Lectures 5 and 6 for exam 1 Flashcards
1
Q
Why is there a need for clinical exercise testing?
why is there a need/ what kinds of patients come for exercise testing?
A
risk stratification/ risk assessment
- evaluate cause of symptoms (angina pectoris, dyspnea, leg pain) - cardiopulmonary disease
- risk stratification- patients considered for coronary revascularization
- risk stratification for non cardiac surgeries
Evaluation of effectiveness of interventions
Develop exercise prescription
Evaluation for return to work
2
Q
Contraindications to exercise
A
- absolute contranidication: except in extraordinary cases, which must be actively decided by both the referring and supervising physician on a case-by-case basis (patient should not perform exercise test)
- Relative contraindications: consider stress testing relative to benefits gained, outweigh the risks (decision based on what is better management of patient)
3
Q
Absolute contraindications to exercise testing
A
- recent change in resting (ECG suggesting significant ischemia,k recent myocardial infraction or other acute cardiac event)
- unstable angina
- uncontrolled symptomatic heart failure
- symptomatic severe aoritc stenosis
- uncontrolled cardiac dysrhythmias causing symptoms or hemodynamic compromise
- acute pulmonary embolus or pulmonary infarction
- acute myocarditis or pericarditis
- suspected or known dissecting aneurysm
- acute systemic infection, accompanied by fever, body aches, or swollen lymph glands
4
Q
Relative Contraindications to exercise testing
A
- left main coronary stenosis
- moderate stenotic valvular heart disease
- electrolyte abnormalities (hypokalemia or hypomagnesemia)
- sever arterial hypertension (systolic BP of greater than 200 mmHg and /or diastolic BP of greater than 110 mmHg) at rest
- tachydysrhythmia or bradydysrhythmia
- hypertrophic cardiomyopathy and other forms of outflow tract obstruction
- neuromotor, musculoskeletal, or rheumatoid disorders that are exacerbated by exercise
- high degree atrioventricular block
- ventricular aneurysm
- uncontrolled metabolic disease (diabetes, thyrotoxicosis, myxedema)
- chronic infectious disease (HIV)
- mental or physical impairment leading to inability to exercise adequately
5
Q
Modalities and Protocols for exercise testing
A
- treadmill
- cycling ergometer
- arm bike ergometer
- swimming
- rowing ergometer
6
Q
Why use treadmill for exercise testing?
A
- common and familiar
- use of greater muscle mass (puts higher demand on the body)
- Greater MET level, higher maximal HR, higher rate pressure product (HR x SBP)
more difficult to obtain accurate BP and ECG bc of motion; handrails should not be used- can impact estimation of exercise capacity
7
Q
What is rate pressure product?
A
- HR x SBP
- surrogate for myocardial oxygen uptake (how much O2 the heart is using)
- linear relationship between myocardial oxygen uptake and BOTH coronary blood flow and exercise intensity
8
Q
used on treadmill
Bruce protocol
A
- 3 minute stages
- start at 1.7 mph, 10% grade
- increase both speed (about 0.8 mph) and grade (2%)
- increase in both speed and grade causes HR, BP, etc to increase faster
- used for more fit people to achieve a VO2 max
9
Q
Used on treadmill
Modified Bruce Protocol
A
- more standardized
- 1 min stages
- start at 1.4 mph at 0% grade
- Stage 2 = 1.7 mph at 5% grade
- Stage 3 = 1.7 mph at 10% grade
- gradual progression of increase speed and increase grade
- Both speed and grade increase at the same time
- more gradual than bruce protocol (for less athletic people)
10
Q
Used with treadmill
Modified Balke Protocol
A
- more standardized
- 2 min stages (depends on purpose of test, if want to find submax, longer stages = better)
- choose 2.0, 2.5, 3.0, or 3.5 mph for prefferred walking speed
- start at 0% grade
- increase 2.5% grade each stage
- Speed stays same and grade increases
11
Q
used with treadmill
Modified Naughton Protocol
A
- 2 min stages
- start at 2.0 mph and 0% grade
- 1st progress in grade 3.5% up till 17.5%
- then increase speed to 3.0 mph and decrease grade to 12.5%
- progress like this; keep one constant and adjust other speed vs. grade
12
Q
Used on treadmill
Protocol-independent
A
- Stare walking at 0% grade
- aske patient if want to increase speed OR grade
