Dermatoglyphs in congenital heart disease.

The palmar dermatoglyphs of 800 patients with anatomically proven congenital heart disease were compared with prints from 1000 controls. A review of the previous studies revealed major technical deficiencies, and the present study failed to confirm most of the previously reported positive findings. An overall increase in the incidence of hypothenar patterns was found, probably explaining the previous suggestion of increased atd angle in congenital heart disease. A large number of statistical comparisons inevitably produced a few 'significant' results, most of which were inconsistent in various ways. Two percent of cases were found to have rare epidermal ridge malformation, ridge dissociation. The nature of the relationship between this and congenital heart disease is obscure. Claims that there are diagnostically useful dermatoglyphic changes in congenital heart disease can be disregarded.     

Chromosome abnormalities in congenital heart disease

Refinements in cytogenetic techniques have promoted progress in understanding the role that chromosome abnormalities play in the cause of congenital heart disease. To determine if mutations at specific loci cause congenital heart disease, irrespective of the presence of other defects, and to estimate the prevalence of chromosome abnormalities in selected conotruncal cardiac defects, we reviewed retrospectively cytogenetic and clinical databases at St. Louis Children's Hospital. Patients with known 7q11.23 deletion (Williams syndrome), Ullrich-Turner syndrome (UTS), and most autosomal trisomies were excluded from this analysis. Two groups of patients were studied. Over a 6.5-year period, 57 patients with chromosomal abnormalities and congenital heart disease were identified. Of these, 37 had 22q11 deletions; 5 had abnormalities of 8p; and 15 had several other chromosome abnormalities. The prevalence of chromosome abnormalities in selected conotruncal or aortic arch defects was estimated by analysis of a subgroup of patients from a recent 22-month period. Chromosome abnormalities were present in 12% of patients with tetralogy of Fallot, 26% in tetralogy of Fallot/pulmonary atresia, 44% in interrupted aortic arch, 12% in truncus arteriosus, 5% in double outlet right ventricle, and 60% in absent pulmonary valve. We conclude that chromosome analysis should be considered in patients with certain cardiac defects. Specifically, fluorescent in situ hybridization (FISH) analysis of 22q11 is indicated in patients with conotruncal defects or interrupted aortic arch. High resolution analysis should include careful evaluation of the 8p region in patients with either conotruncal or endocardial cushion defects. Am. J. Med. Genet. 70:292–298, 1997. © 1997 Wiley-Liss, Inc.     

Fibrinogen metabolism in cyanoti congenital heart disease

The metabolism and in vivo kinetics of fibrinogen labelled with radioactive iodine was studied in children with cyanotic congenital heart disease. The patients had a significantly lowered plasma fibrinogen pool, shortened fibrinogen half-life and increased fractional catabolic rate of fibrinogen compared with healthy children. The average plasma fibrinogen and absolute catabolic rate of fibrinogen did not differ from control values. The shortened fibrinogen half-life together with the correcting effect of anticoagulation with heparin indicated that fibrinogen was consumed by chronic disseminated intravascular coagulation. Inhibition of the fibrinolytic system with epsilon-aminocaproic acid in three cyanotic patients had no influence on the fibrinogen half-life in two of them but resulted in its prolongation in one patient.     

The heart after surgery for congenital heart disease

The pathology of the heart following surgical correction for congenital cardiac defects has not been fully explored. This study is based on valvar aortic stenosis, atrioventricular septal defect, complete transposition of the great arteries, and Fallot's tetralogy. Emphasis has been put on preexistent gross pathology, with histological verification, and postoperative complications. Among patients with aortic valve stenosis preexistent anomalies dominated (left ventricular hypoplasia, mitral valve abnormalities, left ventricular endocardial fibroelastosis). The findings suggest that the cases represent an extreme within a spectrum and could explain the late postoperative dismal results in patients suffering from congenital left heart obstruction. In patients with atrioventricular septal defects the important pathology related predominantly to the operative procedure (injury to the atrioventricular bundle, patch dehiscence at the site of the atrioventricular node, inadequate repair of the left atrioventricular valve leaflets) and to pulmonary obstructive vascular disease. In complete transposition of the great arteries, with or without ventricular septal defects, technical problems dominated. Obstruction of the systemic and pulmonic venous pathways, atrial dysrhythmia, and tricuspid valve injury were the most serious complications following Mustard's procedure. The Rastelli-type procedure was complicated by degeneration and calcification of the porcine valve and crowding of the left ventricle. The arterial switch was complicated by abnormal origin and course of the left circumflex artery, which led to kinking and myocardial infarction. In Fallot's tetralogy surgical complications (injury to the atrioventricular bundle and the tricuspid valve) were the most important. The study discloses that the heart after surgery for congenital heart disease cannot be considered without taking preexistent pathology into account. Careful preoperative investigations are mandatory, since most anomalies could have been detected and, hence, might have changed the operative result.     

