valve insufficiency, or RV systolic failure Hypoplastic RV Diagnostic angiography should be performed to outline sinusoidal or fistulas connections between the hypertensive RV and to the coronary arteries This angiogram is usually only 0.5 mL/kg with a slow injection with quick withdrawal of the contrast after the angiogram This technique is secondary to contrast not having oxygen present, and coronary ischemia can occur if there is RV-driven and/or RV-dependent coronary blood flow Double Chamber RV This can be a progressive lesion and is often associated with a membranous ventricular septal defect RV muscle bundles (moderator band from the lower infundibular septal region) traverse and obstruct the RVOT If diagnostic catheterization is performed, the pressures must be obtained in the RV inflow and RV outflow The RV inflow will be elevated due to the obstruction within the RV cavity, and the RV outflow will be the same as the LV if there is a nonrestrictive VSD and/or the same as the main pulmonary artery if there is a normal pulmonary valve Postoperative Rastelli Patients When there is significant RVOT obstruction (Fig 17.6) and/or RV dysfunction, one often sees a significant decrease in the saturation between the SVC and RV, due to a very low coronary sinus saturation (often