Unstable angina, NSTEMI, STEMI: what the marker adds to the twelve-lead
A marker rise-and-fall curve across hours from onset: a flat line for unstable angina, a troponin curve rising by about three hours and falling over seven to fourteen days, and a dashed CK-MB reinfarction curve, with a pointer chip in place of a y-axis scale.
| UNSTABLE ANGINA | NSTEMI | STEMI | |
|---|---|---|---|
| Pain pattern | At rest, new, or newly worse; not relieved by rest | At rest or newly worse; not relieved by rest | At rest or newly worse; not relieved by rest |
| Twelve-lead | Normal, or ST depression, or T wave inversion | ST depression or T wave inversion, no persistent elevation | ST elevation in two contiguous leads with reciprocal depression |
| Marker behavior | No rise and fall | Rise and fall present | Rise and fall present, but not waited for |
| What decides it | The clinical story | The marker | The twelve-lead alone |
| Time target | Twelve-lead obtained and read within ten minutes of arrival | Twelve-lead within ten minutes; serial tracings if pain returns | Twelve-lead within ten minutes; reperfusion clock starts at once |
| First nursing actions | Position of comfort, monitor, access, twelve-lead first | Same, plus serial twelve-leads and continuous rhythm watch | Same, plus activate the reperfusion pathway and stay at the bedside |
| Medication gates | Pressure checked before every nitrate dose | Pressure checked before every dose; antiplatelet gates checked | Pressure and wall involvement checked before any nitrate |
First nursing actions, spelled out. Sit the patient up unless the pressure forbids it. Give oxygen only when the saturation is low, because routine oxygen in a normally saturated patient is not benign. Place continuous cardiac monitoring, obtain intravenous access, and get the twelve-lead before anything else that is not an assessment. Stay in the room. Serial pain scores and serial pressures are data the next decision depends on.
Reperfusion timing, STEMI column only. At a facility that performs percutaneous coronary intervention, the target from first medical contact to device is within ninety minutes. When the patient must be transferred, the target is within one hundred twenty minutes. When neither can be met, a fibrinolytic is given within thirty minutes of arrival if there is no contraindication.
Medication gates.
- Blood pressure is checked before every nitroglycerin dose, and the dose is held for a systolic below the parameter written in the order.
- No nitrate if a phosphodiesterase-5 inhibitor was taken recently: within twenty-four hours for sildenafil or vardenafil, within forty-eight hours for tadalafil.
- Aspirin is chewed, not swallowed whole, unless it is contraindicated.
- A beta blocker is held for the heart rate and pressure parameters written in the order, and for signs of new heart failure.
Margin notethey always ask what you do while you wait for the troponin.
Memory hookTHE MARKER TELLS YOU LATE. THE TWELVE-LEAD TELLS YOU NOW. Registered as B8-LATE-NOW.
Marker values and thresholds live at → BOOK 07 · P4. Antiplatelet and anticoagulant class behavior lives at → BOOK 05 · P3.
Takeawaya normal first troponin never delays the twelve-lead, the monitor, or the call.