Effects of Volume and/or Pressure Overload Secondary to Congenital Heart Disease (Tetralogy of Fallot or Pulmonary Stenosis) on Right Ventricular Function Using Cardiovascular Magnetic Resonance and B-Type Natriuretic Peptide Levels

The aim of this study was to analyze the effect of pressure and/or volume overload on right ventricular (RV) function and brain natriuretic peptide (BNP) levels in patients with surgically corrected congenital heart disease. Forty-two consecutive patients aged 17 to 57 years (median 30) with congenital heart disease (32 with tetralogy of Fallot and 10 with pulmonary stenosis) were examined. The RV systolic pressure was estimated using Doppler echocardiography. Cardiovascular magnetic resonance imaging was used to obtain the RV volumes, ejection fraction (EF) and corrected EF (cEF). Plasma BNP levels were determined by immunoradiometric assay. Patients were categorized as having volume overload when pulmonary regurgitation was ≥10% and pressure overload when the RV systolic pressure was >40 mm Hg. Patients with RV volume overload had a lower RVEF compared with patients with pressure overload (p = 0.02) and lower left ventricular EF (p <0.001). BNP was higher in patients with volume overload than in patients with pressure overload (p = 0.002). BNP correlated with pulmonary regurgitation, RVEF, RV cEF, and left ventricular EF. In linear regression analysis, RV cEF was an independent predictor for BNP, after adjustment for age. Without the parameter of RV cEF in the regression model, pulmonary regurgitation and RVEF were independently associated with BNP level, after adjustment for age. In conclusion, patients with RV volume overload had higher BNP levels and lower RV function than patients with RV pressure overload. BNP levels were independently associated with the degree of RV volume overload and RV function.