Initial diagnostic assessment: patients presenting with symptoms of a suspected acute coronary syndrome
| Initial laboratory assessment | Clinical diagnosis | Diagnostic category |
| ECG shows persistent ST segment elevation | ST segment elevation myocardial infarction | Exit this guideline |
|
ECG normal or ischaemic changes (no persistent ECG ST-segment elevation) Raised CK-MB enzyme (more than twice the upper limit of the reference range)and cardiac troponin positive | Non-Q wave myocardial infarction | Confirmed acute coronary syndrome |
| ECG shows ischaemic changes (no persistent ECG ST-segment elevation)and/or cardiac troponin positive CK-MB enzyme not raised | Confirmed unstable angina | Confirmed acute coronary syndrome |
|
ECG normal Cardiac troponin normal CK-MB enzyme not raised | Suspected unstable angina | Unconfirmed acute coronary syndrome |