Electrocardiographic Q-wave inconstancy in inferior wall myocardial infarction
| Autor: | David H. Spodick, Mei-Yu Chuang |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_specialty
Contraction (grammar) business.industry Myocardium Myocardial Infarction Inferior Wall Myocardial Infarction medicine.disease QT interval Muscle hypertrophy QRS complex Electrocardiography Acute myocarditis Internal medicine medicine Cardiology Inferior wall Humans Myocardial infarction Cardiology and Cardiovascular Medicine business |
| Zdroj: | The American journal of cardiology. 66(15) |
| ISSN: | 0002-9149 |
| Popis: | Abnormal Q waves fulfilling standard criteria are the hallmark of “Q-wave” myocardial infarction (MI).1–3 Although a surprisingly large number of enzyme-positive acute MIs do not produce Q waves,4,5 abnormal Q waves may seem to “resolve” or disappear. Disappearance of established abnormal Q waves may be explained by tissue changes during healing, scar contraction or hypertrophy of adjacent myocardium, vectorially opposite new MI reducing or canceling preexisting Q waves or recovery of stunned myocardium.6 In acute myocarditis mimicking acute MI, abnormal Q waves often disappear, presumably because of resolution of subnecrotic damage.7 In anterior wall MI, electrode placement can significantly change the QRS including Q waves, but not in inferior wall MI, diagnosed strictly from limb leads. We frequently observed Q waves with established criteria (≥0.04 second in lead aVF) to be present on one day and not on an adjacent day (Figures 1 and 2). Such inconstancy must be a confounding factor in evaluating electrocardiographic evidence. The relatively poor sensitivity of electrocardiographic criteria for inferior wall MI8 could be partly due to surprisingly frequent day to day fluctuation. |
| Databáze: | OpenAIRE |
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