Double-chambered right ventricle presenting in adulthood

Double-Chambered Right Ventricle in Adulthood: A Case Series

•DCRV is a rare cardiac anomaly leading to subvalvular RVOT obstruction. •DCRV is most frequently found in children but can occur in adults. •Adults with DCRV are often initially misdiagnosed. •Echocardiography is the first-line imaging modality to visualize this anomaly. •Providers should be aware of this condition and the associated image findings.

Early and mid-term outcomes of double-chambered right ventricle repair: An 8-year experience

BACKGROUND/AIM

Double-chambered right ventricle is a rare and progressive condition that is characterised by obstruction of the right ventricular tract. Double-chambered right ventricle is usually associated with ventricular septal defect. Early surgical intervention is recommended in patients with these defects. Based on this background, the present study aimed to review early and midterm outcomes of primary repair after double-chambered right ventricle.

METHODS

Between January 2014 and June 2021, 64 patients with a mean age of 13.42 ± 12.31 years underwent surgical repair for double-chambered right ventricle. The clinical outcomes of these patients were reviewed and assessed retrospectively.

RESULTS

An associated ventricular septal defect was present in all the recruited patients; 48 (75%) patients of sub-arterial type, 15 (23.4%) of perimembranous, and 1 (1.6%) patient of muscular type. The patients were followed up for a mean period of 46.73 ± 27.37 months. During their follow-up, a significant decrease in the mean pressure gradient from 62.33 ± 5.52 mmHg preoperatively to 15.73 ± 2.94 mmHg postoperatively was observed (p < 0.001). Notably, there were no hospital deaths.

CONCLUSIONS

The development of double-chambered right ventricle in association with ventricular septal defect results in an increased pressure gradient within the right ventricle. The defect needs correction in a timely manner. In our experience, the surgical correction of double-chambered right ventricle is safe and shows excellent early and mid-term results.

Dynamic cardiac computed tomography characteristics of double-chambered right ventricle

To introduce image characteristics of double-chambered right ventricle on cardiac computed tomography and set a diagnostic criterion for the diagnosis. We retrospectively collected and measured the right ventricular constrictive ratio on computed tomography images in children who had simple ventricular septal defects in the past 10 years, because double-chambered right ventricle is often associated with ventricular septal defects. The right ventricular constrictive ratio was defined as the subinfundibular cross-sectional intraluminal area during end-systole divided by the area during end-diastole in the same patient. We compared the right ventricular constrictive ratio between subjects with concomitant double-chambered right ventricle and those without. 52 children were included, and 23 (44.2%) of them have concomitant double-chambered right ventricle. In most cases (n = 21; 91.3%), the hypertrophied muscular bundles occur just inferior to the level of the supraventricular crest in the right ventricle. Mean right ventricular constrictive ratio in patients with double-chambered right ventricle (15%) was significantly smaller than that without (29%). A cut-off value of a right ventricular constrictive ratio less than 20.1% was established to diagnose double-chambered right ventricle with an 89.7% sensitivity and 78. 3% specificity. Right ventricular constrictive ratio can be a valuable asset for the preoperative diagnosis of double-chambered right ventricle with cardiac computed tomography.

Case report: Double-chambered right ventricle diagnosed in a middle-aged female with hypertrophic cardiomyopathy and atrial flutter: A rare case

Double-chambered right ventricle (DCRV) is a rare congenital heart defect in adults, manifesting with progressive right ventricular outflow tract obstruction. We describe the first case of DCRV coexisting with hypertrophic cardiomyopathy, which is complicated by atrial flutter. A middle-aged woman with recurrent symptomatic atrial flutter who had previously been diagnosed with biventricular hypertrophic cardiomyopathy was admitted to our department. Echocardiography and cardiac magnetic resonance revealed asymmetrical interventricular septal hypertrophy, and abnormal muscle bundles within the right ventricle, generating an obstructive gradient. Genetic testing detected a hypertrophic cardiomyopathy-associated mutation: MYH7, c.4135G &gt; A, p. Ala1379Thr. A diagnosis of DCRV complicated by hypertrophic cardiomyopathy and atrial flutter was made. Surgical intervention was performed, which included radiofrequency ablation, removal of abnormal muscle bundles, and ventricular septal defect repair. Intraoperative transesophageal echocardiography demonstrated the well-corrected right ventricular outflow tract. Free of early postoperative complications, the patient was discharged in sinus rhythm on the 11th day after the surgery. Unfortunately, the patient died from a sudden death 38 days following the surgery. In conclusion, the coexistence of DCRV with hypertrophic cardiomyopathy in patients is an uncommon condition. The present case highlights the importance of diagnostic imaging in the management of this disorder.

