Dextrocardia in Adults with Congenital Heart Disease

Spectrum of Heart Diseases in Children in a National Cardiac Referral Center Tanzania, Eastern Africa: A Six-Year Overview

Background

While communicable diseases have long been the primary focus of healthcare in Africa, the rising impact of paediatric and congenital heart disease (CHD) cannot be overlooked. This research aimed to estimate the frequency and pattern of heart diseases in children who underwent their first echocardiography at a national cardiac referral hospital in Tanzania.

Methods

A retrospective observational study was conducted on children aged 0 to 18 years referred for first-time cardiological evaluation from January 2017 to December 2022. Retrieval of social and echocardiogram data and descriptive analysis were performed.

Results

There were 6,058 children with complete reports. Of these, 52.8% (3,198) had heart disease, of whom 2,559 (80%) had CHD, while (340/639; 53.2%) with acquired heart disease (AHD) had rheumatic heart disease (RHD). Children with CHD had a median age 1.0 years (IQR: 0.3-3.5) and were predominantly 51.2% male. Children with RHD had a median age 9.7 years (IQR: 3.2-13.8) with equal gender distribution. Shunt lesions were common in 1,487 (58.1%), mainly VSD 19.3%, PDA 19.1%, ASD 15.1%, and atrioventricular septal defect (AVSD) 4.6%. Pulmonary valve stenosis was in 97 (3.8%). Around 35% (718) had cyanotic CHD, with TOF being most common (13.3%), followed by double outlet right ventricle (DORV) (3.6%). Compared to global average truncus arteriosus was higher in 69 (2.3%) children. In contrast, TGA and hypoplastic left heart syndrome (HLHS) were lower than the estimated global average seen in 2.3% and 0.5% of the cases, respectively. Atresia of the right-side valves was more common (174 vs. 24), and approximately 40% of the patients referred for first-time echocardiographic evaluation required hospitalization.

Conclusion

Congenital heart disease is the primary cause of heart disease in children presenting at a national referral hospital, surpassing RHD. With its distinct distribution pattern, acyanotic lesions are more frequent than cyanotic heart diseases. The observed late referral tendencies suggest improving the referral system, enhancing CHD awareness among healthcare professionals, and instituting nationwide screening programs.

Role of autopsy in diagnosing asplenia and right bilobed lung in a fetus with dextrocardia

We present a unique case of a fetus with dextrocardia, asplenia and a right bilobed lung in a primigravida woman in her 20s at 21 weeks' gestation. Prenatal ultrasound examination revealed dextrocardia and other anomalies such as atrioventricular septal defect and situs ambiguous with the gallbladder on the left, leading to termination of the pregnancy. Fetal autopsy confirmed the diagnosis, detected additional findings such as asplenia and right bilobed lung missed on ultrasound and highlighted the importance of autopsy in prenatal diagnosis. This rare case emphasises the value of a comprehensive prenatal assessment, fetal autopsy and a multidisciplinary approach in diagnosing, managing and counselling families affected by congenital anomalies. Timely detection and appropriate genetic counselling can guide affected families in making informed decisions regarding future pregnancies while providing closure and support in their grieving process.

Identification of novel compound heterozygous variants in the DNAH1 gene of a Chinese family with left-right asymmetry disorder

Most internal organs in humans and other vertebrates exhibit striking left-right asymmetry in position and structure. Variation of normal organ positioning results in left-right asymmetry disorders and presents as internal organ reversal or randomization. Up to date, at least 82 genes have been identified as the causative genetic factors of left-right asymmetry disorders. This study sought to discover potential pathogenic variants responsible for left-right asymmetry disorder present in a Han-Chinese family using whole exome sequencing combined with Sanger sequencing. Novel compound heterozygous variants, c.5690A>G (p.Asn1897Ser) and c.7759G>A (p.Val2587Met), in the dynein axonemal heavy chain 1 gene (DNAH1), were found in the proband and absent in unaffected family members. Conservation analysis has shown that the variants affect evolutionarily conserved residues, which may impact the tertiary structure of the DNAH1 protein. The novel compound heterozygous variants may potentially bear responsibility for left-right asymmetry disorder, which results from a perturbation of left-right axis coordination at the earliest embryonic development stages. This study broadens the variant spectrum of left-right asymmetry disorders and may be helpful for genetic counseling and healthcare management for the diagnosed individual, and promotes a greater understanding of the pathophysiology.

Successful radiofrequency catheter ablation of Wolff-Parkinson-White syndrome in a patient with dextrocardia: A case report

Background

Dextrocardia is a congenital heart malformation with a low incidence that occurs in only 1 in 10,000–12,000 people. Wolff-Parkinson-White (WPW) syndrome is a congenital condition with additional accessory pathways between the atria and the ventricle, which affects up to three in 1,000 people worldwide. Experience of radiofrequency catheter ablation in patients with WPW syndrome and dextrocardia is scarce due to its rare incidence.

