Isolated right ventricular hypoplasia

Isolated right ventricular hypoplasia associated with cyanotic atrial septal defect: a case report

Background

Hypoxaemia in isolated right ventricular (RV) hypoplasia (IRVH) is primarily caused by a right-to-left shunt (RLS) at the atrial level, such as an atrial septal defect (ASD). When considering closure of the RLS, it should be closed only after ensuring that it will not cause right-sided heart failure (HF).

Case summary

A 21-year-old woman had been experiencing shortness of breath during exertion since childhood. Transthoracic and transoesophageal echocardiography revealed an ASD with bidirectional shunting, and microbubble test revealed a marked RLS. Cardiac magnetic resonance imaging revealed a hypoplastic RV end-diastolic volume corrected for body surface area of 47 mL/m2 (70% of normal range). Right heart catheterization revealed a decreased Qp/Qs ratio of 0.89 and a pressure waveform with a clear increase in the 'A'-wave, although the mean right atrial pressure was not high (4 mmHg). Therefore, the patient was diagnosed with cyanotic ASD and IRVH. A temporary balloon occlusion test was performed to evaluate the right-sided heart response to capacitive loading prior to ASD closure. After treatment, the patient's improved markedly. The pre-operative brain natriuretic peptide (BNP) level was normal; however, 6 months after ASD closure, the BNP level was elevated, and the continuous-wave Doppler waveform of pulmonary regurgitation at the time of transthoracic echocardiography changed, suggesting an increase in diastolic RV pressure.

Discussion

When ASD is complicated by hypoxaemia, the possibility of IRVH, although rare, should be considered. Another difficult point is determining whether the ASD can be closed, considering its immature RV compliance.

Isolated left ventricular apical hypoplasia: Systematic review and analysis of the 37 cases reported so far

BACKGROUND

Isolated left ventricular apical hypoplasia (ILVAH), also known as truncated left ventricle (LV), is a very unusual cardiomyopathy. It is characterised by a truncated, spherical, and non-apex forming LV. The true apex is occupied by the right ventricle. Due to the rarity of the disease, just a few case reports and limited case series have been published in the field.

AIM

To analysing the so far 37 reported ILVAH cases worldwide.

METHODS

The electronic databases PubMed and Scopus were investigated from their establishment up to December 13, 2022.

RESULTS

The majority of cases reported occurred in males (52.7%). Mean age at diagnosis was 26.1 ± 19.6 years. More than a third of the patients were asymptomatic (35.1%). The most usual clinical presentation was breathlessness (40.5%). The most commonly detected electrocardiogram changes were T wave abnormalities (29.7%) and right axis deviation with poor R wave progression (24.3%). Atrial fibrillation/flutter was detected in 24.3%. Echocardiography was performed in 97.3% of cases and cardiac MRI in 91.9% of cases. Ejection fraction was reduced in more than a half of patients (56.7%). An associated congenital heart disease was found in 16.2%. Heart failure therapy was administered in 35.1% of patients. The outcome was favorable in the vast majority of patients, with just one death.

CONCLUSION

ILVAH is a multifaceted entity with a so far unpredictable course, ranging from benign until the elderly to sudden death during adolescence.

Clinical Status and Outcome of Isolated Right Ventricular Hypoplasia: A Systematic Review and Pooled Analysis of Case Reports

Background

Isolated right ventricular hypoplasia (IRVH), not associated with severe pulmonary or tricuspid valve malformation, is a rare congenital myocardial disease. This study aims to evaluate the clinical status and outcome of IRVH.

Methods

A systematic search of keywords on IRVH was conducted. Studies were searched from MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi (Ichushi) published between January 1950 and August 2021.

