Ebstein's anomaly - review of a multifaceted congenital cardiac condition

Ebstein's Anomaly: An Unanticipated Differential Diagnosis of Egg-on-Stick Appearance and the Diagnostic Dilemma

Patient: Female, 42-year-old

Final Diagnosis: Ebstein’s anomaly

Symptoms: Dyspnoea on exertion • early satiety • fatigue • orthopnea • PND • progressive abdominal swelling • weigh loss

Medication: —

Clinical Procedure: Paracentesis

Specialty: Cardiology

Trisomy 21 and Ebstein Anomaly: Diagnosis and Prognosis of a Rare Association

Trisomy 21 is considered the most common chromosomal aneuploidy, and congenital heart disease (CHD) is highly prevalent and relevant to the morbidity and mortality of these patients. Ebstein anomaly (EA) is a rare CHD characterized by tricuspid valve dysplasia with inferior septal leaflet displacement. Herein, we described a patient with trisomy 21 who presented with EA and discuss the association between the two conditions based on a literature review. We conclude that the concomitant occurrence of both conditions is considered to be rare. These individuals are most frequently diagnosed during birth and childhood, and they usually have a good prognosis, as observed with our patient and is typical for EA patients in general. However, it is important to be aware that electrophysiologic anomalies may also be present.

A simple measure of the extent of Ebstein valve rotation with cardiovascular magnetic resonance gives a practical guide to feasibility of surgical cone reconstruction

BACKGROUND

Once surgical management is indicated, variation of Ebstein valve morphology affects surgical strategy. This study explored practical, easily measureable, cardiovascular magnetic resonance (CMR)-derived attributes that may contribute to the complexity and risk of cone reconstruction.

METHODS

A retrospective assessment was performed of Ebstein anomaly patients older than 12 years age, with pre-operative CMR, undergoing cone surgical reconstruction by one surgeon. In addition to clinical data, the CMR-derived Ebstein valve rotation angle (EVRA), area ratios of chamber size, indexed functional RV (RVEDVi) and left ventricular (LV) volumes, tricuspid valve regurgitant fraction (TR%) and other valve attributes were related to early surgical outcome; including death, significant residual TR% or breakdown of repair.

RESULTS

Of 26 operated patients older than 12 years age, since program start, 20 had pre-op CMR and underwent surgery at median (range) age 20 (14-57) years. TR% was improved in all patients. Four of the 20 CMR patients (20%) experienced early surgical dehiscence of the paravalve tissue, with cone-shaped tricuspid valve intact; one of whom died. A larger EVRA correlated with Carpentier category and was significantly related to dehiscence. If EVRA >60o, relative risk of dehiscence was 3.2 (CI 1.3-4.9, p = 0.03). Those with dehiscence had thickened, more tethered anterior leaflet edges (RR 17, CI 3-100, p < 0.01), smaller pre-operative functional RVEDVi; (132 vs 177 mL/m2, p = 0.04), and were older (median 38 vs 19 years, p = 0.01). TR %, chamber area ratios and LV parameters were not different.

CONCLUSIONS

Comprehensive CMR assessment characterizes patients prior to cone surgical reconstruction of Ebstein anomaly. Pragmatic observation of larger EVRA, smaller RVEDVi and leaflet thickening, suggests risk of repair tension and dehiscence, and may require specific modification of cone surgical technique, such as leaflet augmentation.

Potential risk factors for Ebstein anomaly, National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Ebstein anomaly is a rare congenital heart defect (CHD) that, when severe, requires corrective surgery or other catheter-based intervention in the first year of life. Due to its rarity, risk factors for Ebstein anomaly remain largely unknown. Using national data, we examined 18 potential risk factors for Ebstein anomaly.

METHODS

Using 1997-2011 data from the National Birth Defects Prevention Study, a population-based case-control study, we calculated crude and adjusted odds ratios and 95% confidence intervals for paternal age, maternal socio-demographics, reproductive history, and modifiable risk factors, and infant characteristics reported by mothers of 135 Ebstein anomaly cases and 11,829 controls.

