%0 Journal Article %A P A Phillips %A J Sasadeus %A G P Hodsman %A J Horowitz %A A Saltups %A C I Johnston %T Plasma atrial natriuretic peptide in patients with acute myocardial infarction: effects of streptokinase. %D 1989 %R 10.1136/hrt.61.2.139 %J British Heart Journal %P 139-143 %V 61 %N 2 %X Plasma concentrations of immunoreactive atrial natriuretic peptide (mean (SEM] were measured in 135 patients admitted to two coronary care units with myocardial infarction, ischaemic chest pain, or non-ischaemic chest pain. Concentrations were significantly higher in patients with acute myocardial infarction not treated with systemic thrombolysis (60.4 (14.3) pg/ml) than in patients with non-ischaemic chest pain (21.1 (4.3) pg/ml). Patients with ischaemic chest pain had intermediate values (39.3 (7.1) pg/ml). Patients with acute myocardial infarction treated with intravenous streptokinase had normal concentrations of plasma atrial natriuretic peptide (20.2 (3.6) pg/mg), which were significantly lower than those in patients with myocardial infarction not given streptokinase. These changes could not be explained by factors such as age, pre-existing hypertension, renal dysfunction, or cardiac failure, nor treatment other than streptokinase. Raised plasma concentrations of atrial natriuretic peptide in acute myocardial infarction may be a homoeostatic response acting to reduce atrial pressures by natriuresis, diuresis, and venodilatation. The lower concentrations of atrial natriuretic peptide in patients with acute myocardial infarction treated with streptokinase may reflect a short term beneficial haemodynamic effect of streptokinase. %U https://heart.bmj.com/content/heartjnl/61/2/139.full.pdf