Plasma N-terminal pro-brain natriuretic peptide concentrations before and after pericardiocentesis in dogs with cardiac tamponade secondary to spontaneous pericardial effusion

Abstract Objective To determine if concentrations of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) are increased in dogs with cardiac tamponade and if there is a significant increase in plasma NT-proBNP after pericardiocentesis. Animals Ten client-owned dogs with spontaneous cardiac tamponade. Methods Prospective clinical study. Cardiac tamponade was suspected from physical examination and confirmed with echocardiography. Blood was collected and plasma NT-proBNP concentrations were measured before and 30–60 min following pericardiocentesis and resolution of cardiac tamponade. Within-subject changes in plasma NT-proBNP were compared by the Wilcoxon signed-rank test. Results The plasma NT-proBNP concentrations measured within the reference interval in seven of 10 dogs before pericardiocentesis and in six of 10 dogs following pericardiocentesis. Following pericardiocentesis, there was a statistically significant increase in median NT-proBNP concentration (733 pmol/L, range 250–3,297) compared with the values measured before (643 pmol/L, range 250–3,210, P = 0.004). The NT-proBNP concentration increased in 90% of the dogs following pericardiocentesis. Conclusions An upper reference limit of 900 pmol/L for plasma NT-proBNP is insensitive for the diagnosis of pericardial effusion and cardiac tamponade in dogs. Plasma NT-proBNP concentration commonly increases following pericardiocentesis, perhaps related to improved ventricular filling and stretch.