Abstract 13075: Wave Intensity Analysis of the Pulmonary Artery in Postoperative Tetralogy of Fallot: Impact of Residual Pulmonary Stenosis on Pulmonary Regurgitation and Ventricular Function
Background: Pulmonary regurgitation (PR) and the resultant right ventricular (RV) dilatation/dysfunction are important determinants of long-term outcome in patients with repaired tetralogy of Fallot (TOF). Although residual pulmonary stenosis (PS), which often coexists with PR, increases RV pressure load, it may help reduce PR and prevent RV dilatation. A certain degree of PS might even enhance RV function and thereby enhance left ventricular (LV) function via interventricular interaction. To test these hypotheses, we investigated pulmonary wave front behavior by wave intensity analysis (WIA) and interventricular interaction by pressure-volume relationships.
Methods: WI of the peripheral pulmonary arteries (PA) and LV pressure-volume relationships were computed during cardiac catheterization in 31 patients with repaired TOF and 28 control subjects. WIA yielded 3 major components: (1) compression and acceleration wave (W1), which reflects RV-PA interaction; (2) negative wave (WN), which represents intensity of wave reflection; and (3) expansion and deceleration wave (W2), which denotes regression in the antegrade blood flow and reflects the degree of PR.
Results: While there was no significant difference in W1 between the 2 groups, both WN and W2 were markedly higher in patients with repaired TOF than in the controls, consistent with increases in both wave reflection and PR in repaired TOF. Multivariate regression analysis revealed that pulmonary wedge pressure and PR severity positively correlated with W2, while PS severity negatively correlated with W2 (standardized β: 0.42, 0.35, –0.35, p = 0.005, 0.037, 0.025, respectively). Residual PS-induced increases in RV pressure up to half of the LV pressure enhanced RV contractility, which was positively correlated with LV contractility (p = 0.035). Importantly, enhanced RV contractility induced by PS resulted in the significantly lower serum levels of aldosterone (p = 0.025).
Conclusions: These data suggest that residual PS reduces PR, enhances RV and LV contractility, and possibly prevents abnormal hormonal activation, and that angioplasty for residual PS may be disadvantageous in some patients with repaired TOF. WIA is useful as a guide to optimize pulmonary intervention in repaired TOF.
- © 2013 by American Heart Association, Inc.