RESULTS

Mothers of Ebstein anomaly cases had 4.1 (95% confidence interval: 1.8, 9.5) times the odds of reporting a family history of CHD compared with mothers of controls. Ebstein anomaly was associated with maternal second-hand cigarette smoke exposure at home (odds ratio = 2.2 [95% confidence interval: 1.1, 4.4]), but not maternal cigarette smoking (odds ratio = 1.3 [95% confidence interval: 0.8, 2.1]). Odds were elevated, but the 95% confidence interval included 1.0, for maternal marijuana use (odds ratio = 1.8 [95% confidence interval: 0.9, 3.8]) and paternal age ≥40 years at delivery (odds ratio = 1.9 [95% confidence interval: 1.0, 3.5]).

CONCLUSIONS

Maternal exposure to second-hand cigarette smoke at home and a family history of CHD were associated with elevated odds of Ebstein anomaly. Genetic analyses could clarify the potential heritability of Ebstein anomaly.

Cardiovascular magnetic resonance evidence of myocardial fibrosis and its clinical significance in adolescent and adult patients with Ebstein's anomaly

BACKGROUND

Myocardial fibrosis is a common pathophysiological process that is related to ventricular remodeling in congenital heart disease. However, the presence, characteristics, and clinical significance of myocardial fibrosis in Ebstein's anomaly have not been fully investigated. This study aimed to evaluate myocardial fibrosis using cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) and T1 mapping techniques, and to explore the significance of myocardial fibrosis in adolescent and adult patients with Ebstein's anomaly.

METHODS

Forty-four consecutive patients with unrepaired Ebstein's anomaly (34.0 ± 16.2 years; 18 males), and an equal number of age- and gender-matched controls, were included. A comprehensive CMR protocol consisted of cine, LGE, and T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequences were performed. Ventricular functional parameters, native T1, extracellular volume (ECV), and LGE were analyzed. Associations between myocardial fibrosis and disease severity, ventricular function, and NYHA classification were analyzed.

RESULTS

LGE was found in 10 (22.7%) patients. Typical LGE in Ebstein's anomaly was located in the endocardium of the septum within the right ventricle (RV). The LV ECV of Ebstein's anomaly were significantly higher than those of the controls (30.0 ± 3.8% vs. 25.3 ± 2.3%, P < 0.001). An increased ECV was found to be independent of the existence of LGE. Positive LGE or higher ECV (≥30%) was associated with larger fRV volume, aRV volume, increased disease severity, and worse NYHA functional class. In addition, ECV was significantly correlated with the LV ejection fraction (P <  0.001).

CONCLUSIONS

Both focal and diffuse myocardial fibrosis were observed in adolescent and adult patients with Ebstein's anomaly. Increased diffuse fibrosis is associated with worse LV function, increased Ebstein's severity, and worse clinical status.

Copy number variants in Ebstein anomaly

Background

Ebstein anomaly (EA) is a rare congenital defect characterized by apical displacement of the septal tricuspid leaflets and atrialization of the right ventricle. The etiology of EA is unclear; however, recurrence in families and the association of EA with genetic syndromes and copy number variants (CNVs) suggest a genetic component.

Objective

We performed a population-based study to search for recurrent and novel CNVs in a previously unreported set of EA cases.

Methods

We genotyped 60 EA cases identified from all live births (2,891,076) from selected California counties (1991–2010) using the Illumina HumanOmni2.5–8 array. We identified 38 candidate CNVs in 28 (46%) cases and prioritized and validated 11 CNVs based on the genes included.

Results

Five CNVs (41%) overlapped or were close to genes involved in early myocardial development, including NODAL, PDLIM5, SIX1, ASF1A and FGF12. We also replicated a previous association of EA with CNVs at 1p34.1 and AKAP12. Finally, we identified four CNVs overlapping or in close proximity to the transcription factors HES3, TRIM71, CUX1 and EIF4EBP2.

Conclusions

This study supports the relationship of genetic factors to EA and demonstrates that defects in cardiomyocytes and myocardium differentiation may play a role. Abnormal differentiation of cardiomyocytes and how genetic factors contribute should be examined for their association with EA.

The modified cone reconstruction in the treatment of Ebstein's anomaly: Case reports

RATIONALE

To investigate the early and mid-term clinical outcomes of the modified cone reconstruction in the treatment of Ebstein's anomaly (EA) which provide appropriate surgical treatment for clinical and reduce the incidence of re-operation and valve replacement.

