A Case of Adult Double-Chambered Right Ventricle Causing Severe Right Ventricular Outflow Tract Obstruction: A Perioperative Perspective

                                  http://www.mathewsopenaccess.com/surgery-Vol-1-Iss-1.html

Double-chambered right ventricle (DCRV) is a rare, congenital heart disease often caused by anomalous muscle bands that can obstruct or even divide the right ventricle into high and low pressure chambers leading to progressive right ventricular outflow (RVOT) obstruction. It is seen in only 0.5-2% of all congenital heart diseases and associated with VSD in 75-90% of cases. DCRV is typically diagnosed and treated during childhood, with rare diagnoses made in adulthood. There does not appear to be a genetic component. It can be difficult to diagnose, especially in the adult patient, due to limitations in modern imaging of the right ventricle. We report a case of a 63-year-old female who returned to the United States for the first time since diagnosis of ventricular septal defect (VSD) at age three. Her symptoms of dyspnea on exertion and fatigue were attributed to right ventricular hypertrophy with obstruction. The patient was scheduled for VSD closure and myomectomy of RVOT utilizing cardiopulmonary bypass (CPB). 

The severe nature of her disease required careful planning of her perioperative management to maintain stable hemodynamics and prevent cardiovascular collapse. Intra-operatively the patient was found to have a myocardial morphology consistent with DCRV. Successful selection and timing of anesthetics, invasive monitoring, vasopressors, and inotropes facilitated an uneventful hospital course. Dis charge occurred on post-operative day four without adverse sequelae. While previous reports have focused on the surgical findings and procedures, very few case reports in the literature have concentrated on the anesthetic management of this complicated congenital condition. This is the only known case that did not require a significant fluid load following induction and initiation of positive pressure ventilation. With careful planning it was even possible to remove autologous blood to minimize transfusion requirements. This report will aid the perioperative team in recognition of characteristic findings in DCRV and offer insight into perioperative management. 

The patient is a 63-year-old female with a known history of uncorrected, congenital VSD who returned to the United States for evaluation of increasing shortness of breath during light activity. Her parents, both missionaries in Tanzania, brought the patient to the U.S. at age three for evaluation of a mur-mur noted at birth. At the time, it was deemed unnecessary to intervene, and the patient experienced a largely unrestricted life in Africa completing missionary work herself. Over the last few years the patient noted a few episodes of atypical non-exertional chest pain as well as progressive exertional dyspnea. The patient’s medical history included only known congenital VSD and right ventricular hypertrophy. She had not undergone prior surgeries. She did not use tobacco, alcohol or illicit drugs and her family history includes heart failure and stroke. The patient underwent extensive cardiac evaluation upon returning to the United States including transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), cardiac magnetic resonance imaging (MRI), right and left heart catheterization with ventriculography, as well as electrocardiogram (ECG). The patient was noted to have severe narrowing of the RVOT (Figure 1) with severely increased velocity of 5.45 m/sec and severe pressure gradient of 119 mm Hg across the tract.