Results

Thirty studies met the inclusion criteria. All of these studies were case reports and included 54 patients (25 males and 29 females). The median age of the patients was 2.5 years old (0-15.3 years). Of the 54 patients, 13 (24.1%) reported a family history of cardiomyopathy. Moreover, 50 (92.6%), 19 (35.2%), and 17 (31.5%) patients were diagnosed with cyanosis, finger clubbing, and dyspnea, respectively. Furthermore, 53 (98.2%) patients had a patent foramen ovale or an atrial septal defect (ASD). Z-score of the tricuspid valve diameter on echocardiogram was -2.16 ± 1.53, concomitant with small right ventricular end-diastolic volume. In addition, 29 (53.7%), 21 (38.9%), 7 (13.0%), and 2 (3.7%) patients underwent surgery, ASD closure, Glenn operation, and one and a half ventricular repair, respectively. Among them, nine (20.4%) patients expired, and the multivariable logistic regression analysis showed that infancy, heart failure, and higher right ventricular end-diastolic pressure were risk factors for death.

Conclusions

IRVH was diagnosed early in children with cyanosis and was associated with high mortality. This systematic review and pooled analysis provided evidence to assess the of IRVH degree in order to evaluate the clinical status and outcome of IRVH.

Blood Flow Disturbance and Morphological Alterations Following the Right Atrial Ligation in the Chick Embryo

Collectively known as congenital heart defects (CHDs), cardiac abnormalities at birth are the most common forms of neonatal defects. Being principally responsible for the heart‘s pumping power, ventricles are particularly affected by developmental abnormalities, such as flow disturbances or genomic defects. Hypoplastic Right Heart Syndrome (HRHS) is a rare disease where the right ventricle is underdeveloped. In this study, we introduce a surgical procedure performed on chick embryo, termed right atrial ligation (RAL) for disturbing hemodynamics within the right heart aiming in order to generate an animal model of HRHS. RAL is a new surgical manipulation, similar to the well-studied left atrial ligation (LAL) surgery but it induces the hemodynamic change into the right side of the heart. After inducing RAL, We utilized techniques such as Doppler ultrasound, x-ray micro-CT, histology, and computational fluid dynamics (CFD) analysis, for a comprehensive functional and structural analysis of a developing heart. Our results displayed that RAL does not induce severe flow disturbance and ventricular abnormalities consistent with clinical findings. This study allows us to better understand the hemodynamics-driven CHD development and sensitivities of ventricles under disturbed flows.

Isolated ventricular apical hypoplasia: A report of four cases and literature review

Isolated ventricular apical hypoplasia (IVAH) is a rare congenital cardiac anomaly, with clinical manifestations depending on the age of the patient, ranging from no symptoms in children to congestive heart failure or even malignant tachycardia in adults. Herein, we describe the clinical and anatomical findings in four cases with hypoplasia of the right or left ventricular apex, and we discuss the possible mechanisms and differential diagnosis of this malformation. Echocardiography is a rapidly accessible, low cost, noninvasive technique for the detection and evaluation of IVAH.

Best management in isolated right ventricular hypoplasia with septal defects in adults

Hypoplastic right ventricle is a rare congenital disease usually associated with pulmonary atresia or tricuspid atresia. Isolated right ventricular hypoplasia is a rare anomaly without important valvular abnormalities. It is associated with inter atrial septal defects leading to the right-to-left shunting of blood. Patients with isolated right ventricular hypoplasia usually have different and variable courses. In some patients, it is recognized in the perinatal period and necessitates prompt intervention; nonetheless, there are some reports of this anomaly in old age with no significant symptoms. In this report, we describe the clinical data and management of 6 adult cases with isolated right ventricular hypoplasia treated medically or surgically based on the severity of the disease and symptoms and then offer an in-depth discussion regarding this rare anomaly.

A successful heart and liver transplantation requiring intraoperative extracorporeal membrane oxygenation for primary cardiac allograft dysfunction in a patient with Fontan failure

We report a case of successful heart and liver transplantation requiring intraoperative extracorporeal membrane oxygenation (ECMO) for primary cardiac allograft dysfunction in a patient with Fontan failure. A successful outcome for both the heart and the liver can be achieved with the timely management of ECMO support. In describing our experiences treating a Fontan patient requiring multiorgan transplantation, we have shown that challenging cases such as this one can have successful outcomes if multidisciplinary collaborations and proper treatment strategies are utilized at the optimal timing, along with family support and patient cooperation.

Asymptomatic Right Ventricular Hypoplasia in Twin Siblings: A Normal Variant or Cause of Early Mortality?