PATIENT CONCERNS

Clinical data of 18 consecutive patients with EA in our hospital between May 2008 and August 2015 were analyzed retrospectively. All patients were diagnosed by echocardiography. Among these patients, according to New York Heart Association functional grade, there were 12 patients with grade II cardiac function and 6 patients with grade III. All patients had severe tricuspid regurgitation grade.

DIAGNOSES

All patients were diagnosed EA. One case was with acute arterial embolism and amputation of left lower extremity caused by paradoxical embolism of combined secundum atrial septal defect.

INTERVENTIONS

The modified cone reconstruction in the treatment of EA of the tricuspid valve uses its own tissues to form not only central bloodstream, but also the coaption between 2 leaflets. For those patients whose anterior leaflet developed poor and smaller, the valve leaflet was widened by using autologous pericardial. For all patients, tricuspid annulus were reinforced by autologous pericardial. One case was combined with double-orifice technique due to postoperative poor closure of the tricuspid valve.

OUTCOMES

There were 2 cases with arrhythmia, and they returned to normal after medication. The rest patients recovered smoothly with no death. Review of echocardiography: 1 patient with moderate regurgitation, the rest of patients' leaflets coapted well and had no tricuspid stenosis. All cases were followed up postoperatively for 9 to 38 months, and there were 14 patients with grade I cardiac function and 4 patients with grade II.

LESSONS

The early and mid-term clinical outcomes of the modified cone reconstruction in the treatment of EA were which can make leaflets coapt and had a strong antiregurgitation ability, reducing the incidence of re-operation, valve replacement, and postoperative mortality.

Intraoperative Transesophageal Echocardiography in the Operation of Ebstein's Anomaly: A Retrospective Study

Background:

Ebstein's anomaly (EA) has various spectrums in clinical and anatomic features. This study aimed to report the experience of two-dimensional intraoperative transesophageal echocardiography (2D-ITEE) during the EA surgery and to analyze the characteristics of the tricuspid valve (TV) by comparing the data from 2D-ITEE with the results from the surgery.

Methods:

2D-ITEE data of 164 patients with EA who were operated in the First Hospital of Tsinghua University between July 2004 and April 2014 were retrospectively analyzed in this study. 2D-ITEE was applied in all patients. Downward displacement distances were measured, and the numbers of downward displacement or absent leaflets were compared with that of the surgery and with that of the two-dimensional-transthoracic echocardiogram (2D-TTE). Data comparison was performed using the Chi-square test.

Results:

The anterior leaflet partial or total downward displacement was 37.76 ± 17.50 mm in 54 cases, absent in one patient; septal leaflet downward displacement was 29.07 ± 12.34 mm in 134 cases, absent in 17 cases; and posterior leaflet downward displacement was 43.18 ± 19.16 mm in 115 cases, absent in 34 cases. Statistically, there was no significant difference between the results from 2D-ITEE and that of 2D-TTE. The consistency rates of 2D-ITEE with operation for septal and posterior leaflets were 93.2% and 96.1%, respectively, while the rate for anterior was only 40.1%, which was significantly different. Color Doppler flow image showed severe regurgitation in 150 cases and moderate in 14 cases. After surgical correction, moderate regurgitation of TV was found in 58 cases with 2D-ITEE, repair was performed again until the effect was satisfied. No complication occurred relating to the use of 2D-ITEE.

Conclusions:

2D-ITEE could help diagnose anterior leaflet, evaluate the effect of TV repair, increase operational success rate, and reduce complication.

The Two Anomalies of Wilhelm Ebstein

The year 2016 was the 180th anniversary of Wilhelm Ebstein's birth and the 150th anniversary of his description of the congenital tricuspid valve malformation that came to be known as Ebstein anomaly. We present a brief history of the life and work of Dr. Wilhelm Ebstein. Despite his distinguished career, he is seemingly forgotten in his own birthplace. We include a review of the relevant historical medical literature.

Acute arterial embolism of left lower extremity caused by paradoxical embolism in Ebstein's anomaly: A case report

INTRODUCTION

Ebstein's anomaly is a benign and stable congenital heart disease for asymptomatic patients. Despite a low incidence of Ebstein's anomaly (EA), patients' quality of life can be badly affected by EA without positive surgical intervention. Especially EA is associated with other congenital heart disease, such as the atrial septal defect, patent foramen ovale, and arterial embolism exclude other reasons, it is often considered to be the consequence of paradoxical embolism, and surgical intervention must be conducted.

