Cardiac stress test
Also known as: exercise ECG, exercise tolerance test, treadmill test, cardiac stress test
The heart is made to work hard, by treadmill or bicycle exercise or by a drug that mimics exercise, while its electrical activity, images or blood flow are recorded. A narrowed coronary artery that copes at rest fails under load, revealing itself as ECG change, a segment of muscle that stops moving, or a patch that does not take up tracer.
- Abbreviations
- ETT
- Kind
- Physiological or functional test
- Categories
- Cardiovascular
- Specimen
- No specimen
- Method
- Electrophysiological recording
What it measures
| Measure | What it tells you |
|---|---|
| ECG changes with exercise | ST depression, arrhythmia or a fall in blood pressure signal ischaemia. |
| Exercise capacity | Minutes achieved and heart rate reached; a strong predictor of prognosis in itself. |
| Stress echo wall motion | A segment that moves at rest but not under stress marks a significant narrowing. |
| Perfusion (nuclear or MRI) | Reduced tracer uptake under stress that recovers at rest = reversible ischaemia; fixed defect = scar. |
Why it is ordered
- Chest pain on exertion with an intermediate probability of coronary disease
- Assessing how much a known narrowing matters
- After a heart attack or angioplasty, before cardiac rehabilitation
- Exercise-induced palpitations or blackouts
How it is done
Electrodes and blood pressure cuff on; the treadmill speeds up every three minutes until target heart rate, symptoms or ECG change. Imaging versions add ultrasound or a radioactive tracer.
Preparation. Light meal only; comfortable shoes; some heart drugs (beta blockers) are paused on instruction.
Reading the result
| Finding | Usual meaning |
|---|---|
| Marked ST depression early in exercise | High-risk coronary disease; proceed to angiography |
| Good exercise capacity with no changes | Low risk; significant disease unlikely |
| Reversible perfusion defect | Viable muscle with restricted supply, likely to benefit from revascularisation |
Reference ranges vary by laboratory, method, age, sex and clinical context; a result is read against the person, not a table.
Limitations
Exercise ECG alone misses a fifth of disease and gives false positives, especially in women and with abnormal resting ECGs; CT coronary angiography is now the first test in many guidelines.
Catalogued concepts this page covers
Concepts of the master test taxonomy that resolve to this page; each links to its category.