Assessment of neuron in congenital heart disease with heart failure

Pathological studies in five hearts from patients with congenital heart diseases have demonstrated that the number of neurons is similar to that found in normal controls. The number of neurons has been counted in a strip of right atrial wall between the venae cavae. The hearts were selected from a wide spectrum of the population, the youngest being 5-months old and the oldest 35 years old (mean age: 12 years); all were in failure. The neuronal counts are comparable to those found in a normal population of mean age 40 years.     

Molecular mechanisms of congenital heart disease

BackgroundCongenital heart disease (CHD) is the most common type of birth defect. Despite the many advances in our understanding of cardiac development and many genes related to cardiac development identified, the fundamental etiology for the majority of cases of congenital heart disease remains unknown.MethodsThis review summarizes normal cardiac development, outlines the recent discoveries of the genetic causes of CHD, and provides possible strategies for exploring them.ResultsCHD is a multifactorial complex disease, with environmental and genetic factors playing important roles. A number of causative genes of selected congenital heart defects and genetic syndromes have been found. The molecular mechanisms of CHD may include mutations in components of the cardiac gene network, altered haemodynamics, regulatory pathway of cardiac genes, micro-RNA dysfunction, epigenetics, adult congenital heart diseases, and so on.ConclusionsThe molecular basis of CHD is an exciting and rapidly evolving field. The continuing advances in the understanding of the molecular mechanisms of CHD will hopefully result in improved genetic counseling and care of affected individuals and their families.     

The state of congenital heart disease

In this special issue of the American Journal of Medical Genetics Part C, we focus on the “State of Congenital Heart Disease.” We anticipate that after viewing this journal, the reader will be up‐to‐date on the epidemiology of congenital heart disease (CHD), the genetic basis of CHD, ethical concerns, and the global impact of CHD. And most importantly, we are confident that this special issue conveys the message that CHD is complex and that much work is still needed in genetic and genomic research.     

Postoperative pathology of congenital heart disease

The evaluation of congenitally malformed hearts that have been subjected to operative and nonoperative interventions includes not only a categorization of the underlying anomalies and various procedures but also an assessment of interventional complications, postprocedural changes in chamber, valvular, and vascular sizes, presence of ischemia or fibrosis, presence of cardiac or extracardiac infections, and evidence of regression or progression of hypertensive pulmonary vascular disease. Input from clinicians or surgeons may be helpful, but biases should be avoided. Referral of cardiopulmonary specimens to experienced pathologists may also be considered.     

Consanguinity and congenital heart disease in Saudi Arabia

First-cousin marriage may be a significant risk factor for specific types of congenital heart disease in a consanguineous population. Inbreeding studies suggest an autosomal recessive component in the cause of some congenital heart defects. We studied a large sample of patients with structural congenital heart defects (CHD) identified through the Congenital Heart Disease Registry at King Faisal Specialist Hospital in Riyadh, Saudi Arabia. After exclusions of chromosome abnormalities and non-participation, data were collected on 891 consecutive patients who were registered between January and August, 1998. Data on first-cousin consanguinity and type of CHD diagnosis were collected. A z test of proportions was used to determine the association between consanguinity and subtypes of CHD. Data indicate that the proportion of first cousins in the CHD sample is higher than the proportion in the general population, supporting a hypothesis of autosomal recessive gene involvement in congenital heart disease. When subgroups of CHD were analyzed, first-cousin consanguinity was significantly associated with ventricular septal defect (VSD), atrial septal defect (ASD), atrioventricular septal defect (AVSD), pulmonary stenosis (PS), and pulmonary atresia (PA). There was no relationship between consanguinity and tetralogy of Fallot (TOF), tricuspid atresia (TA), aortic stenosis (AS), co-arctation of the aorta (CoA), and patent ductus arteriosus (PDA). Thus, in a population with a high degree of inbreeding, consanguinity may exacerbate underlying genetic risk factors, particularly in the offspring of first cousins. There may be a recessive component in the causation of some cardiac defects. Copyright Wiley-Liss. Inc.     