CASE REPORT

An 11-year-old girl falling off the bed suffered pain from left lower extremity. Echocardiographic evaluation revealed an EA, severe tricuspid regurgitation, and secundum atrial septal defect. Both left leg amputation and cardiac surgery were conducted after recovery. Under the condition of anesthesia cardiopulmonary bypass extracorporeal circulation, atrial septal defect repair and Cone reconstruction of the tricuspid valve were performed. Patient recovered well and left hospital smoothly.

DISCUSSION

EA is a rare and complex congenital cardiac malformation. There are about 80% to 90% of EA patients with combined atrial septal defect and patent foramen ovale. Sudden arterial occlusion is very rare especially in childhood. When thoracic roentgenoscopy, arterial blood gas analysis, coagulation test, and echocardiographic of lower extremity deep venous system are all normal, one should consider the possibility of a paradoxical embolism. If patients have the paradoxical embolism or worsening tricuspid regurgitation, the most suitable therapeutic regimen should be chosen according to patients' condition. With surgical techniques and methods renewed continuously, cone reconstruction of the tricuspid valve has been confirmed in clinical trials, which can use its own tissues to form not only central bloodstream, but also the coaption between leaflet and leaflet.

Genetic Variants in Isolated Ebstein Anomaly Implicated in Myocardial Development Pathways

Ebstein anomaly (EA) is a rare heart defect in which the tricuspid valve is malformed and displaced. The tricuspid valve abnormalities can lead to backflow of blood from the right ventricle to the right atrium, preventing proper circulation of blood to the lungs. Although the etiology of EA is largely unresolved, increased prevalence of EA in those with a family history of congenital heart disease suggests EA has a genetic component. Copy number variants (CNVs) are a major source of genetic variation and have been implicated in a range of congenital heart defect phenotypes. We performed a systematic, genome-wide search for CNVs in 47 isolated EA cases using genotyping microarrays. In addition, we used a custom HaloPlex panel to sequence three known EA genes and 47 candidate EA genes. We identified 35 candidate CNVs in 24 (51%) EA cases. Rare sequence variants in genes associated with cardiomyopathy were identified in 11 (23%) EA cases. Two CNVs near the transcriptional repressor HEY1, a member of the NOTCH signaling pathway, were identified in three unrelated cases. All other candidate CNVs were each identified in a single case. At least 11 of 35 candidate CNVs include genes involved in myocardial development or function, including multiple genes in the BMP signaling pathway. We identified enrichment of gene sets involved in histone modification and cardiomyocyte differentiation, supporting the involvement of the developing myocardium in the etiology of EA. Gene set enrichment analysis also identified ribosomal RNA processing, a potentially novel pathway of altered cardiac development in EA. Our results suggest an altered myocardial program may contribute to abnormal tricuspid valve development in EA. Future studies should investigate abnormal differentiation of cardiomyocytes as a potential etiological factor in EA.

Long-Term Results after Surgical Treatment of Ebstein's Anomaly: a 30-year Experience

BACKGROUND AND OBJECTIVES

The aim of the study is to evaluate the long-term results after a surgical repair of Ebstein's anomaly.

SUBJECTS AND METHODS

Forty-eight patients with Ebstein's anomaly who underwent open heart surgery between 1982 and 2013 were included. Median age at operation was 5.6 years (1 day-42.1 years). Forty-five patients (93.7%) demonstrated tricuspid valve (TV) regurgitation of less than moderate degree. When the patients were divided according to Carpentier's classification, types A, B, C, and D were 11, 21, 12, and 4 patients, respectively. Regarding the type of surgical treatment, bi-ventricular repair (n=38), one-and-a half ventricular repair (n=5), and single ventricle palliation (n=5) were performed. Of 38 patients who underwent a bi-ventricular repair, TV repairs were performed by Danielson's technique (n=20), Carpentier's technique (n=11), Cone repair (n=4), and TV annuloplasty (n=1). Two patients underwent TV replacement. Surgical treatment strategies were different according to Carpentier's types (p<0.001) and patient's age (p=0.022).

