Impact of pulmonary regurgitation and right ventricular dysfunction on oxygen uptake recovery kinetics in repaired tetralogy of Fallot.

BACKGROUND

Patients with repaired tetralogy of Fallot (ToF) featuring severe pulmonary regurgitation (PR) and/or right ventricular (RV) dysfunction have reduced exercise tolerance.

AIMS: To assess the impact of PR and of RV function on the ability to recover from exercise in ToF patients.

METHODS

61 consecutive patients aged 23.1+/-12.1 years underwent maximal cardiopulmonary exercise test (CPX), transthoracic echocardiography and magnetic resonance imaging. This data was compared to those of 153 matched healthy subjects.

RESULTS

19 patients (31%) had severe PR. RV dysfunction was noted in 19 patients (31%). Nine patients (15%) had both severe PR and RV dysfunction. Patients had lower peak oxygen uptake (VO2), VO2 slope, carbon dioxide production (VCO2) slope and O2 pulse slope (p < 0.0001), especially those with severe PR and RV dysfunction (p < 0.0001). Heart rate slope was similar between groups. No patient with severe PR and RV dysfunction had a predicted peak VO2 > 40%. CPX had a high sensitivity and specificity to identify patients with severe PR and RV dysfunction.

CONCLUSIONS

In ToF patients, severe PR and RV dysfunction lead to delayed recovery from exercise. CPX can identify patients with severe PR and RV dysfunction and may be useful to guide the pulmonary valve replacement decision-making process.