Influence of RV restrictive physiology on LV diastolic function in children after tetralogy of Fallot repair

Abstract

Background: Restrictive right ventricular (RV) physiology is a common finding after tetralogy of Fallot repair. Via diastolic ventricular interaction, RV filling characteristics may influence left ventricular (LV) filling. The aim of this study was to analyze the effect of RV diastolic physiology on LV diastolic properties.

Methods: This was a retrospective study including 112 pediatric patients after tetralogy of Fallot repair who underwent full echocardiographic evaluations. Restrictive RV physiology was defined as the presence of end-diastolic forward flow in the main pulmonary artery as detected in at least three consecutive cardiac cycles. RV and LV diastolic function was assessed by analyzing mitral or tricuspid inflow patterns, pulmonary venous flow traces, and pulsed tissue Doppler velocities at the tricuspid and mitral annuli.

Results: The mean age at the time of study was 12.9 ± 3.2 years. Restrictive RV physiology was identified in 58 of 112 patients (52%). Patients with RV restriction had larger right atrial and RV dimensions, as well as increased left atrial length and left atrial indexed volume compared with nonrestrictive patients. No differences were found in LV dimensions. Although parameters reflecting early LV diastolic filling (mitral E velocity, lateral annular E' velocity, isovolumetric relaxation time, and E/E' ratio) were not different between the restrictive and nonrestrictive patients, those reflecting late filling were different, with a significantly higher pulmonary venous A-wave reversal velocity and duration in the restrictive group (P < .001). Also, the difference between pulmonary venous A-wave reversal and mitral valve A-wave duration was higher in the restrictive group (P = .0007).

Conclusions: End-diastolic forward flow in the main pulmonary artery is associated with larger RV dimensions in pediatric patients with postoperative tetralogy of Fallot. The presence of end-diastolic forward flow was not associated with other differences in RV diastolic parameters but with more pronounced pulmonary venous reversals and larger left atrial size. This indicates that ventricular diastolic interaction affects LV filling pressures.