Right ventricular (RV) hypoplasia may develop secondary to pulmonary or tricuspid valve atresia. These patients are usually symptomatic early in life and need prompt intervention. Isolated RV hypoplasia is a rare congenital heart disease. We report a case of 23-year-old twins who have been monitored for the last 14 years for isolated right ventricular hypoplasia. ECHO and MRI studies showed a small, heavily trabeculated, nonapex-forming RV and mild tricuspid valve insufficiency. The girl has a patent foramen ovale (PFO). Otherwise, the cardiac anatomy and function was normal. They have both been completely asymptomatic from the cardiac standpoint. The family history is remarkable for death of father at the age of 30 years with autopsy suggestive of a hypoplastic RV. The paternal uncle also died at the age of 46 years, and his son has an unidentified congenital heart disease. The family history appears to suggest an autosomal dominant pattern of inheritance with variable expressivity. However, the chromosome microarray analysis of the twins did not identify any variations of clinical significance.

Cerebral and cardiac congenital malformations in neonatal West Indian manatees (Trichechus manatus)

Strandings of live new-born West Indian manatees (WIMs; Trichechus manatus) are one of the main challenges for the conservation of this species in Brazil, particularly in the northeastern states. Congenital malformations (CMs) are rare in sirenians. We identified CMs in two of 19 stranded WIMs that were rescued, rehabilitated and subjected to complete pathological examinations in Ceará and Rio Grande do Norte States between 1992 and 2017. In case 1, dilation of the cerebral lateral and fourth ventricles with abundant cerebrospinal fluid (internal hydrocephalus), was diagnosed. Furthermore, this animal developed necrotizing enterocolitis associated with pneumatosis intestinalis and aspiration pneumonia late during rehabilitation. Cardiac malformations in case 2 included: right ventricle hypoplasia with marked stenosis of the tricuspid outflow, high ventricular septal defect, segmental pulmonary artery aneurysm, mitral valve haemocyst and left ventricular hypertrophy. Herein, we provide the first description of a neural tube defect, specifically a developmental internal hydrocephalus, and multiple cardiac congenital anomalies, together with their respective clinicopathological features in manatees. Although the aetiology of the CMs remains unknown in these cases, a genetic basis is plausible given the low genetic variability in this population. These cases add to the body of knowledge on health and disease aspects of manatees and may provide scientific basis for future medical and conservation efforts on neonatal WIMs.

Precardiac organoids form two heart fields via Bmp/Wnt signaling

The discovery of the first heart field (FHF) and the second heart field (SHF) led us to understand how cardiac lineages and structures arise during development. However, it remains unknown how they are specified. Here, we generate precardiac spheroids with pluripotent stem cells (PSCs) harboring GFP/RFP reporters under the control of FHF/SHF markers, respectively. GFP⁺ cells and RFP⁺ cells appear from two distinct areas and develop in a complementary fashion. Transcriptome analysis shows a high degree of similarities with embryonic FHF/SHF cells. Bmp and Wnt are among the most differentially regulated pathways, and gain- and loss-of-function studies reveal that Bmp specifies GFP⁺ cells and RFP⁺ cells via the Bmp/Smad pathway and Wnt signaling, respectively. FHF/SHF cells can be isolated without reporters by the surface protein Cxcr4. This study provides novel insights into understanding the specification of two cardiac origins, which can be leveraged for PSC-based modeling of heart field/chamber-specific disease.

The heart arises from distinct progenitor cells of both the first and second heart fields (FHF and SHF). Here, the authors generated precardiac organoids from mouse and human pluripotent cells and show that FHF and SHF cells form similarly to their in vivo counterparts in response to BMP and Wnt signalling, respectively.

Isolated right ventricular apical hypoplasia characterized by computed tomography and echocardiography

Isolated right ventricular apical hypoplasia is an unusual congenital heart disease that has been mentioned in only one report to our knowledge. We describe the case of a 62-year-old male patient suffering from recurrent abdominal distention, nausea, and lower extremity edema. The right ventricular morphologic abnormalities as shown by echocardiography and CT were comparable to those of left ventricular apical hypoplasia, suggesting right ventricular apical hypoplasia. However, this speculative diagnosis remains to be confirmed by additional cases. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:82-84, 2018.

