Door-to-needle: 30 minutes
This man has an ST-elevation myocardial infarction (STEMI) of the inferior wall, shown by ST elevation in leads II, III, and aVF, with 2 hours of chest pain. The hospital has no catheterization laboratory, and the nearest center that performs percutaneous coronary intervention (PCI) is 4 hours away, so timely PCI is not possible. When primary PCI cannot be done in time, a fibrinolytic such as alteplase or tenecteplase is started within 30 minutes of arrival, the door-to-needle goal.
Why time matters so much
In STEMI, a coronary artery is blocked by a thrombus, and heart muscle dies progressively the longer it goes without blood flow. Fibrinolytics dissolve the clot and are most effective when given early, ideally within the first few hours of symptom onset. Every minute saved preserves myocardium, reduces complications such as heart failure and dysrhythmias, and lowers mortality. The time targets are designed so that the whole system, from triage to treatment, works quickly and predictably.
| Time goal | What it measures |
|---|
| 10 minutes | Arrival to 12-lead ECG for chest pain |
| 30 minutes | Arrival to start of fibrinolytic (door-to-needle) |
| 90 minutes | First medical contact to device for primary PCI |
| 120 minutes | Device goal when a client must be transferred for PCI |
Why the other times are wrong
10 minutes is the goal for obtaining and interpreting the 12-lead ECG after arrival with chest pain. 90 minutes is the target from first medical contact to device for primary PCI. 120 minutes is the device goal when a client must be transferred to a PCI-capable center; when that cannot be met, as here with a 4-hour transfer, fibrinolysis is chosen instead. After fibrinolysis, the client is usually transferred to a PCI center for further care.
Watch out! Before giving a fibrinolytic, the nurse screens for contraindications such as active bleeding, recent major surgery or trauma, prior hemorrhagic stroke, and uncontrolled severe hypertension. During and after the infusion, monitor for bleeding and for reperfusion dysrhythmias. In inferior MI, also watch for bradycardia and right ventricular involvement, and avoid nitrates if right ventricular infarction is suspected.
Exam takeaway
Key point! Door-to-ECG 10 minutes, door-to-needle 30 minutes, first contact-to-device 90 minutes for primary PCI, and 120 minutes when transfer is needed. When PCI cannot be reached in time, give fibrinolysis within 30 minutes of arrival.