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Relationship between the coronary diameter and occurrence of vasospastic angina in patients with normal coronary
T Kurimoto1, M Karakawa, M Baden
12nd Department of Internal Medicine, Kansai Medical University, Oska, Japan.
Insights
Patients with angina pectoris and normal coronary arteries exhibit increased basal tone. Vasospastic angina requires local arterial abnormalities, not just general responses, to interventions.
Area of Science:
- Cardiology
- Physiology
Background:
- Patients with angina pectoris often present with normal coronary arteries on angiography.
- The underlying mechanisms for chest pain in these patients are not fully understood.
Purpose of the Study:
- To investigate coronary artery dynamics in patients with and without angina pectoris but with normal coronary arteries.
- To differentiate between general coronary tone and localized vasospasm.
Main Methods:
- Coronary artery diameters were measured in 30 patients without angina (Group 1) and 15 with angina (Group 2).
- Measurements were taken during rest, exercise, and after ergonovine and isosorbide dinitrate administration.
- Coronary vasospasm was assessed based on diameter changes.
Main Results:
- Group 2 patients showed significantly smaller coronary artery diameters than Group 1 at baseline, during exercise, and after ergonovine.
- Isosorbide dinitrate normalized diameters in both groups.
- Patients developing vasospastic angina exhibited local vasoconstriction or severe diffuse narrowing (<45%).
Conclusions:
- Angina pectoris in patients with normal coronary arteries is associated with increased coronary arterial basal tone.
- Vasospastic angina is not solely caused by exaggerated basal tone but requires a localized abnormal response to interventions.
Abstract:
Coronary artery diameters were measured after various interventions in 30 patients without angina pectoris (group 1) and in 15 with angina pectoris (group 2: rest, or rest and effort angina) who had normal coronary arteries. The coronary artery diameters were significantly smaller in many coronary segments in group 2 than in group 1 during a control state, after exercise and ergonovine, but became nearly identical after isosorbide dinitrate in both groups. Patients in group 1 had diffuse narrowing but no focal vasoconstriction after ergonovine and all the segments had a diameter of more than 50% of that after isosorbide dinitrate. The change of coronary artery diameter in group 2 patients who had no vasospasm by ergonovine was the same as that in group 1. Patients in whom vasospastic angina was induced had local vasoconstriction or severe diffuse narrowing (less than 45%). These results indicate that angina pectoris patients with normal coronary arteries had an acceleration of coronary arterial basal tone, but vasospastic angina pectoris was not induced just by the general response of the coronary artery to various interventions in addition to the accentuated basal tone. For vasospastic angina to occur, local abnormal response to various interventions must be present.