Dobutamine stress echocardiography in the evaluation of cardiac haemodynamics after repair of tetralogy of Fallot in children: negative effects of pulmonary regurgitation

Objective - The aims were to evaluate right and left ventricular systolic function and pulmonary regurgitation (PR) at rest and during dobutamine stress echocardiography (DSE) and to assess relationships between PR and cardiac haemodynamics in late postoperative tetralogy of Fallot patients. Methods and results - Eighteen children (postoperative period 10.9 +/- 2.9 years) had heart rates, PR volumes and velocities, right ventricle (RV) volumes, ejection fraction, cardiac output and index measured at rest and during DSE. Left ventricular ejection fraction did not significantly increase and the RV volumes did not change significantly during DSE (p > 0.05). RV ejection fraction was significantly lower than that of the left ventricle at rest (p < 0.001), and patients failed to increase RV ejection fraction during DSE (p > 0.05). PR measurements increased significantly during DSE (p < 0.05). PR velocity correlated positively with RV end-diastolic volume both at rest and during DSE (p < 0.01). PR volume was inversely correlated with ejection fraction, cardiac output and index at rest and during DSE (p < 0.05). Conclusion - Latent dysfunction and impaired functional response to stress of both ventricles are detected by DSE. Although many postoperative patients are asymptomatic; assessment of postoperative haemodynamics by exercise or DSE will probably result in early detection of latent ventricular dysfunction.