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Coronary arterial spasm in ischemic heart disease and its pathogenesis. A review
Insights
Coronary arterial spasm is a key factor in various angina types and heart attacks, often occurring at rest in the early morning. Calcium channel blockers like diltiazem and nifedipine effectively prevent spasm, while beta-blockers may worsen it.
Area of Science:
- Cardiology
- Vascular Medicine
- Pharmacology
Background:
- Coronary arterial spasm is implicated in variant angina, resting angina, exertional angina, and acute myocardial infarction.
- Spasm typically occurs at rest, especially from midnight to early morning, coinciding with increased coronary artery tone.
- Factors like exercise, pharmacological agents, and stress can induce coronary arterial spasm, particularly in the morning.
Purpose of the Study:
- To investigate the role of coronary arterial spasm in different cardiac conditions.
- To understand the temporal patterns and triggers of coronary arterial spasm.
- To evaluate the efficacy of various pharmacological agents in preventing and treating coronary arterial spasm.
Main Methods:
- Review of literature on coronary arterial spasm and its triggers.
- Analysis of the effects of different drug classes (calcium channel blockers, alpha-blockers, beta-blockers) on coronary arterial spasm.
- Observation of the effectiveness of nitroglycerin in acute spasm attacks.
Main Results:
- Diltiazem and nifedipine (calcium-blocking agents) successfully prevented spasm in nearly all patients.
- Phentolamine (alpha-blocking agent) suppressed spasm in 81% of patients.
- Propranolol (beta-blocking agent) was ineffective in 82% of patients and worsened spasm in 41%.
Conclusions:
- Coronary arterial spasm is a significant contributor to various ischemic heart diseases.
- Calcium channel blockers are highly effective in preventing exercise- and pharmacologically induced coronary arterial spasm.
- Beta-blockers may exacerbate coronary arterial spasm and should be used cautiously.
Abstract:
Coronary arterial spasm plays an important role iun the production not only of variant angina but, also, of resting angina other than variant angina, of some exertional angina, and of some acute myocardial infarction. Coronary arterial spasm is most likely to occur at rest, particularly from midnight to early morning, and is usually not provoked by exercise in the daytime. This is related to the fact that the tone of coronary artery is increased from midnight to early morning, whereas it is decreased in the daytime after physical activities. Coronary arterial spasm can be induced by exercise, cold pressor test, hyperventilation, Valsalva maneuver, and the administration of pharmacological agents such as sympathomimetic agents (epinephrine, norepinephrine, etc.), beta-blocking agents (propranolol, etc.), parasympathomimetic agents (methacholine, pilocarpine, etc.), ergot alkaloids (ergonovine, ergotamine, etc.), alcohol, and others, particularly in the morning when spontaneous coronary arterial spasm is most likely to occur. Diltiazem and nifedipine, calcium-blocking agents, prevent coronary arterial spasm induced by these procedures in almost all patients. Phentolamine, an alpha-blocking agent, also suppresses coronary arterial spasm induced by these procedures in 81% of the patients. On the other hand, propranolol, a beta-blocking agent, is not only ineffective in suppressing coronary arterial spasm in 82% of the patients, but aggravates coronary arterial spasm in 41% of the patients. The acute attack of coronary arterial spasm can be promptly relieved by the administration of nitroglycerin.