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[Silent myocardial ischemia in unstable angina and acute myocardial infarction. Prospective clinical study]
E C Morales1, J Verdejo París, E Frutos Rangel
1Instituto Nacional de Cardiología Ignacio Chávez, México, D.F.
Insights
Silent myocardial ischemia is common in unstable angina (86%) and acute myocardial infarction (66%), with most episodes being silent. This suggests factors beyond coronary artery lesions contribute to ischemia.
Area of Science:
- Cardiology
- Ischemic Heart Disease
- Diagnostic Electrocardiography
Context:
- Unstable angina and acute myocardial infarction are critical cardiovascular conditions.
- Silent myocardial ischemia, often undetected, poses significant clinical challenges.
- Understanding its prevalence is crucial for risk stratification and management.
Purpose:
- To determine the prevalence and characteristics of silent myocardial ischemia.
- To investigate the correlation between silent ischemia and coronary artery lesions.
- To explore contributing factors beyond anatomical blockages.
Summary:
- A study of 30 patients (15 unstable angina, 15 acute myocardial infarction) utilized 24-hour ECG monitoring and coronary angiography.
- Silent ischemic ST changes were detected in 90% of ischemic episodes in unstable angina and 75% in acute myocardial infarction.
- No correlation was found between silent ischemia and coronary artery lesion severity (Gensini score) or angiographic morphology.
Impact:
- Silent myocardial ischemia is highly prevalent in acute coronary syndromes, often asymptomatic.
- Ischemia is influenced by multiple factors including vasoconstriction and endothelial dysfunction, not solely coronary anatomy.
- Findings highlight the need for comprehensive assessment beyond traditional markers in managing ischemic heart disease.
Abstract:
To establish the prevalence and characteristics of silent myocardial ischemia in patients with unstable angina and acute myocardial infarction and its possible correlation with coronary artery lesions; two groups patients were studied, fifteen with unstable angina and fifteen with acute myocardial infarction. In all patients a continuous 24 hours ECG recording was made with a solid state microprocessor for ST variation analysis, and all underwent coronary arteriography and ventriculography, the severity of coronary heart disease was determined by Gensini scoring system and the coronary angiography morphology was studied. In 86% patients with unstable angina ischemic ST changes were found, 90% of these episodes were silent. There were 66% of the patients with acute myocardial infarction and ST ischemic changes of these 75% were silent. There was no correlation with the ischemic myocardium score index, nor with the angiographic morphology or the heart rate. Therefore it can be said that myocardial ischemia is a result not only of anatomic factors but of many others such as vasoconstriction, endothelial, myocardial, systemic and hemorheological alterations.