Reduced contractile reserve of the systemic right ventricle under Dobutamine stress is associated with increased brain natriuretic peptide levels in patients with complete transposition after atrial repair

AIMS: To compare B-type natriuretic peptide (BNP) levels with response of systemic right ventricular function to Dobutamine stress. METHODS AND RESULTS: Sixteen patients aged 25.6 +/- 3.7 years (eight each after Senning or Mustard repair of complete transposition) were studied. Transoesophageal imaging was performed in the catheterization laboratory under general anaesthesia before and at the end of a 10 min infusion of 5 microg/kg/min of Dobutamine. The BNP levels were measured at rest. Myocardial Doppler data were acquired before and at peak stress in a four-chamber view. The BNP (pg/mL) values of 67.3 +/- 47.5 (14-189) were elevated. There was no correlation between BNP and IVA, strain, or systolic and diastolic velocities at rest. Dobutamine stress led to a significant increase in IVA, s-velocity, and strain but no significant change in e-velocity. A correlation was found between increase in IVA under Dobutamine and BNP levels (r = 0.57, P < 0.02). CONCLUSION: Elevated BNP levels correlate with response of systolic right ventricular function assessed by IVA to Dobutamine stress.