Hypoplastic right heart syndrome, absent pulmonary valve, and non-compacted left ventricle in an adult

Hypoplastic right heart syndrome is a rare cyanotic congenital heart disease with under-development of the right ventricle, tricuspid, and pulmonary valves leading to right-to-left shunting of the blood through inter-atrial septal defect. Perinatal mortality is high with very few patients surviving to adulthood without corrective surgery. This report describes a 26-year-old young woman, who had recurrent abortions and stillbirths and detected to have marked cyanosis with hypoplastic right heart, sub-arterial ventricular septal defect, absent pulmonary valve, non-compaction of the left ventricle, and bicuspid aortic valve with aortic regurgitation. The patient died owing to progressive heart failure 4 years after the diagnosis was made.

Cone Reconstruction of Atypical Ebstein Anomaly Associated with Right Ventricular Apical Hypoplasia

Cone reconstruction for tricuspid valve repair has revolutionized the surgical treatment of Ebstein anomaly. We present the case of a 58-year-old woman with atypical Ebstein anomaly and right ventricular apical hypoplasia who was spared from palliative shunt physiology by our use of cone reconstruction. Compared with other techniques, cone reconstruction of the tricuspid valve more closely replicates normal valvular anatomy and function. This surgical procedure can be applied to many anatomic variations of Ebstein anomaly, as in our patient's apparently unique instance of atypical Ebstein anomaly with right ventricular apical hypoplasia.

Isolated left ventricular apical hypoplasia: a new congenital anomaly described with cardiac tomography

OBJECTIVE

To describe cardiac tomography findings of an apparently new, presumably congenital, left ventricular (LV) abnormality noted consistently in three patients.

PATIENTS

Three patients presenting with non-specific symptoms including fatigue, shortness of breath, or chest discomfort were evaluated with cardiac tomography for cardiac structure and function.

RESULTS

Findings from the three patients were very similar: a truncated and spherical LV with abnormal diastolic and systolic function, invagination of fatty material into the myocardium of the defective LV apex, origin of a complex papillary network in the anteroapical LV, and an elongated right ventricle wrapping around the deficient apex.

CONCLUSIONS

Isolated LV apical hypoplasia is a unique, presumably congenital, cardiac anomaly that is an important condition to recognise.

Pulmonary Atresia with Intact Ventricular Septum

The prognosis for patients with pulmonary atresia with intact ventricular septum is poor with and without conventional surgical treatment. Because of this reason, a comprehensive program of medical, transcatheter, and surgical treatment is necessary to improve the long-term outlook of these infants. Algorithms of management plans should be developed based on the presence of right ventricular-dependent coronary circulation as well as size and morphology of the right ventricle. In a tripartite or bipartite right ventricle, transcatheter radiofrequency perforation is preferable. Alternatively, surgical valvotomy may be performed. Augmentation of pulmonary blood flow by prolonged infusion of prostaglandin E(1), stenting the ductus, or a surgical modified Blalock-Taussig shunt may be necessary in some of these patients. In patients with a unipartite or very small right ventricle or a right ventricular-dependent coronary circulation (Tricuspid valve Z score < -2.5), augmentation of pulmonary flow along with atrial septostomy should be undertaken. Follow-up studies to determine the feasibility of biventricular repair should be undertaken and, if feasible, surgical or transcatheter methods may be used to achieve the goals. If not suitable for biventricular repair, one-ventricle (Fontan) or one and one-half ventricular repair should be considered. Comprehensive and well-planned treatment algorithms may help improve survival rate.

Biventricular hearts not amenable to biventricular repair

Many hearts, although considered morphologically biventricular, may not be candidates for a biventricular repair. Such patients are best placed on a Fontan algorithm. This article reviews in broad principles those hearts that, despite being biventricular, do not lend themselves to a two-ventricle repair.

Isolated right ventricular hypoplasia: intraoperative balloon occlusion test

A 42-year-old woman with isolated right ventricular hypoplasia underwent operation. To determine the optimal procedure, we temporarily occluded the atrial septal defect with a balloon catheter that was introduced through the right atrial appendage. The hemodynamics were stable throughout the occlusion test. Simple closure of the atrial septal defect was safely accomplished. Intraoperative occlusion test with the balloon catheter was a good alternative to preoperative occlusion test.

