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The differential response in atrial natriuretic peptide release during exercise in patients with and without ischemic
1Department of Medicine, University of British Columbia, Vancouver, Canada.
Insights
Patients with ischemic heart disease show a greater increase in atrial natriuretic peptide after exercise. This finding suggests atrial natriuretic peptide may serve as a noninvasive marker for diagnosing exercise-induced ischemia.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Elevated cardiac filling pressure triggers atrial natriuretic peptide release.
- Ischemia during exercise can increase cardiac filling pressure before symptoms appear.
Purpose of the Study:
- To investigate the effect of exercise on circulating atrial natriuretic peptide (ANP) levels.
- To compare ANP response during exercise in patients with and without ischemic heart disease.
Main Methods:
- Treadmill exercise testing (Bruce protocol) was used.
- Heart rate, blood pressure, and atrial natriuretic peptide were measured.
- Two groups were studied: those with (Group 1) and without (Group 2) ischemic heart disease.
Main Results:
- Patients with ischemic heart disease exhibited significantly higher rates of rise in heart rate, blood pressure, and atrial natriuretic peptide.
- The rate of rise for ANP was 4.1 pg/ml/min in the ischemic group versus 1.4 pg/ml/min in the non-ischemic group.
Conclusions:
- Disproportionate elevation of atrial natriuretic peptide after exercise in patients with ischemia is likely due to increased cardiac filling pressure.
- Atrial natriuretic peptide may offer a noninvasive diagnostic method for 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.