Effects of inhaled nitric oxide on Fontan hemodynamics in adults.

The pulmonary vasculature plays a pivotal role in the nonpulsatile systemic venous return post-Fontan palliation. Elevated pulmonary vascular resistance index (PVRi) carries a worse prognosis post-Fontan, but the benefits of pulmonary vasodilators remain controversial. Moreover, the potential for worsening ventricular filling pressures with pulmonary vasodilation has been highlighted. We reviewed our experience with inhaled nitric oxide (iNO) administration during cardiac catheterization in 30 adults (age 32.7 ± 8.5 years) post-Fontan. The main findings of the study are: (1) iNO decreased pulmonary artery pressures, transpulmonary gradient, and PVRi without increasing pulmonary artery wedge pressure, (2) cardiac index was unchanged with iNO, and (3) different from acquired left heart disease, iNO did not result in further elevations in pulmonary artery wedge pressure in those with elevated ventricular filling pressures. iNO administration in adults post-Fontan was safe; whether baseline PVRi and response to iNO could be used to predict response to pulmonary vasodilators post-Fontan requires further investigation.

Echo-Doppler and strain assessment of filling pressures in adults with congenitally corrected transposition and systemic right ventricles.

AIMS: Systolic dysfunction of the systemic right ventricle (sRV) is common in adults with transposition of the great arteries and sRV. In acquired disease, diastology analysis for assessment of filling pressures (FP) is paramount in patient care. METHODS AND RESULTS: Retrospective analysis of 47 adults with sRV without prior systemic tricuspid valve surgery undergoing catheterization and echocardiography within 7 days (median -2 [-1, -3]) from January 2000 to February 2021 at our institution. Median age was 48 (31, 55) years, and 16 (34.0%) patients were female. FPs were normal in 21 patients (44.7%). Left atrial size was enlarged in most patients (83.0%) with mean indexed value 58.3 ± 23.4 mL/m2. Tissue Doppler e' was not significantly different between those with high FPs vs. normal (medial 0.07 ± 0.03 vs. 0.08 ± 0.03 m/s, P = 0.63; lateral 0.08 ± 0.04 vs. 0.08 ± 0.04 m/s, P = 0.88). E velocity and subpulmonic mitral regurgitant velocity were higher in those with high FPs (0.9 ± 0.3 vs. 0.6 ± 0.2 m/s, P = 0.005; 3.8 ± 1.1 vs. 2.8 ± 0.9 m/s, P = 0.004). Left atrial reservoir strain, sRV global longitudinal strain, and subpulmonic left ventricular strain were worse in those with high FP (18.0 ± 7.6 vs. 27.9 ± 10.2%, P = 0.0009; -13.0 ± 4.4 vs. -17.9 ± 5.0%, P = 0.002; -16.8 ± 5.7 vs. -23.0 ± 3.8%, P = 0.001). CONCLUSION: Despite the complex anatomy, FPs can be assessed non-invasively in adults with sRV without prior systemic tricuspid valve surgery. The current guideline algorithm for diastolic dysfunction in acquired heart disease has limited applicability in this population. Given the limitations of Doppler in this heterogeneous population, strain analysis can be a helpful adjunct for estimation of FPs.