Concomitant surgery for double-chambered right ventricle and coronary stenosis

BACKGROUND AND AIMS

The clinical data of coronary artery disease in patients with double-chambered right ventricle are limited. We report an adult double-chambered right ventricle case with three-vessel coronary artery disease that was successfully treated with concomitant double-chambered right ventricle repair and coronary artery bypass grafting.

MATERIALS AND METHODS

The patient case data was extracted from hospital records.

RESULTS

The patient was the case of a 60-year-old man with a double-chambered right ventricle and three-vessel coronary artery disease. He underwent concomitant surgery comprising double-chambered right ventricle repair and coronary artery bypass grafting. Achieving cardiac arrest allowed us to obtain a good surgical view of the heavy and severely hypertrophied heart. Postoperative computed tomography revealed a feasible running course of the sequential graft, indicating that the path of the sequential graft should be clockwise (aorto-right coronary-left circumflex artery) in this unusual anatomical condition.

DISCUSSION AND CONCLUSION

We report this rare disease combination and highlight the need for careful preoperative planning in such cases.

Endothelial-to-Mesenchymal Transition as Underlying Mechanism for the Formation of Double-Chambered Right Ventricle

Double-chambered right ventricle (DCRV) is a progressive division of the right ventricular outflow tract (RVOT) often associated with a subaortic ventricular defect (VSD). The septation is caused by a mixture of hypertrophied muscle bundles and fibrous tissue, whereof the latter is of unclear pathogenesis. Our group has previously reported that flow disturbances lead to formation of fibroelastic tissue through a process called endothelial-to-mesenchymal transition (EndMT) but it is unclear whether the same mechanism exists in the RV. Tissue from patients undergoing repair of DCRV was examined to identify the histomorphological substrate of this tissue. Demographic and pre-/post-operative echocardiographic data were collected from nine patients undergoing surgery for DCRV. RVOTO tissue samples were histologically analyzed for myocardial hypertrophy, fibrosis, elastin content, and active EndMT (immunohistochemical double-staining for endothelial and mesenchymal markers and transcription factors Slug/Snail) and compared to four healthy controls. Indication for surgery were symptoms and progressive RVOT gradients. A highly turbulent flow jet through the RVOTO and VSD was observed in all patients with a preoperative median RVOT peak gradient of 77 mmHg (IQR 55.0-91.5), improved to 6 mmHg (IQR 4.5-17) postoperatively. Histological analysis revealed muscle and thick infiltratively growing fibroelastic tissue. EndMT was confirmed as underlying patho-mechanism of this fibroelastic tissue but the degree of myocardial hypertrophy was not different compared to controls (P = 0.08). This study shows for the first time that an invasive fibroelastic remodeling processes of the endocardium into the underlying myocardium through activation of EndMT contributes to the septation of the RVOT.

The morphometric study of the moderator band in Thais

A moderator band, also known as the septomarginal trabecula, is a group of muscle bundles located in the ventricle of almost all human hearts. The morphology of the moderator band has various forms and several studies have focused mostly on its structure. Thus, in the present study, we sought to study the morphology and morphometry of the moderator band and tried to rearrange the criteria based on the previous studies to classify the moderator band in Thais. The study investigated 67 formalin-fixed human hearts of both sexes obtained from Thai donors aged 24-101 years with mean age at death 69.92 years. The moderator band was evident in 66 of the 67 specimens (98.51%). The moderator band had the mean or median of overall length, thickness, distance to the base of the tricuspid valve, distance to the base of the pulmonary valve, distance to the apex of the right ventricle, the angle at the septal connection, and angle of the papillary, which were 18.9 ± 6.4 mm, 3.17 (2.04-4.55) mm, 33.0 ± 7.97 mm, 38.8 ± 9.62 mm, 56.4 ± 8.09 mm, 50 (30-105)°, 73.9 ± 30.1°, respectively. The mean distance originating point from the supraventricular crest to the anterior papillary muscle was 0.396 ± 0.07 of the distance from the base of the tricuspid valve to the apex of the right ventricle. Our present classification found that crest-like and thick moderator band with complex secondary branching at high origin (type IVc), and low origin (type IVd) were the most common subtypes. This study provided both anatomical and clinical information that should be useful in cardiac surgery, radiology, and cardiac electrophysiological interventions.

