Flashcards in Exercise Prescription Deck (71)
what is the purpose of exercise testing
to observe physiological responses to increasing or sustained metabolic demand.
how long does the test last
continues until the pt. reaches a sign such as ST segment depression or a symptom such as angina or fatigue that limits the maximal level of exertion
why should we use exercise testing
determines a diagnosis such as CAD or abnormal physiologic response
Helps to guide decisions regarding medical treatment and surgical intervention
Evaluates the severity of the disease and provides accurate answers to a patients questions
Evaluates the physiological repsonse to exercise by assessing medical therapy effectiveness and provides appropriate activity guidelines
Provides functional capacity and entrance criteria for CR which helps in determining return to work and writing an appropriate exercise prescription
what are the determinants of prognosis
number of diseased arteries
degree of LVD
>10 METs is good prognosis
< 5 METs is poor prognosis
<3 METs is very poor prognosis
What does each MET increase mean
each increase in exercise capacity= a 13% decrease in all cause mortality and 15% decrease in CV events
what needs to be done prior to clinical testing
get informed consent
educate the pt. on what they may experience (fatigue SOB angina)
obtain a medical hx
what are the relative contraindications to symptom limited max exercise testing
1. Known obstructive left main coronary artery stenosis.
2. Moderate to severe aortic stenosis w/uncertain relationship to symptoms.
3. Tachyarrhythmias w/uncontrolled ventricular rates.
4. Acquired advanced or complete heart block.
5. Recent stroke or transient ischemia attack.
6. Mental impairment w/limited ability to cooperate.
7. Resting HTN w/systolic >200 mmHg or diastolic > 110 mmHg.
8. Uncorrected medical conditions such as significant anemia, important electrolyte imbalance & hyperthyroidism.
what are the absolute contraindications to symptom limited max exercise
Acute myocardial infarction w/in 2 days
Ongoing unstable angina
Uncontrolled cardiac arrhythmia w/hemodynamic compromise.
Symptomatic severe aortic stenosis
Decompensated heart failure
Acute pulmonary embolism, pulmonary infarction or DVT
Acute myocarditis or pericarditis
Acute aortic dissection
Physical disability that precludes safe and adequate testing
what to consider when choosing an exercise modality and protocol
consider the purpose of the test, the specific outcomes desired adn the individual being tested
should you do a submax vs max?
large vs. small increments?
continuous, staged or ramped protocl?
VO2 for TM, bike and UBE
the bike is 5-20% lower VO2 peak than TM
UBE is 20-30% lower VO2 peak than TM
What makes the TM the best mode
it is better able to detect ST segment changes and elicit angina
It also gives a higher peak VO2 and HR
advantages of the bike
BP and ECG are easier to obtain
balance is less of an issue
the RPM on an electronically braked bike gives a more accurate work rate
BUT it may be unfamiliar and end prematurely because of localized leg fatigue
when would it be appropriate to use a UBE
spinal cord injury
post polio syndrome
just remember that the VO2 is 20-30% lower than TM
what is the most widely used protocol
the Bruce TM protocol
what are the disadvantages to the bruce protocol
low function and orthopedic difficulties
the MET increments are large and uneven
it severely limits the # of submax responses
how many stages are there
there are 4 three minute stages
Bruce TM protocol
Bruce Stage I=1.7 mph & 10% grade (4.6 METS)
Bruce Stage II=2.5 mph & 12% grade (7 METS)
Bruce Stage III=3.4 mph & 14% grade (10.5 METS)
Bruce Stage IV=4.2 mph & 16% grade (13 METS)
modified bruce protocol
has 2 stages that can be used prior to starting the bruce
Mod Bruce Stage I=1.7 mph & 0% grade (2.4 METS)
Mod Bruce Stage II=1.7 mph & 5% grade (3.4 METS)
What are the downfalls of the bruce protocol because of its excessive, rapid increments in rate of work
Overestimation of exercise capacity (handrail use, exercise duration or peak workload achieved).
2. Less reliable assessment of therapy effects.
3. Reduced accuracy for detecting CAD.
not reflective of functional capacity due to pt. flunking out early with large jump incline
additional protocols to choose from
Balke-Ware-constant TM speed at 2.0 or 3.3 mph with grade increasing 5% every 2-3 minutes
Unit MET protocol-start at 2.0 METS and increase 1 MET every 3 minutes
when is the ramped protocol used
best used with bicycle or UBE
uses the constant and continuous increase in metabolic demand instead of staning
benefits of ramped protocol
uniform increase in workload results in a steady rise in physiological response and permits a more accurate estimate of VO2
can individualize the ramp rate depending on the pt. characteristics
what measurements are taken during testing
signs and symptoms
why do the most adverse events occur during the cool down stage
redistribution of blood flow to the body
perfusion issues with less functioning muscle pump
what does the accuracy of the test depend on
presence of physiological indicators for ischemia
achievement of at least 85% of APMHR
multiple ECG leads
how can the sensitivity of a test be increased
if the pt. is placed in a seated or supine position immediately following exercise
Interpreting HR Results
normal 10 bpm/1 MET increase. HRmax decrease w/age & meds. Recovery-decrease 12 bpm w/in 1st min or 22bpm w/in 2 min, strongly assoc. w/increased risk of mortality in pts. w/IHD or increased risk for IHD.
interpreting BP results
BP: normal 10mmHg/1 MET increase. Increase w/age, more in men & meds. SBP >250 or increase >140 during test assoc. w/risk for HTN. Hypotensive: SBP below rest or < w/increase work often assoc. w/ischemia, LVD & risk of cardiac events. SBP return to rest w/in 6 min of recovery—poorer prognosis
interpreting ECG results
ECG: dysrhythmias that increase in frequency or complexity assoc. w/ischemia or hemodynamic instability. Ventricular ectopy during exercise but esp. recovery assoc. w/increased risk cardiac arrest.