Novel analytical application of the pressure phase plane for evaluating pulmonary artery wave reflection in surgically repaired tetralogy of Fallot

BackgroundPulmonary artery (PA) wave reflection is a key determinant of right ventricular (RV) afterload. RV function is the most important factor determining long-term prognosis in patients with surgically repaired tetralogy of Fallot (rTOF). This study aimed to evaluate PA wave reflection in rTOF using RV pressure phase plane (PPP) analysis, and to identify the clinical, morphological, and hemodynamic characteristics associated with increased PA wave reflection in patients with rTOF. MethodsAugmentation pressure (AugPr) during late systole was quantified using the inflection point of systolic dP/dt on the PPP. The ratio of AugPr to RV systolic pressure (RVSP) was defined as the AugPr index. The study included 87 patients with rTOF (mean age, 15.9 {+/-} 10.0 years), 17 control subjects (13.3 {+/-} 6.3 years), and seven patients with pulmonary arterial hypertension (PAH) (16.4 {+/-} 11.7 years). The rTOF cohort was categorized according to surgical procedure: pulmonary valve-sparing repair (PVS, n = 5), transannular patch repair (TAP, n = 34), and the Rastelli procedure (n = 48). ResultsThe prevalence of AugPr was 0% in the control group, 100% in the PAH group, and 26.4% in the rTOF group (p < 0.0001). Among the surgical subgroups, the prevalence was 0% in PVS, 14.7% in TAP, and 41.7% in the Rastelli group (p < 0.0027). AugPr and the AugPr index were significantly higher in the Rastelli group than in the other two groups (p = 0.0447 and 0.0433, respectively). In addition, AugPr showed significant correlations with RVSP, RV outflow tract obstruction, maximal dP/dt, and pulmonary regurgitation grade (all p < 0.05). ConclusionsPA wave reflection can be clearly visualized using PPP. The Rastelli group demonstrated a higher prevalence and magnitude of PA wave reflection, suggesting a greater increase in RV afterload compared with other surgical repair types.