Role of stress echocardiography in operated fallot: feasibility and detection of right ventricular response.

BACKGROUND: Patients with repaired tetralogy of Fallot often present residual hemodynamic abnormalities leading to right ventricular (RV) burden. Semisupine exercise echocardiography (Ex-Echo) is a validated method for diagnosis and prognosis in ischemic and valvular heart diseases and has potential for the evaluation of RV burden, pressure, and function. The aims of this study were to assess the effect of exercise on the right ventricle in adults with repaired tetralogy of Fallot and to identify factors associated with decreased RV function at peak exercise in an observational study.
METHODS: A total of 128 patients with repaired tetralogy of Fallot referred to an outpatient congenital heart disease unit were evaluated by Ex-Echo and conventional clinical and diagnostic examinations (i.e., electrocardiography, transthoracic echocardiography, cardiovascular magnetic resonance, cardiopulmonary exercise testing, and N-terminal pro-brain natriuretic peptide assay). The following Ex-Echo parameters were measured at rest and at peak exercise: tricuspid annular plane systolic excursion, RV pressure, and RV fractional area change (FAC).
RESULTS: Interpretable images for RV FAC analysis were obtained in 123 of 128 patients. In 91 of 128 with detectable tricuspid valve regurgitation, RV systolic pressure during exercise was evaluated. According to positive or negative RV FAC variation during exercise, 74 patients were respectively defined as "responders" on stress echocardiography and 49 as "nonresponders"; the median percentage change between rest and stress was 13.8% (interquartile range, 5.9% to 26.9%) in responders and -13.5% (interquartile range, -25.4% to -7.4%) in nonresponders. Systolic RV systolic pressure increased in a similar manner in the two groups (65 ± 36% in responders vs 59 ± 39% in nonresponders, P = .45). Tricuspid annular plane systolic excursion increased significantly during peak exercise in responders from 17.2 ± 3.4 mm at rest to 19.7 ± 4.3 mm (P < .0001) but did not in nonresponders (from 16.9 ± 4.7 to 18.1 ± 4.6 mm, P = .20). Left ventricular end-diastolic volume at rest and left ventricular ejection fraction < 50% were related to the lack of increased RV FAC on exercise.
CONCLUSIONS: Ex-Echo is feasible in patients with repaired tetralogy of Fallot and allows the integrated assessment of variation in RV systolic pressure, area, and function during exercise, which usefully complement more conventional indices of hemodynamic burden in these patients. Longitudinal follow-up is needed to better delineate the prognostic value of the results of Ex-Echo.