Right Ventricular Outflow Tract Obstruction in Adults: A Systematic Review and Meta-analysis

Background

Right ventricular outflow tract obstruction (RVOTO) is a cause of hemodynamic instability that can occur in several situations, including cardiac surgery, lung transplantation, and thoracic surgery, and in critically ill patients. The timely diagnosis of RVOTO is important because it requires specific considerations, including the adverse effects of positive inotropes, and depending on the etiology, the requirement for urgent surgical intervention.

Methods

The objective of this systematic review and meta-analysis was to determine the prevalence of RVOTO in adult patients, and the distribution of all reported cases by etiology.

Results

Of 233 available reports, there were 229 case reports or series, and 4 retrospective cohort studies, with one study also reporting a prospective cohort. Of 291 reported cases of RVOTO, 61 (21%) were congenital, 56 (19%) were iatrogenic, and 174 (60%) were neither congenital nor iatrogenic (including intracardiac tumour). The mechanism of RVOTO was an intrinsic obstruction in 169 cases (58%), and an extrinsic obstruction in 122 cases (42%). A mechanical obstruction causing RVOTO was present in 262 cases (90%), and 29 cases of dynamic RVOTO (10%) were reported. In the 5 included cohorts, with a total of 1122 patients, the overall prevalence was estimated to be 4.0% (1%-9%).

Conclusions

RVOTO, though rare, remains clinically important, and therefore, multicentre studies are warranted to better understand the prevalence, causes, and consequences of RVOTO.

Isolated Double-Chambered Right Ventricle - A Rare Entity

A double-chambered right ventricle (DCRV) is a rare congenital heart disease and an uncommon cause of congestive heart failure. An anomalous muscle band divides the right ventricle into two cavities: the proximal high-pressure chamber and the distal low-pressure chamber. Most cases are diagnosed and treated during childhood. Furthermore, there is a tendency for progression, if not treated early. Echocardiography is considered useful for the diagnosis of this ailment. Most of the patients have associated congenital anomalies, such as ventricular septal defect, pulmonary stenosis, and subaortic stenosis. Isolated DCRV is a rare entity. Hence, we report a case of an isolated DCRV in an adult patient.

Adult Double-Chambered Right Ventricle Associated With Ventricular Tachycardia and New-Onset Heart Failure

A double-chambered right ventricle is an uncommon form of congenital heart disease that is characterized by the division of the right ventricle into a proximal high-pressure chamber and a distal low-pressure chamber. A 70-year-old male presented to the emergency room from his outpatient doctor's office with unstable wide complex ventricular tachycardia with right axis deviation. His ventricular tachycardia was terminated using external cardioversion and intravenous amiodarone. He was subsequently found to have new-onset heart failure with a reduced ejection fraction and a right ventricular tract outflow obstruction on transthoracic echocardiography. A diagnosis of the double-chambered right ventricle was made. The patient was offered surgery to fix the anomalous tissue but he refused. He did agree to subcutaneous implantable cardioverter-defibrillator placement and was then discharged home.

Double-chambered right ventricle complicated by hypertrophic obstructive cardiomyopathy diagnosed as Noonan syndrome

We present a case of double-chambered right ventricle (DCRV) complicated by hypertrophic obstructive cardiomyopathy (HOCM) in KRAS mutation-associated Noonan syndrome. The diagnosis was incidental and made during diagnostic testing for an intradural extramedullary tumour. Spinal compression, if not surgically treated, may cause paralysis of the extremities. We decided to pursue pharmacological therapy to control biventricular obstructions and reduce the perioperative complication rate. We initiated treatment with cibenzoline and bisoprolol; the doses were titrated according to the response. After 2 weeks, the peak pressure gradient of the two RV chambers decreased from 101 to 68 mmHg, and the LV peak pressure gradient decreased from 109 to 14 mmHg. Class 1A antiarrhythmic drugs and β-blockers decreased the severe pressure gradients of biventricular obstructions caused by DCRV and HOCM. The patient was able to undergo surgery to remove the intradural extramedullary tumour, which was diagnosed as schwannoma.

Successful balloon valvuloplasty of a subpulmonic membrane associated with cor triatriatum dexter: a case report

Background

Subpulmonic membrane as a cause of right ventricular outflow tract obstruction in patients with concordant ventriculoarterial connection and intact ventricular septum is considered to be rare. Association with cor triatriatum dexter and success of subpulmonic balloon valvuloplasty have never been reported, at least to the best of our knowledge.