Case presentation

A 39-year-old female was hospitalized due to two episodes of palpitations in the latest 2 months. The morphology of the P-QRS-T complex of lead aVR and aVL, II, and III were presented invertedly as common conditions, and shortened P-R interval and a characteristic “delta” wave were shown on the electrocardiogram (EGM). The patient with dextrocardia and situs invertus malposition was confirmed by chest-X ray, cardiac color Doppler echocardiography. The patient was diagnosed with WPW syndrome with dextrocardia and underwent radiofrequency catheter ablation (RFCA) successfully. In this case, the key to the success of RFCA is to understand the anatomical structure of the heart and the great vessels before the operation and make a personalized operative plan.

Conclusion

Catheter ablation for tachycardia patients with dextrocardia is efficient and safe. For patients with dextrocardia, the key to successful ablation was adjusting for projection angulation and different catheter manipulation compared with a standard case because of the mirror image of a normal heart.

Analysis of outcomes in patients with abnormal laterality undergoing congenital heart surgery

OBJECTIVE

Laterality anomalies are almost always associated with severe cardiac anomalies. Demographic properties, type of the procedures, associated anomalies, and early and mid-term prognosis of four types of laterality anomalies were analysed.

METHODS

A total of 64 consecutive patients with laterality anomalies were enrolled between July 2014 and July 2020. We grouped the patients as situs solitus dextrocardia (SSD) (n = 12; 18.7%); situs inversus (SI) (n = 16; 25%); right atrial isomerism (RAI) (n = 29; 45.3%); and left atrial isomerism (LAI) (n = 7; 10.9%). TAPVC was only present in the RAI group (31%). Incidence of mitral or tricuspid atresia was higher in the SSD group (25%). All the patients were followed up with a mean of 19.06 ± 17.6 (0.1-72) months.

RESULTS

Early postoperative mortality was 17 patients, among 107 procedures (15.8%). Twelve patients were in the neonatal period. All ten patients survived after isolated ductal stenting. Fourteen of the deaths were in the RAI group (48.3%). The 3-year survival rates were 85% in LAI, 78.7% in SI, 55.8% in SSD, and 38% in RAI groups. According to the multivariable Cox regression model, mechanical ventilation, kidney injury, RAI, and complex surgery in the neonatal period were independent risk factors for early mortality.

CONCLUSION

Laterality anomalies are one of the most challenging patients who commonly had univentricular physiology. The most prevalent anomaly was RAI, and RAI had the worst outcome and survival. Ductal stent is an acceptable first intervention during the neonatal period in suitable patients. Complex procedures may carry a high risk of death in the neonatal period.

Sinus venosus atrial septal defect and partial anomalous pulmonary venous connection in a patient with dextrocardia

An 85-year-old woman presenting with symptomatic pulmonary hypertension (PH) with a history of dextrocardia was referred to our facility for treatment of heart failure. Significant shunting was detected by measuring oxygen saturation during right heart catheterisation (RHC). CT with contrast revealed sinus venosus atrial septal defect (SVASD) and partial anomalous pulmonary venous connection (PAPVC), in which the left upper and middle lobar pulmonary veins returned to the superior vena cava and right atrium. Despite medical treatment, the patient died, and an autopsy was performed. SVASD and PAPVC are rare congenital anomalies. RHC with measurement of oxygen saturation and CT with contrast should be considered in patients with unexplained right atrial and ventricular enlargement or suspected PH.

Pulmonary Vein Isolation and Pacemaker Implantation in a Patient with Dextrocardia Situs Inversus

A 70-year-old female with dextrocardia with situs inversus (DSI) totalis and inferior vena cava occlusion underwent radiofrequency catheter ablation because she had symptomatic paroxysmal atrial fibrillation (AF). Careful preoperative examination made successful pulmonary vein isolation through the left jugular vein approach. One-year later, however, AF recurred, and symptomatic sinus bradycardia or junctional bradycardia often occurred. Then, the pacemaker was implanted. We here reported a rare case of congenital abnormality, DSI with inferior vena cava occlusion who had undergone successful pulmonary vein isolation and pacemaker implantation without any complications.

A Novel Nonsense MMP21 Variant Causes Dextrocardia and Congenital Heart Disease in a Han Chinese Patient

The position and morphology of human internal organs are asymmetrically distributed along the left-right axis. Aberrant left-right patterning in the developing embryo can lead to a series of congenital laterality defects, such as dextrocardia and heterotaxy syndrome. Laterality defects are a genetic condition; however, pathogenic genetic lesions are found in only one-fifth of patients. In this study, whole-exome sequencing was conducted for 78 patients with laterality defects. We identified a novel stopgain variant in MMP21 (c.G496T; p.G166^*) in a Chinese patient with mirror-image dextrocardia. This variant caused a truncated MMP21 mRNA containing only the signal peptide and propeptide, while the coding sequence of matrix metalloproteinase-21 was almost entirely absent. To the best of our knowledge, this novel variant is the first homozygous stopgain variant identified in dextrocardia patients, and the first MMP21 variant found in East Asia. Our findings expand the spectrum of MMP21 variants and provide support for the critical role of MMP21 during left-right patterning in the Han Chinese population.

