The role of the left ventricle in atrial natriuretic peptide secretion in acute mitral regurgitation.

To examine the role of the ventricle in ANP secretion, the atrial natriuretic peptide (ANP) concentration in the plasma, left atrial tissue and left ventricular tissue were observed in a canine during the course of experimental reversible mitral regurgitation (MR). For reversible MR, a basket catheter was inserted into the left atrium via the pulmonary vein and fixed at the mitral valve. The regurgitation arose when the tip basket wire was extended and disappeared immediately when it was closed. Left atrial pressure (LAP), right atrial pressure (RAP) and pulmonary artery pressure (PAP) increased significantly during MR, and decreased to the normal level after recovery from MR. Plasma ANP concentration showed a reversible change in correlation with LAP and RAP in each canine studied. The ANP level in the atrial and ventricular tissue decreased during MR, and the low levels were maintained after recovery from MR. Both the left arterial and left ventricular tissue ANP levels showed the same changes in acute MR. Therefore, it was suggested that normal ventricles might play a role in ANP secretion in acute MR.