be exclusively managed by twodimensional echocardiography include sinus venosus and secundum type interatrial septal defects, severe aortic stenosis in infancy, and hypoplastic left heart syndrome. The “well defined set of circumstances” are particular to each lesion and must include the patient's history, physical examination, electrocardiogram, and chest X-ray. Definitive management of a cardiovascular anomaly entails consideration of the relative superiority and cost benefit advantages of the different imaging disciplines.     

Pulmonary blood volume: Analysis during exercise in patients with left ventricular dysfunction

Recent reports have demonstrated substantial increases in pulmonary activity during radionuclide stress exercise studies in patients with coronary heart disease. These studies have shown that the degree of the increase reflected the severity of the underlying disease. We studied the effects of supine exercise on systolic function and pulmonary activity in ten normal control subjects and 20 patients with congestive cardiomyopathy (12 ischemic and 8 idiopathic). Ejection fraction rose in the normals (P<0.001), end-diastolic volume increased slightly but significantly (P<0.05), and pulmonary activity rose by less than 16%, (mean 10%) while cardiac output increased by 162%. On the other hand, the myopathy patients demonstrated a small increase in cardiac output, (+49%) with a more substantial increase in pulmonary activity (+25%, P<0.05 vs normals). In these patients, ejection fraction did not change during exercise, while end-diastolic and end-systolic volumes rose. In the myopathy patients, the cause for an increase in cardiac output was a rise in heart rate, with little change in stroke volume. We conclude that pulmonary activity rises in myopathy patients to a greater extent than in normal controls. This probably reflects the greater elevation in filling pressures these patients need to maintain forward cardiac output.     

Cardiac magnetic resonance imaging of congenital heart defects in adults

The study of congenital cardiopathies (CC) is one of the most clearly established indications of cardiac magnetic resonance imaging (CMRI). Different sequences, including anatomic, functional, flow (phase contrast), and 3D angiographic sequences, enable the diagnosis, treatment planning, and follow-up of these conditions. CMRI allows the anatomy, function, and alterations of flow in these cardiopathies to be evaluated in a single examination. Three-dimensional MR angiography enables the study of the great vessels and the anomalies associated to congenital heart defects in adults. This article describes an examination protocol and provides examples of MR images of the most common CC in adults: atrial septal defect, interventricular communication, atrioventricular canal, tetralogy of Fallot, transposition of the great arteries, congenitally corrected transposition of the great arteries, bicuspid aortic valve, subaortic stenosis, aortic coarctation, and Ebstein's anomaly.     

增强MR血管造影在儿童先天性心脏病诊断中的应用

目的：评价儿童先天性心脏病（简称先心病）患者MRI检查，特别是增强磁共振血管造影术（CE－MRA）的诊断价值与不足。方法：300例儿童先天性患者作CE－MRA检查，其中173例228个心内结构异常和105个心外大血管异常已经手术证实，并与MRI及CE－MRA诊断结果作对照。结果：在228个手术证实的心内结构异常（主要为间隔缺损与瓣膜病变）中，196个诊断正确（86．0％）；在105个心外大血管异常中，101个诊断正确（96．2％）。结论：对心外大血管畸形MRI及CE－MRA有很高的诊断价值，CE－MRA是对先尽病最有价值的扫描方法之一。     

Exercise and heart transplantation. A review.

Results of heart transplantation as therapy for end-stage cardiac diseases are encouraging not only because of actuarial survival curves but also because of the recovered quality of life for the heart transplant recipient. Although heart transplantation drastically improves the physical capacity of the patients, heart recipients still have a reduced maximal aerobic capacity compared to healthy people. Altered resting and exercise haemodynamics, due to cardiac denervation, are a common finding after orthotopic heart transplantation: increases in heart rate and stroke volume at exercise are first linked with the augmented venous return and later with the increased plasmatic nor-adrenaline level. Maximal heart rate and stroke volume are both reduced when compared to innervated heart. Reduced cardiac output response to exercise therefore results in early anaerobic metabolism, acidosis, hyperventilation and diminished physical capacity. In spite of an altered ventilatory adaptation to exercise, characterised by hyperpnoea in most transplant patients, ventilation is not the limiting factor for exercise in heart recipients without associated obstructive pulmonary disease. Endurance training restores lean tissue, decreases submaximal minute ventilation, increases peak work output, maximal ventilation and peak heart rate. Guidelines for prescribing exercise are not yet standardised due to the limited number of studies on a sufficient cohort of heart recipients. Nevertheless, recommendations similar to those used for persons with coronary heart disease, with modifications due to the denervated heart, seem to be used. The cardiocirculatory and pulmonary capacity of heart transplant recipients allow them to undertake endurance sports activities such as walking, jogging, cycling and swimming, and these should be encouraged.     

