The double-chambered right ventricle: a case report in an adult patient

Introduction The-double chambered right ventricle (DCRV) is a rare distinctive anatomic entity with both congenital and acquired components, wherein abnormally located or hypertrophied muscular bands divide the right ventricle into a proximal high-pressure and a distal lower pressure chambers - even to the point of mid-ventricular obstruction. As the DCRV is very often associated with other congenital cardiac defects, such as a perimembranous ventricular septal defect (PM-VSD), it is usually diagnosed in infancy and childhood. However, it may remained unrecognised until adulthood, when the patient presents with atypical symptoms mimicking common acquired cardiac diseases. In the current case report, we present an adult patient with DCRV that underwent a complex cardiac surgery, not only for the primary defect, but also for the coexisting cardiac pathologies. Methods A 63yr old female patient, with a known medical history of an uncorrected VSD, presented to our hospital with intense chest discomfort and dyspnea on minimal exertion (NYHA III). The laboratory exams showed mild troponin increase, whilst the TTE verified the presence of a VSD, but also revealed the existence of a DCRV with normal function and dimensions, a severely stenosed aortic valve, a severely regurgitant mitral valve and a left ventricle with preserved EF. After performing a coronary angiography that showed right coronary artery disease and common origin of the left and right coronary arteries from a single ostium, the patient was scheduled for surgery. Intraoperatively, the TOE examination showed a normally functioning hypertrophied RV, with abnormal muscular bands (AMB) that cross its cavity and cause nearly total RVOT obstruction and turbulent flow. The usage of a Swan-Ganz catheter verified the existence of two separate chambers with a pressure gradient of almost 100mmHg inside the RV and set the diagnosis of a DCRV. Furthermore, the known VSD was more specifically a PM-VSD with left to right flow between the LVOT and the proximal supra-systematic chamber of the RV, because of the simultaneous severe aortic valve stenosis. Results The patient underwent excision of the AMB through a small right ventriculotomy, mitral valve repair with an Alfieri stitch transaortically and aortic valve replacement with root enlargement. No graft was placed to the RCA because of the poor distal target. Despite the successful excision of the AMB and the release of the intracavitary obstruction, the separation from the CPB was very difficult due to biventricular, but mostly RV dysfunction. The patient was placed on V-A ECMO and transferred to the CICU. Discussion In this case report, we showed that a rare congenital cardiac disease (DCRV) can remain masked until adulthood, when the patient becomes finally symptomatic but with atypical symptoms. Definitive treatment is surgery and generally has an excellent prognosis. However, we should be very careful before attempting to derange the balances that the RV has set to itself until then.