[The status of the renin-angiotensin-aldosterone system in patients in the early period following aortocoronary bypass surgery].

The state of renin-angiotensin-aldosterone system has been studied in 43 patients after aortocoronary bypass surgery. Renin activity, angiotensin II and aldosterone content have been studied, using radioimmunoassay, in comparison with hemodynamic findings and water-electrolyte balance parameters. The study was performed in patients with uncomplicated postoperative period and in patients with acute circulation disturbances just after surgery and 3, 6, 18 and 48 hours after surgical intervention. It has been shown that in uncomplicated postoperative period there is a 6-8-fold increase in plasma renin content and a 1.5-2-fold increase in aldosterone concentration. Despite an increase in aldosterone activity clinical signs of hyperaldosteronism became evident by the 18-48th hour postoperatively. A persistent increase in renin-angiotensin-aldosterone system activity in patients with acute circulation disturbances is considered as a compensatory body reaction directed at stabilization of the circulating blood volume and heart performance.