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Significance of coronary artery tone in patients with vasospastic angina
A Hoshio1, H Kotake, H Mashiba
1Department of Internal Medicine, Tottori University School of Medicine, Japan.
Insights
Patients with vasospastic angina exhibit abnormal coronary artery vasomotion, including increased basal tone and hypersensitivity to stimuli. This suggests a widespread disorder that may help predict spasm occurrence and location.
Area of Science:
- Cardiology
- Vascular Physiology
Background:
- Coronary artery spasm is a significant cause of ischemic heart disease.
- Understanding the underlying mechanisms of coronary artery spasm is crucial for diagnosis and treatment.
Purpose of the Study:
- To investigate the relationship between basal coronary artery diameter and the development of coronary artery spasm.
- To assess coronary vasoreactivity in patients with vasospastic angina compared to healthy individuals.
Main Methods:
- Coronary artery diameters (proximal, middle, distal segments, and left main trunk) were measured via angiography.
- Measurements were taken at baseline (control) and after ergonovine and nitrate administration.
- Coronary vasoreactivity was assessed by the percent change in diameter post-administration.
Main Results:
- Patients with vasospastic angina showed greater coronary artery responses to ergonovine and nitrate in spastic segments compared to non-spastic segments (p<0.05).
- Coronary arteries without spasm in vasospastic angina patients responded more significantly than those in healthy controls (p<0.01).
- Baseline coronary artery diameters were smaller in vasospastic angina patients than in controls.
Conclusions:
- Patients with vasospastic angina have a coronary vasomotion disorder characterized by increased basal tone and hypersensitivity to vasoconstrictive stimuli.
- This disorder affects the entire coronary artery tree, not just localized segments.
- Evaluating basal coronary artery tone may aid in predicting the occurrence and location of coronary artery spasm.
Abstract:
To investigate the relation between basal coronary artery diameter and development of coronary artery spasm, the diameters of the proximal, middle and distal segments of the three major coronary artery branches, together with that of the left main trunk, were measured on a control angiogram and after ergonovine and nitrate administration in 30 patients with vasospastic angina without significant organic stenosis, and in 35 patients without ischemic heart disease. The percent change in coronary diameter after ergonovine and nitrate administration compared with the control diameter was used as an index of coronary vasoreactivity. In patients with vasospastic angina, coronary artery responses to both ergonovine and nitrate were greater in the spastic segments than in the other segments (p less than 0.05), and those of the coronary arteries without spasm were greater than those of the coronary arteries in patients without ischemic heart disease (p less than 0.01). There were no significant differences between the coronary artery diameters in the two groups after nitrate administration, and the control diameters were less in patients with vasospastic angina than in patients without ischemic heart disease. These observations indicate that a coronary vasomotion disorder, which involves increased basal coronary artery tone and hypersensitivity to vasoconstrictive stimuli, not only at a localized segment but also in the entire coronary artery tree, is present in patients with vasospastic angina. Clinically, evaluation of basal coronary artery tone may be useful for predicting the occurrence and location of coronary artery spasm.