1. What is the Mayo Clinic Stress Test METs Calculator?

The Mayo Clinic Stress Test METs Calculator estimates metabolic equivalents (METs) achieved during cardiac stress testing using standardized protocols. METs represent the energy cost of physical activities as multiples of resting metabolic rate.

2. How Does the Calculator Work?

The calculator uses protocol-specific equations to estimate METs:

Where:

• Protocol-specific — Different exercise protocols have predetermined MET values for each stage
• Stage — The level or phase of the stress test protocol
• Duration — Time spent at each stage (for custom protocols)

Explanation: Different stress test protocols (Bruce, Modified Bruce, Naughton) have standardized MET values assigned to each stage of the test.

3. Importance of METs Calculation

Details: METs measurement during stress testing helps assess cardiovascular fitness, functional capacity, and prognosis in patients with heart disease. Higher achieved METs generally indicate better cardiovascular health.

4. Using the Calculator

Tips: Select the appropriate stress test protocol, enter the stage reached during testing, and for custom protocols, include the duration at each stage.

5. Frequently Asked Questions (FAQ)

Q1: What are METs in exercise testing?
A: METs (Metabolic Equivalents) represent the ratio of working metabolic rate to resting metabolic rate. One MET is defined as the energy cost of sitting quietly.

Q2: What is a good METs score on a stress test?
A: Generally, achieving 10+ METs indicates excellent functional capacity, while less than 5 METs suggests poor functional capacity. Interpretation varies by age and gender.

Q3: What's the difference between Bruce and Modified Bruce protocols?
A: The Bruce protocol starts at 1.7 mph/10% grade, while the Modified Bruce starts at 1.7 mph/0% grade, making it easier for less fit or cardiac patients.

Q4: How accurate are these METs estimates?
A: Protocol METs values are standardized estimates. Actual energy expenditure may vary based on individual factors like weight, efficiency of movement, and test conditions.

Q5: Can METs predict cardiovascular risk?
A: Yes, achieved METs during stress testing is a strong predictor of cardiovascular events and overall mortality, with each 1-MET increase associated with approximately 10-15% improvement in survival.