RESULTS

There were 2 in-hospital mortalities (4.2%; 1 neonate and 1 infant) and 2 late mortalities during follow-up. Freedom from recurrent TV regurgitation rates at 5, 10, and 15 years were 88.6%, 66.3%, 52.7%, respectively. TV regurgitation recurrence did not differ according to surgical method (p=0.800). Survival rates at 5, 10, and 20 years were 95.8%, 95.8%, and 85.6%, respectively, and freedom from reoperation rates at 5, 10, and 15 years were 85.9%, 68.0%, and 55.8%, respectively.

CONCLUSION

Surgical treatment strategies were decided according to Carpentier's type and patient's age. Overall survival and freedom from reoperation rates at 10 years were 95.8% and 68.0%, respectively. Approximately 25% of patients required a second operation for TV during the follow-up.

Illustrated Imaging Essay on Congenital Heart Diseases: Multimodality Approach Part III: Cyanotic Heart Diseases and Complex Congenital Anomalies

From the stand point of radiographic analysis most of the complex cyanotic congenital heart diseases (CHD), can be divided into those associated with decreased or increased pulmonary vascularity. Combination of a specific cardiac configuration and status of lung vasculature in a clinical context allows plain film diagnosis to be predicted in some CHD. Correlation of the position of the cardiac apex in relation to the visceral situs is an important information that can be obtained from the plain film. This information helps in gathering information about the atrio-ventricular, ventricular arterial concordance or discordance. Categorization of the cyanotic heart disease based on vascularity is presented below. Thorough understanding of cardiac anatomy by different imaging methods is essential in understanding and interpreting complex cardiac disease. Basic anatomical details and background for interpretation are provided in the previous parts of this presentation.

Maximizing the Effectiveness of Ablation for Arrhythmias in the Congenital Heart Patients

Arrhythmias are common in adults with congenital heart disease and account for a large proportion of hospitalizations. The complex anatomical heterogeneity, often in the presence of a delicate hemodynamic system, presents a significant electrophysiological challenge. This review outlines current clinical practice and advances in maximizing the effectiveness of ablation for arrhythmias in congenital heart patients.

[Congenital heart defects in adulthood : Supraventricular tachycardia]

Supraventricular tachycardia (SVT) based on congenital substrates, such as accessory pathways or dual atrioventricular nodal properties, occur with an increased probability linked to specific congenital heart defects (CHDs). In the literature, the association of Ebstein's anomaly with accessory pathways and with Mahaim fibers is most prominent. Compared with patients with otherwise normal hearts, the clinical relevance of SVT is typically more severe and therefore antiarrhythmia treatment is a necessity in many cases. Diagnostics, pharmaceutical treatment, and interventional therapy of SVT in patients with CHD are often demanding owing to anatomical, hemodynamic, and electro-anatomical peculiarities. The use of antiarrhythmic medication is often limited because of intolerable side effects and a lack of reliability in suppressing arrhythmia relapses in the long term. Within the last 15-20 years catheter ablation has thus become established as the first-choice treatment for SVT, even in patients with CHD. However, rates of success, recurrence, and risks are still inferior to those observed in patients with a normally functioning heart owing to the co-existence of vascular and cardiac anomalies, surgically created alterations, an unusual electro-anatomy, and lower tolerance to hemodynamic changes. Successful treatment in patients with CHDs and SVT requires a deep understanding and knowledge of all the disciplines discussed above and should only be practiced in dedicated centers, as patient numbers are small and therefore experience is limited.

Anesthetic challenges of decompressive craniotomy for the right frontal lobe abscess in a patient with Ebstein's anomaly: A rare case report

Ebstein's anomaly is a rare congenital heart disease characterized by downward displacement of the tricuspid valve, atrialization of right ventricle, enlarged right atrium with tricuspid regurgitation, or stenosis. It is often associated with atrial septal defect (ASD) or patent foramen ovale with right to left shunt. It has a varied clinical presentation and can manifest as cyanosis, ventricular, or supraventricular arrhythmias and recurrent episodes of congestive heart failure. We describe the anesthetic management of a female patient with Ebstein's anomaly who had right frontal lobe abscess due to paradoxical embolism for decompressive craniotomy.