Case presentation

A 3-year-old Moroccan boy was referred to our tertiary care hospital with complaints of dyspnea on moderate exertion. A physical examination revealed parasternal lift, systolic thrill, and a 4/6 ejection systolic murmur, best heard over the left second intercostal space. His oxygen saturation was 99% on room air. Two-dimensional echocardiography showed a discrete circumferential membrane just below the pulmonic valve and a right atrial membrane. Continuous wave Doppler interrogation showed peak systolic pressure gradient of 85 mmHg across the subpulmonic membrane and no significant gradient across the right atrial membrane. Balloon dilation of the subpulmonic membrane was performed and the pressure gradient came down to 50 mmHg. During follow-up, he reported marked improvement in terms of exercise tolerance. Transthoracic echocardiography showed residual pressure gradient of approximately 40 mmHg across the membrane. Surgery resection of the two membranes was programmed, but he died after an extracardiac disease (appendicular peritonitis).

Conclusions

Subpulmonic membrane as an isolated cause of right ventricular outflow tract obstruction is rare. Its association with cor triatriatum dexter is even less common. The result of percutaneous balloon valvuloplasty of subpulmonic membrane is an interesting alternative while waiting for surgery. Surgery is currently the preferred modality of treatment with the resection of both right atrial and subpulmonic membranes.

Redo Valve-Sparing Root Replacement for Delayed Cusp Derangement From Ventricular Septal Defect

A 28-year-old man with ventricular septal defect, double-chambered right ventricle with associated right ventricular outflow tract obstruction, and anomalous right coronary artery underwent resection of the double-chambered right ventricle, transaortic ventricular septal defect repair, and unroofing of anomalous right coronary artery. Two years later, he returned with delayed presentation of ventricular septal defect flow funnel-related aortic cusp prolapse and symptomatic severe aortic regurgitation. He underwent reoperative valve-sparing aortic root replacement and aortic cusp repair with an excellent outcome.

Origins and consequences of congenital heart defects affecting the right ventricle

Congenital heart disease is a major health issue, accounting for a third of all congenital defects. Improved early surgical management has led to a growing population of adults with congenital heart disease, including patients with defects affecting the right ventricle, which are often classified as severe. Defects affecting the right ventricle often cause right ventricular volume or pressure overload and affected patients are at high risk for complications such as heart failure and sudden death. Recent insights into the developmental mechanisms and distinct developmental origins of the left ventricle, right ventricle, and the outflow tract have shed light on the common features and distinct problems arising in specific defects. Here, we provide a comprehensive overview of the current knowledge on the development into the normal and congenitally malformed right heart and the clinical consequences of several congenital heart defects affecting the right ventricle.

A Membranous Septal Aneurysm Causing Right Ventricular Outflow Tract Obstruction in an Adult

We describe a case of a 69-year-old female referred for the evaluation of exertional dyspnea, with a small membranous ventricular septal defect (VSD) and right ventricle (RV) outflow tract obstruction. Using transthoracic echo was diagnosed VSD with left to right shunting and transesophageal echo (TEE) was used to a better anatomical characterization. TEE showed a perimembranous subaortic VSD that developed a high-velocity flow in RV. Pulmonary valve appears normal and right ventricular infundibular hypertrophy or double-chambered RV was excluded from the study. Furthermore, TEE showed a malaligned VSD and the presence of perimembranous mobile tissue protruding in RV. We hypothesized that this tissue can be attributed to broken septum aneurysm and protruding during systole, it causes a dynamic RV output tract obstruction.

[Isolated double-chambered right ventricle (DCRV): a case study conducted at the National University Hospital CNHU-HKM in Cotonou, Benin]

Le ventricule droit à double chambre (VDDC) est une malformation cardiaque rare dans laquelle le ventricule droit est divisé en deux chambres par une bande musculaire anormale. Il est associé dans 80 à 90% à d'autres malformations. L'expression clinique est variée et dépend de l'importance de l'obstruction intraventriculaire. Nous rapportons l'observation d'une adolescente de 16 ans, présentant une forme isolée de VDDC révélée par des syncopes à répétition. Le diagnostic est fait par l'échocardiographie Döppler. La résection chirurgicale de la bande musculaire anormale a été faite avec succès.

Surgical treatment for double-chambered right ventricle in a septuagenarian

The majority of patients with double-chambered right ventricle present during childhood; it is rarely treated in adults. We report the case of a 71-year-old woman who presented with mild fatigue for 2 years. Investigation of an ejection systolic murmur revealed a double-chambered right ventricle with a peak gradient of 147 mm Hg across the right ventricular outflow tract. Substantial right ventricular muscle bundle resection and augmentation of the right ventricular outflow tract with a bovine pericardial patch were performed after a right ventriculotomy.

