Complete Atrioventricular Canal Defect in a Non-syndromic Adult Patient: An Unusual Presentation

This case report presents a 30-year-old male patient with a history of autism spectrum disorder who experienced a drastic decline in physical activity in recent years. Upon examination, the patient was found to be relatively bedridden, lethargic, and unable to maintain an upright gait, accompanied by severe clubbing. Transthoracic echocardiography revealed a massive 4 cm complete atrioventricular canal (CAVC) defect. Although the patient was asymptomatic throughout most of his life, the CAVC defect appeared to have progressively impacted his health and activity tolerance. The importance of a multidisciplinary approach in early detection and timely intervention in managing CAVC defect is emphasized in this case.

Surgical Atrial Septal Patch Endocarditis in a Patient with a Complete Corrected Atrioventricular Canal Defect: A Case Report and Review of the Literature

Infective endocarditis (IE) is common in patients with corrected congenital heart disease (CHD) with a residual lesion, but is rarely found on surgical patches used to close atrial septal defects (ASDs). This is also reflected in the current guidelines that do not recommend antibiotic therapy for patients with a repaired ASD with no residual shunt six months after closure (percutaneous or surgical). However, the situation could be different in the case of mitral valve endocarditis, which causes leaflet disruption with severe mitral insufficiency and could seed the surgical patch. We present herein a 40-year-old male patient with a past medical history of a complete surgically corrected atrioventricular canal defect performed in childhood who presented with fever, dyspnea and severe abdominal pain. Transthoracic and transesophageal echocardiography (TTE and TEE) revealed vegetation at the level of the mitral valve and the interatrial septum. The CT scan confirmed ASD patch endocarditis and multiple septic emboli, guiding the therapeutic management. An accurate evaluation of cardiac structures should be mandatory when a systemic infection is detected in CHD patients, even if the defects were surgically corrected, because the detection and eradication of such infectious foci as well as a surgical reintervention are particularly difficult to achieve in this subpopulation.

Post-operative course of pulmonary artery pressure after complete atrioventricular canal defect repair

Complete atrioventricular canal defect is a CHD associated with intra-cardiac shunting of blood, which can lead to irreversible changes in pulmonary vascular resistance and pulmonary artery hypertension if unrepaired. Patients with Trisomy 21 are at risk for early development of pulmonary artery hypertension if left uncorrected.1,2.

OBJECTIVES

The purpose of this study is to describe the evolution of pulmonary artery hypertension after repair of complete atrioventricular canal defect and to determine the time to normalisation of pulmonary artery pressure in both patients with and without Trisomy 21.

METHODS

This is a single centre, retrospective analysis of patients with complete atrioventricular canal defect admitted for surgical repair at the University of Maryland Medical Center from 2005 to 2015. T-test or Mann-Whitney test and Chi-Square or Fisher's exact tests were used to compare the two groups (patients with Trisomy 21 and those without). Repeated measures of analysis of variance and serial measurement analysis were performed.

RESULTS

Twenty-nine patients meeting the inclusion criteria underwent repair of complete atrioventricular defects during the study period. The right ventricular pressure estimate remained elevated over time and did not show a significant difference between the two groups. Right ventricular to systolic blood pressure ratios for all patients remained > 0.5 over the time periods assessed.

CONCLUSIONS

Our study suggests that in patients with complete atrioventricular canal defects, the right ventricular pressure remains elevated and does not normalise on echocardiograms performed up to one year after surgery, suggesting a sustained elevation in pulmonary vascular resistance.

