Changes in left and right ventricular longitudinal function after pulmonary valve replacement in patients with Tetralogy of Fallot

Abstract

Timing and indication for pulmonary valve replacement (PVR) in patients with repaired Tetralogy of Fallot (rToF) and pulmonary regurgitation (PR) are uncertain. To improve understanding of pumping mechanics, we investigated atrioventricular coupling before and after surgical PVR. Cardiovascular magnetic resonance was performed in patients ( n = 12) with rToF and PR > 35% before and after PVR and in healthy controls ( n = 15). Atrioventricular plane displacement (AVPD), global longitudinal peak systolic strain (GLS), atrial and ventricular volumes, and caval blood flows were analyzed. Right ventricular (RV) AVPD and RV free wall GLS were lower in patients before PVR compared with controls ( P < 0.0001; P < 0.01) and decreased after PVR ( P < 0.0001 for both). Left ventricular AVPD was lower in patients before PVR compared with controls ( P < 0.05) and decreased after PVR ( P < 0.01). Left ventricular GLS did not differ between patients and controls ( P > 0.05). Right atrial reservoir volume and RV stroke volume generated by AVPD correlated in controls ( r = 0.93; P < 0.0001) and patients before PVR ( r = 0.88; P < 0.001) but not after PVR. In conclusion, there is a clear atrioventricular coupling in patients before PVR that is lost after PVR, possibly because of loss of pericardial integrity. Impaired atrioventricular coupling complicates assessment of ventricular function after surgery using measurements of longitudinal function. Changes in atrioventricular coupling seen in patients with rToF may be energetically unfavorable, and long-term effects of surgery on atrioventricular coupling is therefore of interest. Also, AVPD and GLS cannot be used interchangeably to assess longitudinal function in rToF. NEW & NOTEWORTHY There is a clear atrioventricular coupling in patients with Tetralogy of Fallot (ToF) and pulmonary regurgitation before surgical pulmonary valve replacement (PVR) that is lost after operation, possibly because of loss of pericardial integrity. The impaired atrioventricular coupling complicates assessment of ventricular function after surgery when using measurements of longitudinal function. Left ventricular atrioventricular plane displacement (AVPD) found differences between patients and controls and changes after PVR that longitudinal strain could not detect. This indicates that AVPD and strain cannot be used interchangeably to assess longitudinal function in repaired ToF.