Comparison based on age of baseline electrocardiographic abnormalities in non-Q-wave myocardial infarction

OBJECTIVE: To compare the incidence of electrocardiographic abnormalities between older (age ≥ 70 years) and younger patients presenting with acute non-Q-wave myocardial infarction. DESIGN: Retrospective review of qualifying electrocardiograms in 918 patients enrolled in the multicenter Veterans Affairs Non-Q-Wave Infarction Strategies In-Hospital (VANQWISH) study. SETTING: Seventeen Department of Veterans Affairs medical centers. PARTICIPANTS: A total of 918 patients (224 ≥ 70 years old) with acute non- Q-wave myocardial infarction. MEASUREMENTS: Comparison of electrocardiograms in patients aged ≥70 years and younger patients for presence of left ventriculary hypertrophy, widened QRS complex, ST and T wave abnormalities, rhythm other than sinus, heart rate ≥80 beats/minute, and location of acute non-Q-wave myocardial infarction. RESULTS: Left ventricular hypertrophy and ST depression ≥1 mm were significantly more frequent in older than in younger patients. CONCLUSIONS: Older patients presenting with non-Q-wave myocardial infarction have a greater incidence of left ventricular hypertrophy and ST depression on their electrocardiograms than younger patients. Both of these electrocardiographic findings have previously been associated with increased risk of death and recurrent myocardial infarction and may help account for the worse prognosis of non-Q-wave myocardial infarction in older patients.