Abstract 15612: The Effect of Right Ventricular Volume Overload on Ventricular Deformation - Differential Response in Patients with Atrial Septal Defect and after Tetralogy of Fallot Repair.
Background: Right ventricular (RV) volume overload results in RV dilatation. RV strain (S) and strain rate (SR) imaging allow a quantitative assessment of RV function which is influenced by RV geometry and loading conditions.
Aim: Study the effect of RV volume loading on RV myocardial deformation and develop potential methods correcting for the effect of RV size on RV deformation.
Methods and results: Seventy patients were studied: 40 patients after ToF repair, 10 patients with unrepaired ASD and 20 age matched controls. The controls and ToF patients underwent an echocardiography at the time of a clinically indicated MRI; the ASD patients underwent a routine clinical echocardiogram including RV volume calculations using 2-D based 3-D reconstruction (Ventripoint, USA). Ultrasound images were acquired using a GE Vivid 7 (GE Ultrasound, USA). For RV longitudinal deformation the RV lateral S and SR were obtained from an apical 4 chamber view using speckle tracking technique. Deformation parameters were lower for ToF patients compared to controls: S -23±5% vs. -34±5%; SR -1.4±0.3s-1 vs. -2.6±0.6s-1, p<0.001. No differences were noted between the ASD group and controls. A significant negative correlation was noted between RV deformation and RV end diastolic volume (R=0.75) as well as RV length (R=0.76), p<0.001. When S and SR were corrected for RV size, the differences remained significant between groups. While all ASD patients and some patients after ToF repair had corrected deformation values comparable with controls, some ToF patients had very low corrected parameters, suggesting RV dyssfunction (figure).
Conclusion: Interpretation of RV deformation parameters should take into consideration loading conditions. S and SR imaging is sensitive in detecting a spectrum of changes in RV longitudinal function and a geometric correction for the values might be helpful identifying early signs of ventricular failure.
- © 2011 by American Heart Association, Inc.