The Differential Response in Atrial Natriuretic Peptide Release During Exercise in Patients with and Without Ischemic Heart Disease

Abstract

The elevation of cardiac filling pressure induces the release of atrial natriuretic peptide into the circulation. Ischemia during exercise in patients with coronary artery disease may manifest itself with elevation of cardiac filling pressure before the onset of electrocardiographic changes or chest pain. Thus, patients with ischemic heart disease might have an elevated circulating atrial natriuretic peptide after exercise. The present study investigated the effect of exercise on circulating atrial natriuretic peptide in patients with and without ischemic heart diseases. Group 1 was composed of five patients who had ischemic heart disease by clinical history, previous myocardial infarction, angina or angiographically proven coronary artery disease and positive electrocardiogram during exercise. Group 2 was composed of five patients without ischemic heart disease and negative electrocardiogram response. Heart rate, blood pressure, and atrial natriuretic peptide were measured during routine treadmill exercise testing using the Bruce protocol. Our results indicate that the rate of rise of heart rate (12.3 +/- 1.8 vs. 8.5 +/- 0.7 beats/min/min), blood pressure (7.1 +/- 1 vs. 4.2 +/- 0.8 mm Hg/minute), and atrial natriuretic peptide (4.1 +/- 1 vs. 1.4 +/- 0.3 pg/ml/min) was significantly elevated in patients with ischemic heart disease compared to the group 2 patients. These findings suggest that the disproportionate elevation of atrial natriuretic peptide after exercise in ischemia may be caused by elevation of cardiac filling pressure, which may provide a noninvasive method for the diagnosis of ischemic heart disease.