Lecture 11 - Graded Exercise Stress Testing Flashcards
What is a graded exercise stress test (GXT)?
A graded exercise stress test (GXT), often referred to as exercise stress testing, is a diagnostic procedure used to evaluate cardiovascular (CV) function.
What is the value of a GXT?
• Non-invasive
• Relatively cost effective
• Good diagnostic value
When would a GXT be necessary?
• Rule out coronary disease, • Evaluate possible CV disease symptoms, • Evaluate severity of disease, • Estimate prognosis after MI, • Stratify risk associated with physical activity, • Evaluate disease progression
What are the considerations if you are involved in a GXT
- Understanding the purpose of the test and patient’s medical history is crucial.
- Patient history should include cardiac symptoms, hypertension, orthopedic conditions, recent illness, and exercise history.
- Consent form should be checked.
- Skin preparation for ECG electrodes involves removing body hair, cleaning the skin with alcohol swabs, and lightly abrading the skin.
How should patients prepare for a GXT?
Patients should understand the testing process, including electrode attachment and exercise.
Proper attire, including suitable clothing and footwear, is advised.
Patients should avoid consuming food, alcohol, cigarettes, caffeine, and certain medications before the test.
Doctors should inform patients about whether to continue taking prescribed medications.
What measurements are involved in a GXT?
Heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), and 12-lead ECG monitoring.
What are the baseline measurements that are gathered pre-GXT?
Baseline measurements are taken at rest before exercise, both supine and standing, during progressive exercise, and post-exercise.
Describe the GXT most widely used and the protocol
Bruce protocol: 3 mins at each stage for 10 stages. start at grade 10 (2.7km) and work to a grade 28 (12.1km)
What are the limitations to the bruce protocol
Relatively large increments in workload
with each stage
• Long (3 min) stages at some workloads
problematic re walk or run
• Steepness may lead to premature leg
fatigue (vs C-R limitations)
What are some individual considerations of the bruce protocol?
• frail
• have extremely low Functional
Capacity
• cant handle gradient orthopedically
When would we use a cycle test over a treadmill GXT test?
Non-weightbearing or treadmill not working
When is the arm egometer recommended?
– Severe lower-limb orthopaedic problems
– Lower extremity amputation
– Peripheral vascular disease
– Neurological disorders
– Myocardial symptoms present with upper body activity
only
– Return to work after MI involves extensive upper body
activity
During the Balke-Ware or Naughton TM protocol, what is the duration of stages and the increments we use?
1-2min stages. Increments of 1MET or less
What is a normal response to a GXT
GXT normal if:
• No indications of ischemia (e.g. ST depression)
• No signs of dysrhythmias on ECG
• Normal haemodynamics (HR and BP responses)
• Reach acceptable workload (MET level) on GXT
When analysing heart rhythm using an ECG, what are the 3 types of abmormalities?
– Supraventricular dysrhythmias (tachycardia)
– Ventricular dysrhythmias (ventricular fibrilation)
– High-grade conduction abnormalities
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