🏃 Duke Treadmill Score Calculator
Evaluate coronary artery disease (CAD) risk using the Duke Treadmill Score. This weighted index uses exercise time, ST-segment deviation, and angina to provide diagnostic and prognostic information.
📊 Duke Treadmill Score Results
Coronary Artery Disease
Coronary artery disease (CAD) is the most common type of heart disease. It is caused by plaque buildup in the walls of the arteries that supply blood to the heart, successively narrowing them and limiting blood flow.
The symptoms and complications of CAD include:
- Angina — chest pain and discomfort
- Heart attack — weakness, nausea, cold sweat, shortness of breath
- Heart failure — dyspnea, fatigue, swelling in the legs, rapid heartbeat
Risk factors include being overweight, physical inactivity, unhealthy diet, smoking, and family history of CAD. An exercise stress test is one method to diagnose CAD, and the Duke Treadmill Score helps evaluate the results.
Duke Treadmill Score
The Duke Treadmill Score is a weighted index using treadmill exercise time (per the standard Bruce protocol), maximum net ST-segment deviation, and exercise-induced angina. It was developed to provide diagnostic and prognostic information for patients with suspected coronary heart disease.
The typical observed range is from −25 (highest risk) to +15 (lowest risk).
Where:
- Exercise — duration of exercise in minutes
- ST-segment deviation — maximal net ST change in any lead except aVR (in mm)
- TAI — Treadmill Angina Index: 0 = no angina, 1 = typical angina, 2 = exercise stopped because of angina
Interpretation
Patients are categorized into three risk groups:
| Score | Risk Group | 4-Year Survival |
|---|---|---|
| ≥ 5 | Low Risk | 99% |
| −10 to +4 | Medium Risk | 95% |
| < −10 | High Risk | 79% |
Practical Example
A patient named Susan took a Duke treadmill test. She exercised for 8 minutes, had no angina (TAI = 0), and her maximal net ST-segment deviation was 0.6 mm.
- Duke = 8 − 5 × 0.6 − 4 × 0
- Duke = 8 − 3 − 0
- Duke = 5
Interpretation: Susan falls into the low-risk category with a 4-year survival of approximately 99%.
FAQs
What is the Bruce protocol?
The Bruce protocol is a standardized treadmill exercise test that increases speed and incline every 3 minutes through several stages. It is the most commonly used protocol for evaluating cardiac function and exercise capacity.
What does the ST segment tell us?
The ST segment on an ECG represents the period between ventricular depolarization and repolarization. Deviation (depression or elevation) from the baseline may indicate myocardial ischemia or injury.