Journal of Medical Diagnostic Methods
Open Access

Abstract

Use of Supine Bicycle Stress Echocardiography in Quantitating Right Ventricular Reserve and Exercise Capacity in Adults with Repaired Tetralogy of Fallot

Doreen DeFaria Yeh, Ameya Kulkarni, Karen G Ordovas, Robert W Yeh, Ami B Bhatt, Nelson B Schiller and Elyse Foster

Objective: This study aimed to examine exercise hemodynamic parameters and exercise capacity in adults with repaired tetralogy of Fallot (rTOF) obtained during supine bicycle echocardiography. Background: In addition to volumetric MRI parameters, exercise capacity in adults with rTOF is often used to determine timing for pulmonic valve replacement (PVR). Supine bicycle echocardiography is useful in measuring right ventricular (RV) hemodynamic parameters and quantifying exercise capacity and myocardial workload. Methods: Supine bicycle echocardiograms performed since 2002 were retrospectively reviewed among 33 adults with rTOF followed at a single adult congenital heart disease center. Echocardiographic and hemodynamic parameters were measured before and at peak exercise. Results: Mean age was 36 ± 12 yrs and severe pulmonic regurgitation (PR) was present in 56%. Mean exercise duration was 15 ± 5 minutes and peak double product was 24,461 ± 6779 units. There was no correlation between resting right ventricular volumetric measurements or tricuspid regurgitant velocity with exercise duration or peak double product. Symptomatic patients in this study had significantly shorter exercise times (17.1 ± 4 vs 12.1 ± 4 minutes, p=0.01) and a trend toward a significantly lower change in the mean pulmonary gradient with exercise (13 ± 8 mmHg vs. 7 ± 2 mmHg, p=0.07). After multivariable linear regression analysis adjusting for age, sex, and severity of PR, a 7 mmHg increase in the ΔPVGp was independently associated with an additional minute of exercise duration (p=0.01). Conclusion: Obtaining exercise right heart hemodynamics with supine bicycle echocardiography is feasible among adult patients with rTOF. Change in transpulmonary valvular gradient with exercise, may reflect RV contractile reserve and provide a physiologic correlate to symptoms and exercise capacity in patients with rTOF