Diagnostic and prognostic importance of ST recording after an episode of unstable angina or non-Q-wave myocardial infarction

The diagnostic and prognostic value of ST recordings in unstable coronary artery disease were evaluated in 198 men below 70 years of age admitted to the coronary care unit because of chest pain due to myocardial ischaemia but without the development of Q-wave infarction. The ST recordings were performed for 24 h in bed in the CCU (n = 75) between 6and66 hours after the last episode of pain, before discharge during ambulation in hospital 4–6 days after admission (n = 198), and ambulatory out of hospital 1 month later (n = 109). The long-term ECG was registered from bipolar leads corresponding to V2 and V5 using two-channel FM-recorders. Significant ST episodes were defined as ST segment deviation ≥0.1 mV from baseline and lasting for at least 1 min. During the recordings 85–90% of the patients were treated with beta blockers and 27–41% also with calcium channel blockers. In the CCU recordings, ST depression occurred in 23% of the patients, 21% had asymptomatic and 7% symptomatic episodes. Before discharge the ST recordings showed ST depression in 18% of the patients, 16% asvmptomatic and 7% symptomatic. Ambulatory monitoring after 1 month showed a higher occurrence of ST depressions-33% (P