Heartbeat sensitivity in adults with congenital heart disease

This study tested the hypothesis that patients with a congenital heart disease are sensitive regarding heartbeat perception, reflected in enhanced attention for heartbeat, estimation of own heart rate, and a vulnerability to become anxious by listening to heartbeat sounds. Twenty adults with a congenital heart disease, and 20 healthy controls conducted 3 experimental tasks: a concentration task during distraction by heartbeat sounds, own heart rate estimation, and exposure to different patterns of heartbeat sounds. The results showed that patients were more distracted by heartbeat, and were also worse at estimating heart rate than controls. However, heartbeat sounds did not evoke anxiety. In conclusion, patients with a congenital heart disease may differ from controls in heartbeat perception, but there was no support for obsessive monitoring for heartbeat or excessive reactions to heartbeat sounds.     

Other genomic disorders and congenital heart disease

Congenital heart disease (CHD) is the common birth defect worldwide. Despite its recognized burden on public health, the etiology in the vast majority of individuals remains unknown. Chromosomal abnormality plays an important role, frequently observed as large cytogenetically visible rearrangement or small submicroscopic structural variation in the genome. Several genomic disorders are now recognized that are increasingly responsible for CHD with variable penetrance. Single gene disorders, epigenetic alterations, and environmental etiologies are also significant contributors. Our understanding of the genetic basis of CHD has increased exponentially with the escalating use of next generation sequencing to identify ever so small submicroscopic genomic imbalances at the level of coding exons in CHD. This review focuses on genomic disorders other than 22q11.2 deletion, that are major players in the etiology of human cardiac malformations.     

The genetics of isolated congenital heart disease

The genetic mechanisms underlying congenital heart disease (CHD) are complex and remain incompletely understood. The majority of patients with CHD have an isolated heart defect without other organ system involvement, but the genetic basis of isolated CHD has been even more difficult to elucidate compared to syndromic CHD. Our understanding of the genetics of isolated CHD is advancing in large part due to advances in next generation sequencing, and the list of genes associated with CHD is rapidly expanding. Variants in hundreds of genes have been identified that may cause or contribute to CHD, but a genetic cause can still only be identified in about 20–30% of patients. Identifying a genetic cause for CHD can have an impact on clinical outcomes and prognosis and thus it is important for clinicians to understand when and what to test in patients with isolated CHD. This chapter reviews some of the known genetic mechanisms that contribute to isolated inherited and sporadic CHD as well as recommendations for evaluation and genetic testing in patients with isolated CHD.     

Fetal surgery for congenital heart disease.

Certain congenital heart defects, which present at birth as complex morphologic defects, are actually the result of a relatively simple primary lesion and the subsequent acquired development of a complex secondary lesion during gestation. Moreover, fetal heart approach during gestation can prevent simple cardiac lesions from such development. Specific structural lesions can be diagnosed before 12 weeks of gestation by transvaginal fetal echocardiography, and animal experiments have shown that direct or indirect fetal cardiac approach and fetal cardiac bypass are technically feasible. A number of fetal bypass models have resulted in long-term survivors, with for example, the delivery of normal lambs at full-term gestation. Also, successful full-term delivery has been obtained after fetal cardiac intervention. The success of fetal cardiac bypass was accomplished by the use of total spinal anesthesia and the administration of indomethacin. Moreover, a 42 % long-term survival after fetal cardiopulmonary bypass in a fetal lamb model has been reported. Maternal risk related to fetal bypass should be considered carefully alongside fetal risks and benefits. Most fetal malformations do not directly threaten maternal health, yet the procedures required to address fetal malformations can produce significant maternal risk and discomfort and subsequent pregnancies may be jeopardized. Further investigation of maternal outcome is required. Deep exploration of fetal and maternal pathophysiologic responses to intervention and comprehensive investigation is required to overcome current limitations, and should precede clinical trials as many problems remain to be solved before these techniques can be applied to human beings.