Supplemental Data Figure 1: Reverse phase-HPLC of atrial extract from subject 3. Each fraction was assayed with three separate immunoassays: N-terminal assay – solid dark grey line and triangles, commercial assay – heavy black line and closed circles, and C-terminal assay – light grey line and open circles. The elution positions of BNP(1-32) and BNP(3-32) standards are shown by the large and small arrows respectively, and that of proBNP by the square bracket. Major peaks have been numbered to correspond with those in the text.