Role of the renin-angiotensin system in the systemic vasoconstriction of chronic congestive heart failure.
In 15 patients with severe chronic left ventricular failure, plasma renin activity (PRA) ranged widely, from 0.2--39 ng/ml/hr. The level of PRA was unrelated to cardiac output (CO) or pulmonary artery wedge pressure (PWP), but was slightly negatively correlated with mean arterial pressure (MAP) (r = -0.45) and systemic vascular resistance (SVR) (r = -0.40). After infusion of the angiotensin converting enzyme inhibitor teprotide (SQ 20,881) PWP fell from 26.3 +/- 1.3 (SEM) to 20.3 +/- 1.4 mm Hg (P less than 0.001), CO rose from 3.94 +/- 0.23 to 4.75 +/- 0.31 l/min (P less than 0.001), MAP fell from 87.5 +/- 3.8 to 77.9 +/- 4.1 mm Hg (P less than 0.001) and SVR from 1619 +/- 148 to 1252 +/- 137 dyne-sec-cm-5 (P less than 0.001). The fall in MAP and in SVR was significantly correlated with control PRA (r = 0.68 and r = 0.58, respectively). When subjects were divided on the basis of control PRA the hemodynamic response to teprotide was greatest in the high renin group. PRA rose after teprotide (8.7 +/- 3.4 to 37.9 +/- 7.7 ng/ml/hr, P less than 0.05) but plasma norepinephrine fell (619.1 +/- 103.6 to 449.7 +/- 75.7, P less than 0.05). The renin-angiotensin system thus appears to have an important role in the elevated SVR in some patients with heart failure. Chronic inhibition of converting enzyme should be explored as a possible therapeutic approach.
D000328:Adult; D000368:Aged; D000804:Angiotensin II / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D011652:Pulmonary Circulation / Q000187:drug effects; D012083:Renin / Q000097:blood / Q000502:physiology*; D013722:Teprotide / Q000627:therapeutic use; D014655:Vascular Resistance / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects
D000804:Angiotensin II; D013722:Teprotide; D012083:Renin; D009638:Norepinephrine