Role of Echocardiograghy in Treating a Case of Double Chamber Right Ventricle with Delayed Presentation

The clinical diagnosis of double chamber right ventricle (DCRV) is not straightforward. Clinical history, clinical examination, 12-lead electrocardiogram, chest X-ray, and Echocardiography (echo) contribute to morphological diagnosis. Cardiac catheterization is essential for hemodynamic evaluation. A thorough presurgical workup helps the cardiac surgeon to choose the appropriate surgical approach and timing of surgery in an individual case. We present a case of a DCRV who presented to us in the fifth decade of life. Echo confirmed the morphological diagnosis and cardiac catheterization complemented the exact pull back gradient across the obstruction in the right ventricle. This patient was suggested muscle bundle resection and ventricular septal defect closure using right atrial approach.

Isolated Double-chambered Right Ventricle with Intact Interventricular Septum

Double-chambered right ventricle (DCRV) is a developmental cardiac anomaly in which anomalous muscle bundles divide the right ventricular (RV) cavity into two chambers. It is usually associated with other congenital cardiac defects, of which ventricular septal defect is the most common association. Isolated DCRV with an intact interventricular septum is very rarely reported. It manifests itself usually in adolescence and adults as the obstruction progresses gradually. It is important to recognize this anomaly as it can progress to severe RV failure if unaddressed. We report a 13-year-old male who presented to us with an isolated DCRV. He successfully underwent a resection of the RV cavity anomalous muscle bundles. We also stress on the utility of transesophageal echocardiography intraoperatively which accurately delineates the location of the muscle bundles and helps in evaluating the adequacy of resection postsurgery.

Echocardiographic Evaluation of the Right Heart

The appropriate use of echocardiography may reduce the need for invasive diagnostic cardiac procedures. The right side of the heart has recently gained interest among cardiologists as it became clear that abnormalities of the right heart morphology and function are associated with increased morbidity and mortality. Echocardiography is easy to perform, relatively cheap, readily available and do not pose the risk of ionizing radiation. Conventional 2D and, more recently, 3D echocardiography provides pertinent anatomic and physiologic information about the right side of the heart. Because of the advantages and simplicity of echocardiography it continues to be an excellent tool for evaluating the structure and function of the right side of the heart. This review outlines the uses of echocardiography in evaluating the right heart structure and function.

Double-Chambered Right Ventricle in Adulthood

Patients with double-chambered right ventricle presenting with symptoms in adulthood are rare. From 1990 to 2004, 4 adults and 9 children with double-chambered right ventricle underwent surgical correction. The surgical results and clinical data of the adults were compared with those of the pediatric patients. All adult patients had dyspnea on exertion, 3 children showed growth delay but the others were asymptomatic. The mean age at operation was 44.5 ± 6.3 years in adults and 5.2 ± 1.9 years in children. The mean pressure gradient between the anatomically lower right ventricle and the pulmonary artery was significantly higher in adults than in children (91.8 ± 14.1 vs. 42.2 ± 5.9 mm Hg). The pulmonary-to-systemic flow ratio in adults was significantly lower than in pediatric patients (1.2 ± 0.2 vs. 1.8 ± 0.3). All adults and 8 of the 9 children survived. There were no late deaths or re-operations, and all survivors were in New York Heart Association functional class I. Surgical correction of double-chambered right ventricle in adults gave satisfactory midterm results although right ventricular outflow tract obstruction and clinical symptoms were severe in these patients.

Successful Catheter Ablation for Paroxysmal Atrial Fibrillation in a Patient with Double-chambered Right Ventricle

We herein describe an adult case of double-chambered right ventricle (DCRV) with symptomatic drug-intolerant paroxysmal atrial fibrillation (PAf). The woman was referred to undergo radiofrequency ablation (RFA), and mapping of the pulmonary veins (PVs) demonstrated that a spontaneous spike potential originating from the left inferior PV (LIPV) induced sustained Af in the second procedure. Accordingly, the LIPV was regarded as the arrhythmogenic PV. Since complete isolation of the PVs, the sinus rhythm has been maintained for at least two years. This is the first report to describe that RFA for drug-intolerant PAf was useful in a patient with DCRV.