An unusual ultrasonographic manifestation of a fetal Ebstein anomaly

An Ebstein anomaly is a rare congenital heart defect defined by an inferior displacement of the septal and posterior leaflets of the tricuspid valve from the tricuspid annulus. This anomaly shows various ultrasonographic manifestations, thus making the prenatal diagnosis sometimes difficult. We here report a rare case of an Ebstein anomaly which was prenatally suspected as the absence of the tricuspid valve with functional pulmonary atresia because of non-visible tricuspid leaflets on an echocardiograph at 24 weeks of gestation. An emergency cesarean section was performed at 35 weeks of gestation as fetal hydrops were seen on a follow-up scan. Postnatal surgery confirmed Ebstein anomaly type-D which demonstrates an almost complete atrialization of the right ventricle with the exception of a small and infundibular component. Because of its rarity, prenatal findings of a type-D Ebstein anomaly have not been reported previously. We suggest from this first such case report that this anomaly should be considered as a possible diagnosis when the tricuspid leaflets are not well visualized.

[Interventional treatment of tachyarrhythmia in children with congenital heart disease]

In children and adolescents with congenital heart disease (CHD) tachyarrhythmia occurs more frequently compared to patients with otherwise normal hearts. Arrhythmia substrates may be a natural part of certain congenital cardiac malformations or may result from long lasting myocardial deterioration as a result of CHD and/or cardiac surgery. Treatment of tachycardia is more frequently required even in early childhood, as the impact on quality of life, morbidity and mortality is higher due to an often reduced hemodynamic tolerance. Over the past 20 years interventional electrophysiology has been established as the therapy of choice for the majority of chronic or chronically recurrent tachycardia even in children with CHD. The success and risks of treatment are predominantly influenced by the individual expression of the cardiac anomaly and, if surgery has been performed, the highly variant postoperative anatomy. Introduction of 3D electroanatomical mapping systems together with modern cardiac imaging tools have significantly contributed to an improved understanding, particularly in postoperative tachycardia. Despite such progress, success rates are lower and recurrences are more frequent compared to patients without CHD. Complex and often multiple tachycardia courses account for the still limited performance as well as a frequently insufficient lesion formation with the use of radiofrequency current in the hypertrophic and fibrotic myocardium. Electrophysiology in children and adolescents, particularly if CHD is present, represents a highly specialized discipline requiring a high expertise in CHD, CHD surgery and cardiac electrophysiology and is ideally imbedded within an interdisciplinary cardiological and cardiosurgical setting.

Ablation of Arrhythmias in Patients with Adult Congenital Heart Disease

Arrhythmias in adults with congenital heart disease, most commonly related to previous surgical procedures, are a frequent comorbidity in this growing population thanks to the improved outcome of surgical techniques. Re-entrant circuits around areas of scarring and natural barriers, combined with abnormal haemodynamics and the underlying anatomy, are the most common cause for these arrhythmias. They are often poorly tolerated and medical treatment is frequently inadequate. In recent years, catheter ablation has emerged as a successful therapeutic option. New advanced techniques such as the use of modern three-dimensional (3D) navigation systems have contributed to better understanding of the arrhythmia mechanisms and higher success rates of the ablation procedures. In this article we briefly summarise the characteristics of the most common arrhythmias in this patient population and some key aspects in their treatment by catheter ablation.

Prevention of metabolic decompensation in an infant with mutase deficient methylmalonic aciduria undergoing cardiopulmonary bypass

BACKGROUND

Effects of circulatory arrest upon an inborn error of metabolism patient are unknown.

METHODS

A retrospective chart review was performed of outcome and biochemical parameters obtained during palliative cardiac surgery for a mutase-deficient methylmalonic aciduria patient with Ebstein's cardiac anomaly was performed.

RESULTS

The levels of ammonia, methylmalonic acid, free carnitine, and propionylcarnitine of the patient were improved. The patient survived surgery following institution of four metabolic treatment principles: 1) restriction of toxic substrate; 2) promotion of anabolism via administration of carbohydrate and lipid calories; 3) administration of detoxifying levocarnitine and sodium benzoate; and 4) cobalamin enzymatic co-factor administration. The patient died from post-operative dysrhythmia and was posthumously determined to have compound heterozygosity for mutations predicting severe, cobalamin non-responsive disease: c.322C>T/c.1233del3 (p.R108C/p.ΔI412).

CONCLUSION

Metabolic decompensation is preventable during cardiopulmonary bypass and cardioplegia using four principles of metabolic treatment.

