Adults with Ebstein's anomaly--Cardiopulmonary exercise testing and BNP levels exercise capacity and BNP in adults with Ebstein's anomaly.
ABSTRACT Ebstein's anomaly is defined as the significant apical displacement of the part of the tricuspid valve causing significant tricuspid regurgitation and reduction of the functional right ventricle. The aim of the study was to evaluate exercise capacity with cardiopulmonary stress testing and to determine plasma BNP levels in adults with Ebstein's anomaly, and to establish their relation with echocardiogaphic grading of the lesion severity.
Study group consisted of 21 patients (16 males, aged 40.3+/-11.5 years). The control group: 19 healthy individuals (13 males, aged mean 39.9+/-9.3 years). On echocardiography the grade of the lesion severity was calculated (EGE) and used to define the following four groups: I < 0.5, II: 0.5-0.9, III: 1.0-1.49, IV > 1.5. The forced vital capacity (FVC), first second forced expiratory volume (FEV1), peak oxygen uptake (peak VO2), and VE/VCO2 slope were assessed with cardiopulmonary stress test and plasma BNP levels measured with radioimmunometric assay.
In the studied group VO2 was lower than in control (21.9+/-5.4 vs. 33.6+/-8.3 mL/kg/min [p = 0.00001]), VE/VCO2 slope was higher in Ebstein's group (40.1+/-8.1, p = 0.00001). BNP levels were higher in the Ebstein group then in controls (35.9+/-25.0 vs. 17.2+/-9.9 pg/mL [p = 0.0002]) and did not differ significantly between EGE groups. PeakVO2 of 24.5+/-3.9 in patients from II EGE group were higher than in patients from EGE groups: III (17.2+/-5.2 p = 0.007) and IV (22.9+/-4.7 p = 0.05).
Exercise capacity of adults with Ebstein's anomaly is significantly reduced and plasma BNP levels are higher compared to healthy individuals. Exercise capacity in patients with Ebstein's anomaly becomes gradually lower alongside the EGE severity; however, BNP levels do not correlate significantly with this parameter.