Exercise stress testing, commonly called TMT (Treadmill Test), is a non-invasive diagnostic procedure that evaluates the heart's response to physical exertion. This functional assessment helps identify coronary artery disease, assess functional capacity and guide therapeutic decisions. At Livasa Hospital, exercise stress testing is performed under strict protocols with experienced cardiologists supervising and interpreting results.

Understanding Exercise Stress Testing

During stress testing, patients exercise on a treadmill while ECG, blood pressure and heart rate are continuously monitored. Exercise increases myocardial oxygen demand. If coronary arteries are narrowed, the increased demand cannot be met, resulting in myocardial ischaemia that produces characteristic ECG changes and symptoms.

Clinical Indications for Stress Testing

Stress testing is recommended for:

• Suspected coronary artery disease – Patients with chest pain characteristics concerning for angina

• Risk stratification – Assessment of prognosis in known CAD

• Post-MI risk assessment – Determining functional capacity after heart attack

• Pre-operative cardiac assessment – Clearance before major non-cardiac surgery

• Asymptomatic high-risk patients – Selected individuals with multiple CAD risk factors

• Arrhythmia investigation – Assessment for exercise-induced arrhythmias

• Exercise prescription – Determining safe activity levels for cardiac patients

Pre-Test Preparation

Patients are instructed to:

• Avoid heavy meals 3–4 hours before testing

• Wear comfortable, loose-fitting clothing and sneakers

• Discuss medications with the cardiologist (some may need to be held)

• Avoid caffeine for 24 hours before testing

• Get adequate sleep the night before

The Treadmill Stress Test Procedure

The test follows standardised protocols:

1. Baseline assessment – Resting ECG, blood pressure and heart rate recorded

2. Equipment placement – ECG electrodes attached to chest; blood pressure cuff applied

3. Warm-up phase – Treadmill begins at slow speed and low incline

4. Progressive exercise – Speed and incline increase at set intervals (usually every 3 minutes)

5. Target heart rate – Patient exercises until reaching 85% of age-predicted maximum heart rate

6. Symptom assessment – Continuous monitoring for chest pain, dyspnoea or other symptoms

7. Cool-down phase – Gradual decrease in intensity after peak exercise

8. Recovery phase – Continued monitoring for 4–5 minutes after exercise cessation

The entire test typically takes 10–15 minutes of actual exercise.

ECG Changes Indicating Ischaemia

Pathological findings suggestive of CAD include:

• ST-segment depression – Most common ischaemic finding

• ST-segment elevation – Indicates transmural ischaemia

• T-wave inversion – May indicate ischaemia or other conditions

• Ectopic activity – Premature beats during or after exercise

The degree, extent and timing of ST changes correlate with disease severity.

Test Termination Criteria

The test is stopped for:

• Achievement of target heart rate – Desired endpoint

• Severe symptoms – Chest pain, dyspnoea, dizziness

• Significant ECG changes – ST-segment depression >3 mm

• Hemodynamic instability – Blood pressure drop >10 mmHg with symptoms

• Arrhythmia – Sustained ventricular tachycardia or other dangerous rhythms

• Fatigue or inability to continue – Patient limitation

Interpretation and Reporting

Results are classified as:

Negative (Normal) Test:

• No ischaemic ECG changes

• Achievement of target heart rate

• Absence of anginal symptoms

• Normal blood pressure response

Positive (Abnormal) Test:

• Diagnostic ST-segment changes

• Symptoms (angina) at low exercise levels

• Inadequate blood pressure response

• Serious arrhythmias

Equivocal Test:

• Non-diagnostic findings

• Further testing may be recommended

Sensitivity and Specificity

Exercise stress testing has:

• Sensitivity 65–75% for detecting significant CAD

• Specificity 85–90%

• Lower sensitivity in women and patients with baseline ECG abnormalities

Advantages and Limitations

Advantages:

• Non-invasive, no radiation or contrast

• Provides functional assessment

• Inexpensive and widely available

• Identifies exercise-induced arrhythmias

Limitations:

• Cannot be performed in immobile patients

• ECG changes may be non-specific

• Lower sensitivity in certain populations

• Cannot localize coronary lesions

Alternative Stress Testing Modalities

When exercise is impossible or contraindicated:

• Pharmacological stress testing – Using adenosine or dobutamine

• Stress echocardiography – Combines stress with echocardiographic imaging

• Myocardial perfusion imaging – Radionuclide assessment of myocardial blood flow

Why Choose Livasa Hospital?

• Experienced cardiologists supervising all stress tests

• Proper equipment and safety monitoring

• Accurate ECG interpretation

• Integrated assessment with other cardiac services

NAP – Contact Details

Livasa Hospital Mohali
Sector 71, Sahibzada Ajit Singh Nagar (SAS Nagar)
Mohali, Punjab – 160071
Phone: +91-80788 80788 (24/7 Emergency)
Website: www.livasahospitals.com

Call +91-80788 80788 to schedule a stress test at Livasa Hospital.