Congenital Heart Defects in Adults : A Field Guide for Cardiologists

Advances in cardiology and cardiac surgery allow a large proportion of patients with congenital heart defects to survive into adulthood. These patients frequently develop complications characteristic of the defect or its treatment. Consequently, adult cardiologists participating in the care of these patients need a working knowledge of the more common defects. Occasionally, patients with congenital heart defects such as atrial septal defect, Ebstein anomaly or physiologically corrected transposition of the great arteries present for the first time in adulthood. More often patients previously treated in pediatric cardiology centers have transitioned to adult congenital heart disease centers for ongoing care. Some of the more important defects in this category are tetralogy of Fallot, transposition of the great arteries, functionally single ventricle defects, and coarctation. Through this field guide, we provide an overview of the anatomy of selected defects commonly seen in an adult congenital practice using pathology specimens and clinical imaging studies. In addition, we describe the physiology, clinical presentation to the adult cardiologist, possible complications, treatment options, and outcomes.

Xenopus: An emerging model for studying congenital heart disease

Congenital heart defects affect nearly 1% of all newborns and are a significant cause of infant death. Clinical studies have identified a number of congenital heart syndromes associated with mutations in genes that are involved in the complex process of cardiogenesis. The African clawed frog, Xenopus, has been instrumental in studies of vertebrate heart development and provides a valuable tool to investigate the molecular mechanisms underlying human congenital heart diseases. In this review, we discuss the methodologies that make Xenopus an ideal model system to investigate heart development and disease. We also outline congenital heart conditions linked to cardiac genes that have been well studied in Xenopus and describe some emerging technologies that will further aid in the study of these complex syndromes.

A Case of a Pulmonary Arteriovenous Malformation With Ebstein's Anomaly

A pulmonary arteriovenous malformation (PAVM) is a rare pulmonary vascular anomaly presenting as dyspnea or recurrent epistaxis. Ebstein's anomaly (EA), a congenital cardiac malformation, is also a rare condition. There have been no reports concerning the co-existence of PAVM with hereditary hemorrhagic telangiectasia (HHT) and EA. A 40-year-old woman was admitted with a 2-month history of increasing dyspnea and several years of recurrent epistaxis. On transthoracic echocardiography, she was diagnosed with EA and agreed to undergo surgical treatment. A chest CT angiography showed a 12-mm serpiginous vascular structure suspicious for a PAVM and a liver CT suggested HTT. Although it is unclear whether or not a concurrent PAVM and EA have an embryologic or genetic relationship, we report a case of a PAVM with EA. Further genetic and embryonic studies are needed to identify a possible relationship of the two medical conditions.

Philosopher, pediatrician, pathologist? John Locke's thoughts on Rhicketts and a missed case of Ebstein's anomaly

John Locke (1632-1704) is primarily remembered for his highly influential philosophical works regarded as the engine of the Enlightenment. It is less well known that Locke also was a highly regarded and influential physician. In 1666, Locke performed a postmortem examination of an 18-month-old child who had physical signs of rickets. Locke, a medical student at this time, attributed rickets as the cause of death. However, Locke described and recognized severe cardiac abnormality and speculated that right-to-left interatrial shunting was part of rickets. Locke's clearly described clinical history and postmortem findings are more consistent with a congenital cardiac malformation, an Ebstein's anomaly, in addition to the rickets. Locke did not consider this case as other than rickets. His opinion was not challenged when the case report was re-presented in the past half century. This article forces a reevaluation of the 17th-century understanding of infant cardiovascular physiology and pathology: Locke clearly gives one of the earliest descriptions of right-to-left shunting through the patent foramen ovale. It is unfortunate that Locke apparently did not discuss his postmortem findings with his contemporary Richard Lower (1631-1691), whose celebrated masterpiece on the heart, Tractatus de Corde, was published in 1669.

Severe Ebstein's anomaly can benefit from a small ventricular septal defect: two cases

Ebstein's anomaly is a rare congenital heart defect. Associated lesions are uncommon, and the mortality rates can be as high as 54% during the first month of life. Two cases of severe Ebstein's anomaly with ventricular septal defect are described. It is speculated that this rare association, allowing adequate forward pulmonary blood flow in the neonate, permitted the reported patients to survive the neonatal period, which is the most life-threatening time. The authors propose that the presence of a small ventricular septal defect can be beneficial for such patients, averting the need for surgery during early infancy when the risk is highest.