Week 4 - Exercise Stress Testing Flashcards
What should you be aware of when doing a GXT?
- Reason for the test
- Patient history
- Consent
What is graded exercise stress testing (GXT) and what is it used for?
Stress testing, often used for evaluating CV function
What should the patient avoid leading up to a GXT?
- Food consumption at least 2 hours before
- Alcohol
- Cigarettes
- Caffeine
- OTC herbal medications
What measurements are taken in a GXT (4) and when are they taken?
- Heart rate
- Blood pressure
- RPE
- 12 lead ECG
They are taken at rest before exercise, during a progressive test and after the test
What equipment may be used to perform a GXT? (4)
- Treadmill
- Cycle ergometer
- Arm ergometer
- Lifting or workplace tasks
What is the bruce protocol that is used in GXT? When is it okay, what are its limitations?
A table of “stages” with relative speeds and gradients, where someone does 3 minutes at each stage on a treadmill and progresses
+ Good for patients who are not frail
+ Do not have extremely low functional capacity
+ Can handle gradients orthopedically
- Relatively large increments in workload with each stage
- Steepness may lead to immature leg fatigue
What are some alternate treadmill protocols?
- Blake-Ware or Naughton (1-2min stages with increments of 1MET or less)
- Ramp protocols (small increments every 10-15 seconds, perception of effort requires usually less)
When would a cycle stress test be more suitable for a patient? What is the difference between using an electrically or mechanically braking cycle?
If a patient has weight bearing or gait problems
- Electrically braked cycles preferred, cadence not critical
- Mechanically braked cycles - cadence critical
When is an arm ergometer recommended? (6)
- Severe lower-limb orthopaedic problems
- Lower extremity amputation
- Peripheral vascular disease
- Neurological disorders
- Myocardial symptoms present with upper body activity only
What load increases should be used in an arm ergometer?
< 25W
Name two effort/symptom rating scales
- Borg’s Rating of Perceived Effort (RPE)
- OMNI Rating of Perceived Effort
What is a normal GXT response? (4)
- No indications of ischaemia
- No signs of dyshythmias
- Normal haemodynamics (HR and BP responses)
- Reach acceptable workload (MET level)
What are the 3 main types of ECG abnormalities?
- Supraventricular dysrrhythmias
- Ventricular dysrhthmias
- High-grade conduction abnormalities (blocks)
What are the 3 reasons for stopping a GXT?
- Sign or symptom limited (absolute or relative indications)
- Reached predetermined submaximal level
- Maximal level of exertion reached
What are the benefits of GXT? (3)
What groups in the GXT less diagnostic for? (2)
+ Non-invasive
+ Relative cost effects
+ Good value if patient has CV risk factors and/or symptoms
Less Diagnostic:
- <40yo
- < Apparently healthy
What are the reasons for doing GXT? (5)
- Evaluate possible cardiac disease
- Evaluate exisiting cardiac disease
- Evaluate effectiveness of surgical procedures
- Evaluate effect of pharmacological therapy
- Evaluate functional capacity
Why is pre-operative exercise testing beneficial?
Due to the significant risk associated with surgery, it can test multiple body systems under stress and identify and specific risks for surgery complications or mortality, can guide pre-operative pre-habilitation programs