Spectrum of changes on cardiac magnetic resonance in repaired tetralogy of Fallot: Imaging according to surgical considerations

Imaging of repaired tetralogy of Fallot (TOF) is one of the common indications for cardiac magnetic resonance (CMR) examinations. With advances in CMR imaging techniques like phase contrast imaging and functional imaging, it has superseded investigations like echocardiography for anatomical and functional assessment of the pathophysiological changes in repaired TOF. Common repair procedures for TOF include infundibulectomy, transannular patch repair and right ventricle to pulmonary artery (RV-PA) conduit. While each of these procedures cause dynamic changes in heart and pulmonary arteries resulting in some expected imaging findings, CMR also helps in diagnosing the complications associated with these repair procedures like pulmonary stenosis, right ventricular outflow tract aneurysm, pulmonary regurgitation, RV-PA conduit stenosis, tricuspid regurgitation, right ventricular failure, and residual ventricular septal defects. Hence, it is imperative for a radiologist to be familiar with the expected changes on CMR in repaired TOF along with some of the common complications that may be encountered on imaging in such patients.     

Complete noninverted transposition of the great arteries

Thirty cases of complete noninverted transposition of the great arteries (TGA) were studied to determine the roentgen characteristics of this disorder revealed on conventional chest radiographs. Five of the patients had associated pulmonary stenosis. Increasing cardiomegaly, an “egg-on-side” contour and pulmonary plethora in an infant cyanotic from birth strongly suggest the diagnosis of TGA without pulmonic stenosis. In TGA with pulmonic stenosis, the heart is normal in size and contour and pulmonary oligemia is usually present.

Although other congenital cardiac abnormalities may present similar roentgen findings, the radiologist must suggest the possibility of TGA when these roentgen characteristics are present since the diagnosis is readily established angiographically and early operative intervention can produce significant palliation and prolonged survival.     

先天性主动脉窦瘤的外科治疗

目的总结先天性主动脉窦瘤外科治疗经验。方法先天性主动脉窦瘤(CASV)28例,其中合并室间隔缺损18例(64%)、主动脉瓣脱垂7例(25%)。行窦瘤切除修补术11例,窦瘤切除加室缺修补10例,窦瘤切除加主动脉瓣成形2例、主动脉瓣替换5例。结果全组无手术死亡、无残余分流。结论心脏超声对CASV诊断准确率高。窦瘤破裂对心功能影响迅速而严重且预后较差。故一经确诊,宜尽早手术治疗,以及时纠正血流动力学紊乱。窦瘤破口直径>1.0 cm者宜用补片修补。缝合或修补窦瘤时进针方向要与主动脉长轴平行,并通过主动脉瓣环及其上缘的主动脉壁,以防止窦瘤复发或残余分流。     

128层MSCT虚拟仿真内镜技术在婴幼儿先天性心脏病的应用

目的:探讨128层MSCT虚拟仿真内镜技术(VE)对婴幼儿先天性心脏病的诊断价值.方法:回顾性分析67例先天性心脏病患儿128层螺旋CT和经胸壁超声心动图(TTE)资料,并与手术结果作对照.采用5分单盲法评价VE图像质量,比较心房心室和大血管的差异,建立VE飞行路径规划.结果:VE诊断主要心脏结构异常的总符合率51.7...     

Flexibility and Strength Measures in Children Participating in a Cardiac Rehabilitation Exercise Program

In brief: The purpose of this study was to evaluate the effects of a structured rehabilitation program on the strength and flexibility of children with surgically corrected congenital heart disease. Twelve children (eight boys, four girls) participated in one-hour exercise classes, two times per week for 12 weeks. Results showed minimal changes in upper extremity strength, but lower extremity strength improved 10% and 5% on the right and left sides, respectively. Flexibility improved about 25% in the lower extremities. Improvement was also noted in neck flexion, hip and oblique rotation, hamstring and low back stretch, and heel cord stretch. These findings indicate that this type of program can improve strength and flexibility in children who have undergone complex heart surgery and may help them achieve a more normal life-style.     

Validity of CO2-rebreathing cardiac output during rest and exercise in young adults

To validate the CO2-rebreathing method ( Defare 's method) for estimating cardiac output in children and young adults, measurements were compared to thermodilution ( TDCO ) cardiac output in 16 subjects (age 7-19 yr) with congenital heart disease. Data were collected at rest (N = 11) and during 4-min stages of supine bicycle exercise (N = 13). Estimated arterial-venous (-v-a)CO2 content differences related linearly to the measured CO2 content difference (Y = 0. 29X + 2.47, r = 0.65, P less than 0.001). With this (v-a)CO2 difference correction for all patients (N = 16), the correlation between CO2-rebreathing cardiac output and the TDCO was r = 0.87 (SEE = +/- 1.8 l X min-1). The correlation was higher for exercise (r = 0.81) than for rest (r = 0.65). We conclude that the CO2-rebreathing method, with a (v-a)CO2 content difference adjustment, is a simple, noninvasive technique providing estimates of cardiac output in children and young adults with congenital heart disease. Individual estimates should be treated with caution, especially when used for clinical evaluations.