Pulmonary Embolism (PE)
A pulmonary embolism is a blood clot that travels to the lungs. It can cause chest pain, breathlessness, ECG changes and a rise in troponin (a heart-injury blood test), which is why it sometimes looks like a heart attack. But the problem is in the lungs/right side of the heart, not a blocked coronary artery.
1) What is PE & why does it mimic a heart attack?
A clot (often from a deep vein thrombosis in the leg) lodges in the lung arteries. Pressure in the lung circulation rises and strains the right ventricle (RV). This strain can cause chest discomfort, ECG changes and a troponin rise—features that overlap with a heart attack even though the heart arteries are usually not blocked.
Typical symptoms
- Pleuritic chest pain (worse on breathing in) or pressure
- Breathlessness; fast breathing; cough ± blood-streaked sputum
- Fast heartbeat, light-headedness or fainting
- Calf pain/swelling (possible DVT source)
Why it looks like MI
- Troponin elevation: micro-injury from RV strain
- ECG changes: fast rate, right-heart strain patterns, ST–T changes
- Chest pain/anxiety: overlaps with heart-attack symptoms
If you’re severely unwell (worsening breathlessness, chest pain, fainting), call 999 or go to the Emergency Department.
2) Tests that distinguish PE from a heart attack
First-line tests
- 12-lead ECG: fast rate; right-sided strain signs can appear
- High-sensitivity troponin: may be raised from RV strain
- D-dimer: useful when clinical probability is low/intermediate
- Oxygen levels and, if needed, blood gases
Imaging
- CT pulmonary angiography (CTPA): main test to confirm/exclude PE
- Leg Doppler ultrasound: looks for DVT if CTPA isn’t possible
- Echocardiography: checks RV size/function and pressure load
Cardiac testing
- Coronary angiography if a heart attack still suspected
- Cardiac MRI (CMR) in selected cases to clarify injury pattern
Clinicians often use scoring tools (e.g., Wells/Geneva) to judge likelihood first, then D-dimer and/or CTPA to confirm the diagnosis.
3) Treatment & acute management
Core treatment
- Anticoagulation: prevents the clot getting bigger and stops new clots
- Thrombolysis: “clot-buster” medicine for high-risk PE (shock/very low BP)
- Oxygen and careful fluids to support the right side of the heart
- Pain and anxiety control
Specialist options
- Catheter-directed therapy: locally break up or dissolve clot
- IVC filter: rarely, if blood thinners can’t be used
- Input from a PE response team (PERT) for complex cases
- How long on blood thinners? Commonly 3–6 months for a first event; longer if unprovoked or higher risk—your team individualises this.
- Search for triggers (recent surgery, immobility, hormones, cancer, clotting tendency) to guide duration and prevention.
- Mobilise early and work on risk-factor changes (weight, activity, smoking cessation).
4) Recovery, follow-up & outlook
Many people improve over weeks to months, though tiredness and breathlessness can linger for a while. A small number develop chronic thromboembolic pulmonary hypertension (CTEPH); specialist assessment and treatment are available. Follow-up often checks symptoms, exercise tolerance and anticoagulation safety.
What helps recovery?
- Prompt diagnosis and the right treatment
- Completing the full anticoagulation course
- Addressing risk factors and triggers
- Gradual, supported return to activity
When to seek help
- New/worsening breathlessness, chest pain or fainting
- New leg swelling/pain (possible DVT)
- Bleeding or easy bruising while on blood thinners
5) Where does PE fit within “mimics”?
PE is part of Group E: Mimics of Myocardial Infarction. It can raise troponin and alter the ECG, but the underlying problem is a lung artery clot causing right-sided heart strain, not a blocked heart artery. Recognising PE quickly prevents unnecessary stents and enables life-saving anticoagulation.
6) Knowledge gaps & research priorities
- Best ways to triage chest pain with raised troponin to avoid missed PE
- Who needs closer cardiac follow-up after troponin-positive PE?
- Optimal rehabilitation and exercise after PE
- Early markers predicting CTEPH and who to screen
Explore studies in our research hub and connect with others in the community forum. If your presentation overlapped with a suspected heart attack (MINOCA), you may also find the pages on IMPS and Takotsubo helpful.