Common atrium/atrioventricular canal defect and postaxial polydactyly: A mild clinical subtype of Ellis-van Creveld syndrome caused by hypomorphic mutations in the EVC gene

Clinical expression of Ellis-van Creveld syndrome (EvC) is variable and mild phenotypes have been described, including patients with mostly cardiac and limb involvement. Whether these cases are part of the EvC phenotypic spectrum or separate conditions is disputed. Herein, we describe a family with vertical transmission of atrioventricular canal defect (AVCD), common atrium, and postaxial polydactyly. Targeted sequencing of EVC, EVC2, WDR35, DYNC2LI1, and DYNC2H1 identified different compound heterozygosity in EVC genotypes in the two affected members, consisting of a nonsense (p.Arg622Ter) and a missense (p.Arg663Pro) variant in the father, and the same nonsense variant and a noncanonical splice-site in-frame change (c.1316-7A>G) in the daughter. Complementary DNA sequencing, immunoblot, and immunofluorescence experiments using patient-derived fibroblasts and Evc^-/- mouse embryonic fibroblasts showed that p.Arg622Ter is a loss-of-function mutation, whereas p.Arg663Pro and the splice-site change c.1316-7A>G are hypomorphic variants resulting in proteins that retain, in part, the ability to complex with EVC2. Our molecular and functional data demonstrate that at least in some cases the condition characterized as "common atrium/AVCD with postaxial polydactyly" is a mild form of EvC due to hypomorphic EVC mutations, further supporting the occurrence of genotype-phenotype correlations in this syndrome.

Atretic right superior vena cava with left superior vena cava draining directly into left atrium with absent coronary sinus in an adult with partial atrioventricular canal defect and complete heart block

The association of atretic right superior vena cava with persistent left superior vena cava draining directly into left atrium with absent coronary sinus in atrioventricular canal defect is virtually unknown in adults with no case reported so far. Though atretic right superior vena cava with persistent left superior vena cava is an extremely rare venous anomaly seen in congenital heart disease, it has important clinical implications in cardiac surgery and interventional cardiology. Atrial arrhythmias and right bundle branch block are common with advancing age in partial atrioventricualr canal defect but complete heart block has scarcely been reported in the medical literature.

Some Isolated Cardiac Malformations Can Be Related to Laterality Defects

Human beings are characterized by a left–right asymmetric arrangement of their internal organs, and the heart is the first organ to break symmetry in the developing embryo. Aberrations in normal left–right axis determination during embryogenesis lead to a wide spectrum of abnormal internal laterality phenotypes, including situs inversus and heterotaxy. In more than 90% of instances, the latter condition is accompanied by complex and severe cardiovascular malformations. Atrioventricular canal defect and transposition of the great arteries—which are particularly frequent in the setting of heterotaxy—are commonly found in situs solitus with or without genetic syndromes. Here, we review current data on morphogenesis of the heart in human beings and animal models, familial recurrence, and upstream genetic pathways of left–right determination in order to highlight how some isolated congenital heart diseases, very common in heterotaxy, even in the setting of situs solitus, may actually be considered in the pathogenetic field of laterality defects.

Combination of left ventricular noncompaction and partial atrioventricular canal defect in a 21-year-old male: a case report

Introduction

Left ventricular noncompaction (LVNC) is classified as a genetic cardiomyopathy characterized by a progressive systolic dysfunction. It may occur alone or in association with congenital cardiac anomalies. The combination of left ventricular noncompaction with partial atrioventricular canal defect is rare and has not, to our knowledge, been described previously.

Case presentation

A 21-year-old male who traveled to our center from a neighboring country presented with signs of heart failure. Transthorarcic echocardiography showed prominent trabeculations in the left ventricle predominantly in the left ventricle involving the apical lateral and mid anterolateral segments associated with a partial atrioventricular canal defect. There was a biventricular systolic dysfunction. There was good response to medical treatment.

Conclusion

This case stresses the importance of maintaining a high degree of suspicion for this rare cardiomyopathy and the need to systematically look for other associated anomalies in order to institute proper short- and long-term managements.

Complete atrioventricular canal defect: surgical considerations

Complete atrioventricular canal defect is a serious and complex cardiac anomaly that is frequently associated with other congenital cardiac defects. Its natural course is ultimately fatal; 80% of children born with this defect will die within 2 years. Long-term medical therapy for complete atrioventricular canal defect is ineffective; therefore, either palliative or curative surgery is required. The risk of corrective surgery for this defect in infancy has steadily decreased because of improvements in surgical techniques, anesthesia, and postoperative management. This report describes our current surgical technique for primary corrective repair of complete atrioventricular canal defect, with a review of recent results of this procedure in 34 patients.