Surgical Outcomes and Postoperative Prognosis Beyond 10 Years for Double-Chambered Right Ventricle

Double-chambered right ventricle (DCRV) is a rare condition. Stenosis of DCRV is progressive, and early surgical intervention is recommended for patients whose symptoms and/or pressure overload of right ventricular (RV) inflow are progressive. However, there are few data regarding the postoperative course of DCRV, and the surgical indications for asymptomatic patients remain to be determined. We retrospectively investigated 38 consecutive patients who were diagnosed with DCRV and underwent surgical intervention from 1981 to 2009. Moreover, we identified 29 patients in whom long-term follow-up transthoracic echocardiographic data were available and investigated the postoperative recurrence of DCRV by evaluating the systolic pressure of RV inflow before, immediately, and in the long term after surgical intervention. The mean follow-up period was 11.0 ± 8.8 years. There were no deaths and no surgical reinterventions during the long-term follow-up period. Among 29 patients with long-term follow-up echocardiographic data, there was no recurrence of DCRV. In these patients, the systolic pressure of RV inflow by echocardiography before, immediately, and long-term after surgical intervention was 80 ± 26, 30 ± 11, and 25 ± 6 mm Hg, respectively. In conclusion, the surgical outcomes and postoperative prognosis beyond 10 years of DCRV are favorable, and neither recurrence of DCRV nor fatal arrhythmias develop during the long-term follow-up period.

Double chambered right ventricle with ventricular septal defect in adults: case series and review of the literature

Double-chambered right ventricle (DCRV) is an uncommon congenital anomaly in which anomalous muscle bands divide the right ventricle into two chambers; a proximal high-pressure and distal low-pressure chamber. It may be associated with mid right ventricular obstruction. It is commonly associated with other congenital anomalies, most frequently perimembranous ventricular septal defect (PM-VSD). We herein present 5 adult patients with concomitant DCRV and PM-VSD who varied in their symptomatic presentations and the ways of management.

A case of asymptomatic isolated double-chambered right ventricle in an adult man

Double-chambered right ventricle is a rare congenital heart disease. An anomalous muscle band divides the right ventricle into two cavities, causing a variable degree of obstruction. Most cases of double-chambered right ventricle are diagnosed and treated during childhood, whereas cases of initial presentation during adulthood are very rare. We report a case of asymptomatic isolated double-chambered right ventricle incidentally found in an adult man.

Discrete subpulmonic membrane in association with isolated severe pulmonary valvar stenosis

Background

Subpulmonic membrane as a cause of right ventricular outflow tract obstruction in patients with concordant ventriculoarterial connection and intact ventricular septum is considered to be rare.

Case presentation

A 7 – year – old boy was referred to a tertiary care hospital with complaints of dyspnea on moderate exertion and palpitations of about 2 years duration. Physical examination revealed parasternal lift, systolic thrill and a 4/6 ejection systolic murmur, best heard over the left 2^nd intercostal space. His oxygen saturation was 88% on room air. Two-dimensional echocardiography showed a thickened pulmonary valve with fused leaflets that show severe systolic doming. There was a discrete subpulmonic membrane about 1.3 cm below the pulmonary valve annulus. Continuous wave Doppler interrogation showed peak systolic pressure gradient of 185 mmHg across the pulmonary valve. Balloon dilation of the pulmonary valve was performed and the pressure gradient came down to 50 mmHg. Follow-up transthoracic echocardiography showed residual pressure gradient of about 50 – 60 mmHg across the pulmonary valve. The residual pressure gradient appeared to be mainly subvalvar, as seen on the continuous wave Doppler tracing. The patient reported marked improvement in terms of exercise tolerance and subjective symptoms.

Conclusions

Association of subpulmonic membrane with severe pulmonary valvar stenosis, concordant ventriculoarterial connection and intact ventricular septum is rare. When it occurs, the result of percutaneous valve dilation may be suboptimal.

Double-chambered right ventricle: a review

A double-chambered right ventricle is a rare heart defect in which the right ventricle is separated into a high-pressure proximal and low-pressure distal chamber. This defect is considered to be congenital and typically presents in infancy or childhood but has been reported to present rarely in adults. It can be caused by the presence of anomalous muscle tissue, hypertrophy of the endogenous trabecular bands, or an aberrant moderator band; all of which will typically result in progressive obstruction of the outflow tract. In this paper, we will discuss the general anatomy of the right ventricle, the relevant embryology of the heart, and the presentation, diagnosis, and treatment of a double-chambered right ventricle.