Comprehensive management of pulmonary atresia with intact ventricular septum

The prognosis for patients with pulmonary atresia with intact ventricular septum is poor with or without conventional surgical intervention. Therefore, a comprehensive program of medical and surgical treatment is necessary to improve long-term outlook for these infants. Such a program consists of management of the neonate at initial presentation with prompt administration of prostaglandins and institution of a combination of surgical procedures (isolated pulmonary valvotomy, valvotomy plus modified Blalock-Taussig shunt, Blalock-Taussig shunt plus balloon atrial septostomy, or Blalock-Taussig shunt alone) depending on the results of morphological analysis of the right ventricle; this treatment regimen is designed to relieve hypoxemia, encourage right ventricular growth, and provide adequate egress of blood from the right atrium. Another important element of management is to perform follow-up hemodynamic and angiographic studies when the patient is between 6 and 12 months old to ensure that the objectives of the comprehensive program are being met. Finally, a definitive repair should be offered. This can be done by using or bypassing the right ventricle, depending on whether it can support the pulmonary circuit.

Extreme right ventricular hypoplasia after relief of severe pulmonary stenosis. Use of balloon catheter occlusion of atrial septal defect in assessing right ventricular function

A patient is described in whom extreme right ventricular hypoplasia and right-to-left shunting through an atrial septal defect occurred after relief of severe pulmonary stenosis. The ability of the hypoplastic right ventricle to deal with an increased volume load was assessed at cardiac catheterisation by occluding the atrial septal defect with a balloon tipped catheter.

Coxsackie virus B3 perimyocarditis in BALB/c mice: experimental model of chronic perimyocarditis in the right ventricle

Severe perimyocarditis was induced in weanling BALB/c mice inoculated with Coxsackie virus B3 (Nancy strain). Yellowish-white patches were seen only on the surface of the right ventricle of the heart on the 7th to the 180th day after the inoculation. More than half the animals were affected. Following myocardial degeneration and necrosis, mononuclear cell infiltration was evident on the 7th day. After the 28th day, perimyocardial fibrosis increased and cellular infiltration gradually decreased. Marked perimyocardial fibrosis with calcification which was limited to the right ventricle was observed 90 days after inoculation and persisted to the 180th day. This animal model enables studies on the natural history of perimyocarditis of viral aetiology and its possible sequels, chronic or constrictive pericarditis, in humans. A possible role of Coxsackie virus infection in the pathogenesis of idiopathic right ventricular myocardial hypoplasia in association with right ventricular dilatation in man (Uhl's anomaly) is discussed.

Uhl's anomaly

Uhl's anomaly of the heart is a rare condition. Another well-documented case is presented with a review of the published reports outlining the main clinical features and the bad overall prognosis. Right atriotomy should be avoided if closure of the atrial septal defect is attempted.

Echocardiographic findings in Uhl's anomaly. Demonstration of diastolic pulmonary valve opening

The echocardiographic findings in a case of Uhl's anomaly, or congenital hypoplasia of the right ventricular myocardium, are reported. Diastolic opening of the pulmonary valve is described. Comparison is made with echocardiograms in Ebstein's disease of the tricuspid valve, and it is suggested that echocardiography can help in differentiating these two entities. In addition to the pulmonary valve finding, increased right ventricular dimension, delayed tricuspid closure and abnormality (prolapse) of the mitral valve were noted. The echocardiographic findings are compared with cardiac catheterization data.

Right-to-left interatrial shunting with normal right ventricular pressure. A puzzling haemodynamic picture associated with some rare congenital malformations of the right ventricle and tricuspid valve

Haemodynamic and angiographic findings are described in 5 cases with rare anomalies of the right ventricle and the second there was isolated congenital 'absence' of the tricuspid valve. The remaining 3 cases all had isolated congenital hypoplasia of the right ventricle; in 2 of these 3 cases closure of the atrial septal defect was successful in abolishing cyanosis and symptoms,while the third is awaiting surgical correction.