Comparisons between different syndromes of heart attack--a multivariate analysis.

A register of acute coronary events in Auckland, New Zealand enabled characterization of cases of the following different coronary syndromes: definite myocardial infarction (MI) (divided to Type I with typical ECG findings and Type II with new symmetrical T wave inversion only), nonhypotensive definite infarction with and without ventricular fibrillation, possible myocardial infarction and sudden death. Comparisons between these syndromes were analyzed. ECG type II (as compared to ECG type I) definite infarction was a more chronic, repeated syndrome, with more myocardial fibrosis in fatal cases, and more previous prolonged anginal pain without documented infarction. Cases of possible (as compared to definite) myocardial infarction were also more likely to report previous prolonged aningal pain, to use beta blockers, furosemide and less likely to die within 30 days. They consumed significantly more alcohol and were more likely to be female, than cases of definite infarction. Patients with nonhypotensive definite infarction complicated by ventricular fibrillation had higher acute phase pulse rates and more pallor and sweating than similar patients not experiencing ventricular fibrillation. Some possible explanations for the above findings were discussed.