Not all obstructive cardiac lesions are created equal: double-chamber right ventricle in pregnancy

Double-chambered right ventricle (DCRV) is a rare form of right ventricular outflow tract (RVOT) obstruction accounting for approximately 1% of patients with congenital heart disease. It consists of an anomalous muscle bundle that divides the right ventricle usually between the sinus (inlet) and the infundibulum (outlet). This division creates a proximal chamber with high pressure and a distal chamber with low pressure. The hemodynamic obstruction of the RVOT is usually an acquired phenomenon, however the substrate for the anomalous muscle bundle is likely congenital. The diagnosis of DCRV should be considered in the young patient with an elevated right ventricular systolic pressure and intracavitary gradient. Echocardiography and cardiac MRI are the principal diagnostic tools for the assessment of DCRV. This entity is often misdiagnosed as pulmonary hypertension in the young patient, and can often go overlooked and untreated for many years. Definitive therapy involves surgical resection of the muscle bundle. This can often be curative and if done in a timely fashion, may prevent right ventricular remodeling. We describe the unique diagnostic dilemma, the course and management of a young adult with DCRV during pregnancy.

Outcomes of surgical repair of double-chambered right ventricle

BACKGROUND

We reviewed our experience with surgical repair of double-chambered right ventricle and long-term outcome.

METHODS

From November 1970 to February 2008, repair of double-chambered right ventricle was performed in 61 patients (31 males). The median age was 13 years (interquartile range, 2 months to 64 years); 10 patients were infants (16%). Mean preoperative right ventricular outflow tract pressure gradient was 67±37 mm Hg. An associated ventricular septal defect was present in 50 patients (82%).

RESULTS

There were 2 (3%) early deaths due to persistence of low cardiac output postoperatively, despite complete relief of the right ventricular gradient. The overall mean postoperative gradient was 2±4.5 mm Hg. Late follow-up was complete in 92% (mean, 7.4±7.9 years; maximum, 37 years). Late survival was 90% at 10 years. There were 3 late deaths due to heart failure in 2 patients and sudden death in 1 patient, all occurring before 1997. No patients required reoperation for residual or recurrent right ventricular obstruction.

CONCLUSIONS

Surgical correction of double-chambered right ventricle results in excellent functional and hemodynamic long-term results, with complete relief of the right ventricular obstruction. The presence of a double-chambered right ventricle should be considered in anomalies with high or persistent right ventricular outflow tract obstruction.

Spontaneously healed membranous type ventricular septal defect with malaligned interventricular septal wall and double-chambered right ventricle in a 56-year-old patient

A 56-year-old male presented with resting dyspnea and chest discomfort for several years. During transthoracic and transesophageal echocardiography, a spontaneously healed membranous type ventricular septal defect (VSD) with malaligned interventricular septal wall, aneurysmal changes, a subaortic ridge and a double-chambered right ventricle (DCRV) was observed. When combined with DCRV, VSD with malalignment between the outlet and trabecular septa was associated with tetralogy of Fallot. The subaortic ridge was due to turbulent flow caused by the malalignment-type VSD. The VSD with malaligned interventricular septal wall can be developed after aneurismal changes of a perimembranous VSD. We report here in the unusual case of a 56-year-old patient who had a pathology complex comprising DCRV, subaortic ridge, spontaneously healed membranous type VSD with malaligned interventricular septal wall, and survived with surgical treatment.

Natural internal banding in adult patients with a large ventricular septal defect and a preserved pulmonary vascular system

OBJECTIVE

Hypertrophied anomalous muscle bands (AMBs) in the right ventricular outflow tract (RVOT) may develop in the context of ventricular septal defects (VSDs) and limit persistent pulmonary overflow. In adult patients with a large VSD, persistent AMBs in the RVOT therefore can simulate the role of an externally placed pulmonary artery band. We termed such alterations natural internal bands (NIBs). Our goal was to establish the morphologic nature of the obstructive muscular lesions of the RVOT in patients with a large VSD.

METHODS

Patients who underwent operations for a large VSD in our center, which has a high volume of adult patients with congenital defects, were retrospectively reviewed, and the nature of the NIBs in these patients was documented. All patients underwent transthoracic echocardiography and cardiac catheterization evaluations preoperatively and at postoperative month 3. Histopathologic examination of the AMBs was performed.

RESULTS

Of 96 adult patients who underwent operations for a large isolated VSD (mean defect size, 16.9 ± 3.5 mm), 16 patients had a hemodynamically significant NIB. Two different patterns of obstruction were found. Ten of the 16 patients revealed an os infundibulum morphology, and 6 patients revealed systolic bulging of the conal septum. Four of the patients with os infundibulum also had classic tetralogy-type septal malalignment. The mean peak systolic gradient on the RVOT was 56.5 ± 17.2 mm Hg and 53.6 ± 12.3 mm Hg in the patients with os infundibulum and in the patients with systolic bulging of the conal septum, respectively. Surgical repair of the VSD was completed successfully in all patients. Resection of the os infundibulum was performed concomitantly in patients with os infundibulum. At the third postoperative month, the mean peak systolic gradient was 16.8 ± 3.5 mm Hg in patients with os infundibulum and 26 ± 5.9 mm Hg (range, 20-35 mm Hg) in patients with systolic septal bulging.