Radiofrequency catheter ablation in a patient with dextrocardia, persistent left superior vena cava, and atrioventricular nodal reentrant tachycardia: A case report

RATIONALE

Dextrocardia is a rare congenital heart disease, while the persistent left superior vena cava (PLSVC) is an uncommon congenital vascular malformation. It is extremely rare for a person to have dextrocardia and PLSVC. A case with a combination of dextrocardia, PLSVC, and atrioventricular nodal reentrant tachycardia has not been reported.

PATIENT CONCERNS

A 51-year-old woman was admitted to the hospital with palpitations. The physical examination revealed a heart rate of patient increased significantly, and that apex beating was found in the right fifth intercostal space approximately 0.5 cm from the midclavicular line.

DIAGNOSIS

We used different techniques, including electrocardiography, esophagus heart electrophysiology, chest radiograph, and cardiac color Doppler echocardiography to reveal the presence of the combination of dextrocardia, PLSVC, and supraventricular tachycardia.

INTERVENTIONS

We terminated tachycardia by esophageal pacing and cured patients with radiofrequency catheter ablation (RFCA).

OUTCOMES

The complex structural anomalies presented great technical challenges for interventional treatments. After consulting the literature, thorough examination and understanding of the structural anatomy and anomalies of the vena cava and cardiac chambers, we successfully treated this patient by RFCA. After half a year of follow-up, the patient did not have palpitations, and no arrhythmia was seen on the electrocardiography.

LESSONS

Physicians need to be aware that the key to the success of RFCA, in this case, is to clarify the complexity of the morphological and anatomical structures of dextrocardia accompanying PLSVC and to consult and understand the experience of access vessels reported in relevant cases before the operation.

Stress cardiomyopathy in dextrocardia with situs inversus and anomalous coronary arteries

We present a 53-year-old male with the rare constellation of stress cardiomyopathy, dextrocardia with situs inversus and anomalous coronary anatomy. This case highlights the difficulties faced when managing patients with uncommon disorders and demonstrates a rare overlap of acquired and CHD.

Effective alcohol septal ablation for left ventricular outflow tract obstruction in a patient with isolated dextrocardia

Isolated dextrocardia is a congenital anomaly characterised by the normal position of the thoracic and abdominal viscera with a right cardiac apex. Left ventricular outflow tract obstruction (LVOTO) is a common structural manifestation of hypertrophic cardiomyopathy (HCM). A 65-year-old woman had worsening chest discomfort and dyspnoea on exertion. Chest CT angiography identified the isolated dextrocardia and HCM. Colour Doppler echocardiography showed mosaic flow in the LV outflow, indicating LVOTO. We performed alcohol septal ablation (ASA) under intracardiac echocardiography (ICE)-guided selective myocardial contrasting. This procedure improved provoked intra-LV pressure gradient by Valsalva manoeuvre and nitroglycerin injection from 136 to 50 mm Hg and her symptoms. The unique combination of isolated dextrocardia and left ventricular hypertrophy could have been involved in the formation of latent LVOTO. Even with the anomaly, contrast ICE made it possible to clarify the target septal left ventricular wall of ASA, and we could perform ASA safely.

Implantation of VVI pacemaker in a patient with dextrocardia, persistent left superior vena cava, and sick sinus syndrome: A case report

BACKGROUND

Dextrocardia, or right-lying heart, is an uncommon congenital heart disease in which the apex of the heart is located on the right side of chest. Persistent left superior vena cava (PLSVA) is a rare venous anomaly that is often associated with the abnormalities of cardiac transduction system. A case with combination of dextrocardia, persistent left superior vena cava, and sick sinus syndrome has not been reported.

METHODS

We used different techniques including cardiac color Doppler echocardiography, 24-hour Holter monitoring, and abdominal ultrasound to make a diagnosis and treated the patient by implanting a VVI pacemaker.

RESULTS

A 50-year-old woman was admitted with a syncope. Angiography of the right atrium and superior vena cava, echocardiography, electrocardiography, and abdominal ultrasound revealed the presence of the combination of mirror image dextrocardia, PLSVA, and sick sinus syndrome. The complex structural anomalies presented great technical challenges for interventional treatments. After thorough examination and understanding of the structural anatomy and anomalies of the superior and inferior vena cava and cardiac chambers, we successfully treated this patient by implanting a VVI pacemaker.

CONCLUSION

Physicians must be aware of the complexity of the morphological and anatomical structures of dextrocardia accompanying PLSVC. Given that the diagnosis of situs inversus was performed at a relatively advanced age, it is therefore important to make such a correct diagnosis followed by appropriate therapeutic intervention.