Determining the Cause

Chief Complain: Chest Pain

Unstable Patient

Pivotal Assessments (One after the other)	Finding
EKG	ST Segment Elevation Non ST Segment Elevation Indeterminate Left bundle branch block	Presence of Q waves T-wave inversion Ventricular Tachycardia Ventricular Tachycardia Ventricular Fibrillation Normal
Portable Chest X-Ray	Pneumothorax Pneumonia Pleural Effusion	Aortic Dissection 1 2 . [ Intramural hematoma (IMH) - Bleeding within the aortic wall without an intimal tear 1 . Penetrating atherosclerotic ulcer (PAU) - An ulceration in an atherosclerotic plaque that penetrates the internal elastic lamina .
D-Dimer*	Elevated, Greater than .05	< .05

Pivotal Assessments (One after the other)

Finding

EKG

ST Segment Elevation

Non ST Segment Elevation

Indeterminate

Left bundle branch block

Presence of Q waves

T-wave inversion

Ventricular Tachycardia

Ventricular Fibrillation

Normal

Portable Chest X-Ray

Pneumothorax

Pneumonia

Pleural Effusion

Aortic Dissection

1

2
.
[ Intramural hematoma (IMH) - Bleeding within the aortic wall without an intimal tear
1

.
Penetrating atherosclerotic ulcer (PAU) - An ulceration in an atherosclerotic plaque that penetrates the internal elastic lamina

.

D-Dimer*

Elevated, Greater than .05

< .05

* D-Dimer Reference

++++++++++++++

Yes, coronary angiography may be indicated even before troponin results are available if the electrocardiogram (ECG) shows certain high-risk changes consistent with ST-elevation myocardial infarction (STEMI) or life-threatening ischemia.

✅ When to Proceed with Urgent Angiography Before Troponin:

🚨 Immediate angiography (and likely PCI) is indicated when:

ECG shows ST-elevation MI (STEMI):
- ST elevation ≥1 mm in ≥2 contiguous leads
- New or presumed new left bundle branch block (LBBB)
- Posterior MI (ST depression in V1–V3 with tall R waves)
Patient is in cardiogenic shock, ongoing chest pain, or has ventricular arrhythmias.
Very high clinical suspicion of MI even without biomarker confirmation:
- e.g., classic crushing chest pain, diaphoresis, hypotension, and high-risk history

🕒 Why not wait for troponin?

STEMI is a clinical diagnosis based on ECG, not troponin.
Waiting for troponin delays life-saving reperfusion, which must be done within 90 minutes ("door-to-balloon time").
Troponins confirm diagnosis later but are not needed to initiate emergent PCI in STEMI.

📌 Bottom Line:

Scenario	Angiography Timing
STEMI on ECG	Immediate (don’t wait for troponin)
NSTEMI or unstable angina	After troponin and risk stratification
No ischemic ECG changes	Wait for troponin and clinical evaluation

Would you like a decision algorithm for STEMI vs NSTEMI management?