CONCLUSIONS

Some mechanisms in adult type VSDs are essential for protecting the pulmonary vasculature. We tried to review these protective mechanisms: hypertrophied AMBs and NIBs.

Isolated double-chambered right ventricle in a young adult

Double-chambered right ventricle (DCRV) is a rare congenital heart disorder in which the right ventricle is divided by an anomalous muscle bundle into a high pressure inlet portion and a low pressure outlet portion. We report a case of isolated DCRV without symptoms in adulthood, diagnosed through echocardiography, cardiac catheterization and cardiac magnetic resonance imaging.

Surgical repair of double-chambered right ventricle in adulthood

The aim of this study was to investigate a rare subset of adult patients with double-chambered right ventricle, pertaining to clinical presentation, rhythm disturbances, surgical approach, and results of surgical repair. A retrospective review of our records revealed that 14 adults had undergone surgical repair of double-chambered right ventricle from 1990 to 2010. Their median age was 25.5 years, and their median weight was 50 kg. Patients presented with various symptoms, the most common being dyspnea on exertion. The mean systolic pressure gradient across the obstruction was 69.8 ± 23.1 mm Hg. The most common associated anomaly was ventricular septal defect. Significant rhythm disturbances were present in 4 patients. Transatrial repair was undertaken in 5 patients, a combined transatrial and transpulmonary approach was used in 4, and a right ventriculotomy in 5. There was no mortality at a median follow-up of 5.1 years. A mild right ventricular outflow tract gradient was noted in 2 patients. Medical management was required for rhythm disturbances in 2 patients. Double-chambered right ventricle can present in adulthood, often with vague symptoms. The midterm results of surgical correction are satisfactory. Long-term follow-up is necessary to detect late arrhythmias.

Characteristics of double-chambered right ventricle in adult patients

BACKGROUND/AIMS

This study evaluated the clinical features of double-chambered right ventricle (DCRV) in adults. Most cases of DCRV are diagnosed and treated during childhood. Consequently, very few reports include cases in which its clinical characteristics are evident in adults.

METHODS

We reviewed the clinical data for 10 adult patients (age > or = 18 years) with DCRV.

RESULTS

Electrocardiogram showed right ventricular hypertrophy in 3 DCRV patients. All cases were associated with ventricular septal defect (VSD; 7 for perimembranous, 2 for muscular outlet, and 1 for the subarterial type). Surgical correction was done for 7 DCRV patients all of whom survived operations. Their follow-up echocardiogram showed the pressure gradient in their right ventricle was significantly decreased from 69.4 +/- 17.2 mmHg preoperatively to 10.2 +/- 5.0 mmHg postoperatively (p < 0.05). In the short-term follow-up, there was no significant increase in the pressure gradient in the right ventricle.

CONCLUSIONS

There are lots of cases of DCRV that are not diagnosed accurately in adults. In our experience, all DCRV cases had VSD and surgical correction of these cases showed excellent results. Therefore, accurate diagnosis of DCRV is necessary so that DCRV is not overlooked and operations are enabled within an appropriate time.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: outflow tract obstruction, coarctation of the aorta, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part II of the guidelines includes recommendations for the care of patients with left ventricular outflow tract obstruction and bicuspid aortic valve disease, coarctation of the aorta, right ventricular outflow tract obstruction, tetralogy of Fallot, Ebstein anomaly and Marfan's syndrome. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts that are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

An elderly case of right ventricular outflow obstruction precisely diagnosed and successfully treated with surgical repair

Congenital diseases causing an obstruction of the right ventricular outflow are difficult to precisely diagnose, especially in elderly patients. Here, we describe a 76-year-old woman who presented to our hospital with shortness of breath on exertion and was finally diagnosed as infundibular pulmonary stenosis by multiple modalities. Surgery was successfully performed and the symptom was relieved. This case underscored the usefulness of multiple modalities for the precise assessment of the right ventricular outflow obstruction and the effectiveness of surgery even in elderly patients with infundibular pulmonary stenosis.

Isolated double-chambered right ventricle presenting in adulthood

We report the case of a 55-year-old woman who was admitted for exertional chest pain with dyspnea. The patient was diagnosed with an isolated double-chambered right ventricle (DCRV) without associated congenital anomalies. Most cases of DCRV are diagnosed at a young age and commonly associated with VSD; isolated DCRV in adults is extremely rare.