Figure 3. Pulmonary valve flow quantification in a patient with tetralogy of Fallot. (A) Magnitude and phase contrast images are obtained in the proximal main pulmonary artery oblique to the pulmonary valve. (B) Volume and direction of flow is determined, and the … Pulmonary valve replacement (PVR) usually eliminates significant PR, however, optimal timing of PVR to prevent the adverse sequelae of RV dilation and dysfunction remains unclear.13 PVR usually results in dramatic decreases
in RV volumes and improvement in functional status,14 but Inhibitors,research,lifescience,medical studies have demonstrated mixed results on whether PVR improves RV systolic function.15 Newer catheter-based pulmonary valves are promising developments in patients with CHD affecting the right heart. At the current time, most percutaneous valves are Inhibitors,research,lifescience,medical placed inside existing RV-PA conduits or dysfunctional bioprosthetic valves. However, a few patients may have small
enough outflow tracts and high enough surgical risk that a percutaneous pulmonary valve could be considered in an off-label use. CMR can help determine the size Inhibitors,research,lifescience,medical of the outflow tract to identify if the patient may be a potential candidate. Delineation of the coronary artery course is essential prior to any RVOT intervention, as 5% to 10% of patients Inhibitors,research,lifescience,medical with TOF have an anomalous left coronary artery that may course across the RVOT, which could complicate possible
interventions. Tricuspid Regurgitation There are several mechanisms that lead to tricuspid regurgitation (TR) in repaired TOF patients, including annular dilation and structural valve abnormalities.16 The TR fraction may be assessed at the time of CMR and should be considered Inhibitors,research,lifescience,medical in surgical plans and the time of PVR.17 Aortic Root Dilation Patients with TOF have larger aortic roots compared to healthy controls, likely due to increased aortic flow prior to repair from shunting through the VSD and/or aorta pulmonary collateral flow that may cause volume loading of the LV. Some patients develop progressive dilation of the aortic root that can lead to significant aortic regurgitation.18 Myocardial Batimastat Fibrosis Late gadolinium enhancement (LGE) has predicted increased arrhythmic selleckbio events in patients with multiple forms of acquired heart diseases.19, 20 LGE occurs commonly in myocardial locations of prior surgery (RVOT, VSD patch). Repaired TOF patients with greater degrees of LGE are at a higher risk of sustained symptomatic arrhythmia; however, it is buy inhibitor unclear if LGE is associated with increased mortality in this patient population.