Double-Chambered Right Ventricle

Double-chambered right ventricle (DCRV) is a rare congenital heart defect presenting with hypertrophied muscle bundles¹.  Hypertrophy of muscle bundles, trabecular bands, and moderator bands can result in a right outflow tract obstruction². DCRV is often associated with coexisting anomalies such as a membranous VSD³. It can also occur following the repair of a ventricular septal defect or Tetralogy of Fallot, or develop de novo in infancy, childhood, and, less commonly, adulthood. Surgical intervention is indicated for patients with moderate to severe right outflow tract obstruction¹ or those experiencing symptoms of heart failure or exercise limitations³. This video highlights the case of an adolescent male undergoing repair of a DCRV.

Double-chambered right ventricle (DCRV) is a rare congenital heart defect presenting with hypertrophied muscle bundles1.  Hypertrophy of muscle bundles, trabecular bands, and moderator bands can result in a right outflow tract obstruction2. DCRV is associated with coexisting anomalies such as a membranous VSD3. It can also occur following the repair of a ventricular septal defect or Tetralogy of Fallot, or develop de novo in infancy, childhood, and, less commonly, adulthood. Surgical intervention is indicated for patients with moderate to severe right outflow tract obstruction1 or those experiencing symptoms of heart failure or exercise limitations3. This video highlights a case of an adolescent male who presented with a 3/6 holosystolic murmur. His echocardiogram demonstrated a small sub aortic perimembranous ventricular septal defect, a subaortic membrane causing discrete LVOTO, trace aortic insufficiency, and a double-chambered right ventricle. He presented at 11 years of age for surgical subaortic membrane resection, myotomy, RVOT muscle bundle resection, and VSD patch closure.

Under general anesthesia, cardiopulmonary bypass was initiated in the standard fashion, maintaining normothermia. After the heart was arrested with Del Nido cardioplegia, a reverse hockey stick aortotomy was made and extended down towards the noncoronary cusp. Stay sutures were placed. A subaortic membrane, that didn’t impinge on the aortic valve or mitral valve leaflets, was freed from the left ventricular outflow tract using blunt dissection. For augmentation of the left ventricular outflow tract, a limited myectomy was performed. A limited right ventriculotomy was performed preserving the pulmonary valve. An ample amount of RV muscle bundles was resected, and a small VSD was viewed. CorMatrix was cut to the appropriate dimensions, and, using a 5-0 Prolene suture, the VSD was closed in a pledgeted fashion. Several large breaths were given and no residual ventricular septal defect was revealed. The right ventriculotomy was then augmented with a CorMatrix patch for closure using 5-0 Prolene in a running continuous fashion. The aortotomy was then closed; the patient was successfully weaned off CPB, and after adequate hemostasis, the chest was closed in the standard fashion.

Cross clamp time was 38 minutes and cardiopulmonary bypass time was 55 minutes. Post-operative echo showed no residual septal defect, no RVOT residual stenosis, trivial pulmonary valve insufficiency, trivial aortic valve insufficiency, and normal left and right ventricular cavity size and systolic function. The patient was extubated in the OR and sent to the CVICU for continual recovery.

This video provides an overview of DCRV, outlining its surgical repair and etiology. In DCRV, the hypertrophied muscle bundles divide the right ventricle into two chambers2. The proximal chamber will be under high-pressure and the distal chamber under low-pressure1. DCRV can lead to subinfundibular right ventricular outflow tract obstruction, but it may result from turbulent flow caused by another obstruction in the outflow tract. The most effective treatment for DCRV is surgical intervention, as demonstrated in this video. Surgical indications include symptoms of heart failure or an increased pressure gradient2. There are different surgical approaches for resection of the muscle bands including a right atriotomy, right ventriculostomy, or a combined transatrial-transpulmonary repair4. A right atriotomy was demonstrated in this video. Surgical correction of DCRV has a good long-term prognosis and relief of symptoms5.

No disclosures of conflict.

No acknowledgements

1. Patibandla, S. (2024, January 19). Double-chambered right ventricle. StatPearls [Internet]. https://www.ncbi.nlm.nih.gov/books/NBK546625/ 2. Loukas, M., Housman, B., Blaak, C., Kralovic, S., R. Shane Tubbs, & Anderson, R. H. (2013). Double-chambered right ventricle: a review. 22(6), 417–423. https://doi.org/10.1016/j.carpath.2013.03.004 3. Patibandla, S., & Kyaw, H. (2022). Double Chambered Right Ventricle. PubMed; StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK546625/ 4. Moustafa, S., Patton, D. J., Alvarez, N., Mansour Al Shanawani, Khalid AlDossari, Connelly, M. S., Prieur, T., & Farouk Mookadam. (2015). Double Chambered Right Ventricle with Ventricular Septal Defect in Adults: Case Series and Review of the Literature. Journal of Cardiovascular Ultrasound, 23(1), 48–48. https://doi.org/10.4250/jcu.2015.23.1.48 5. Said, S. M., Burkhart, H. M., Dearani, J. A., O’Leary, P. W., Ammash, N. M., & Schaff, H. V. (2012). Outcomes of Surgical Repair of Double-Chambered Right Ventricle. The Annals of Thoracic Surgery, 93(1), 197–200. https://doi.org/10.1016/j.athoracsur.2011.08.043