Haemodynamic effects of pharmacological doses of secretin in patients with impaired left ventricular function.

The haemodynamic effects of secretin 4 CU/kg.h was studied in seven patients with impaired left ventricular function. Cardiac output (P less than 0.01) and stroke volume (P less than 0.05) increased persistently during the infusion period, whereas the total systemic resistance fell (P less than 0.01). Heart rate increased slightly (P less than 0.01). The systemic arterial pressure was unchanged except for a small, transient reduction at the onset of the infusion (P less than 0.01). The pulmonary capillary wedge pressure, the pulmonary artery pressure and the pulmonary arteriolar resistance were unaltered. In patients with depressed cardiac function, pharmacological doses of secretin increased left ventricular performance by means of arteriolar dilation and a positive inotropic effect is also suggested.