Transient myocardial ischemia stimulates atrial natriuretic factor release.

Atrial natriuretic factor release during transient myocardial ischemia was investigated in 29 patients with coronary artery disease and symptoms of angina (Canadian Cardiovascular Association classes II-III). Eleven patients (group I) underwent single-vessel percutaneous transluminal coronary angioplasty. Repeat determinations of mean pulmonary artery wedge pressure and blood sampling from pulmonary artery for atrial natriuretic factor measurements were performed at baseline, and at 2, 5, and 15 minutes after percutaneous transluminal coronary angioplasty was begun. Baseline atrial natriuretic factor levels (34.6 +/- 4.5 pg/ml) rose to 56.3 +/- 7.3 pg/ml (p = 0.02) and decreased at 5 minutes (43.7 +/- 5.7 pg/ml, not significant) and 15 minutes (35.3 +/- 4.4 pg/ml, not significant). Changes in atrial natriuretic factor concentrations were significantly correlated with those in mean pulmonary artery wedge pressure (2 minutes: r = 0.69, p = 0.02; 5 minutes: r = 0.90, p less than 0.001). In group II (n = 10) the increase in atrial natriuretic factor after dye load occurred later (baseline: 25.8 +/- 2.1; 60 minutes: 40.6 +/- 2.6 pg/ml; p = 0.005) than that observed in group I after percutaneous transluminal coronary angioplasty. In group III, atrial natriuretic factor during angina rose as early (baseline 11.3 +/- 1.3; 5 minutes: 20 +/- 2.3 pg/ml; p = 0.006) as after percutaneous transluminal coronary angioplasty. Results indicate that transient myocardial ischemia stimulates atrial natriuretic factor release, probably through changes in cardiac function.