- depends on preference/ goal of exercise
- more individualized than other protocols
13
Q
Cycling Ergometer
A
- for ambulatory, orthopedic, or peripheral vascular limitations
- less expensive, more portable, can get BP and ECG readings easier
- Lower max MET value - lower HR, higher SBP than treadmill (overall less muscle mass involved)
- Work rates can be more easily adjusted in smaller increments (Watts)
- Concerns: localized leg fatigue before cardiovascular max reached ( underestimation of VO2 max), maintain pedal rate, less familiar with exercise mode for some
14
Q
Used with cycling
Astrand-Rhyming cycle ergometer test
A
- single-stage 6 min test
- variable for test is HR
- pedal rate set at 50 rpm
- Goal: obtain HR between 125-170 bpm (HR measured in 5th and 6th minute of work each stage) - avg of HRs used to estimate VO2 max
- suggested work rates based on sex and fitness status: men, unconditioned = 300 or 600 kgm/min (50 or 100W); men, conditioned = 600 or 900 kgm/min (100 or 150W); women, unconditioned: 300 or 450 kgm/min (50 or 75W); women, conditioned: 450 or 600 kgm/min (75 or 100W)
15
Q
Used with cycling
Modified YMCA
A
- flexibility based on goal and individual
- multi-stage submax test
- 2-4 x 3 min stages
- constant pedal rate of 50 rpm
- Stage 1 = pedal against 0.5 kg resistance (25W; 150 kgm/min)
- Stage 2 = workload is based on steady state HR from last min of stage 1 (Hr - less than 80bpm change resitance to 2.5kg, 125W, 750 kgm/min; HR 80-89 bpm change resistance to 2.0kg, 100W, 600kgm/min; HR 90-100bpm change resistance to 1.5kg, 75W, 450kgm/min; HR greater than 100bpm change resistance to 1.0kg, 50W, 300kgm/min)
- Stage 3 and 4 = goal to have 2 consecutive stages with HR between 110bpm and 70% of HRR (85% of HR max)- resistance increased by 0.5kg, 25 W, 150kgm/min
16
Q
Arm cycling ergometer
A
- use if patient cann’t do lower body exercise
- because of low demand/ stress good for someone who experienced a cardiac event
- Concerns; less muscle mass involved (lower VO2 peak), difficulty in obtaining BP and ECG, test edpoint is often arm fatigue rather than cardiovascular max
- Bc of concerns, this is often replaced with pharmaologic stress testing
17
Q
Clinical Exercise Testing in General
A
- Role of CEP= not to diagnose individuals but offer advice
- diagnostic procedure - physician oversees and always available
- allow familiarization with exercise mode
- mode of exercise should utilize large muscle groups unless the patient has orthopedic or peripheral limitations
- avoid isometric contractions ( gripping handrails or handle bars)
- start well below maximal evels to get baseline then increase gradually
- should last 8-12 minutes (2-3 minute stages), ramped protocols should have a gradual and regular increase in workload
18
Q
Parameters that need to be considered for exercise testing
A
- room conditions ( room temp should be about 20 degrees celsius or 72 degrees farenheit with less than 60% humidity; ideal with a fan to help cool and ventilate patient)
- exercise laboratory has appropriate exercise modalities (treadmill, bike, arm ergometer)
- lab should have monitoring equipment (ECG, BP, O2 saturation, VO2)
- lab should have emergency items (defibrillator, drug cart, first aid)
- appropriately trained personnel (physicians, nurse practioners, physician assistants, CEPS) should be present or rapidly available ( in less than one min) to assure patient safety
19
Q
CEP should have knowledge of:
A
- indications for exercise testing
- alternative physiological cardiovascular tests
- contraindications, risks, risk assessment of testing
- recognize and treat complications during exercise testing
- ability to resuscitate and have successful completion of advanced cardiovascular life support course
- various protocols and indications for each
- basic cardiovascular and exercise physiology (hemodynamic response to exercise)
- cardiac arrhythmias (recognize and treat)
- cardiovascular drugs and how effect exercise performance, hemodynamics, and ECG
- effects of age and disease on hemodynamic and ECG response to exercise
- principles and details for exercise testing- ex. proper placement of electrodes and skin preparation
- endpoints of test and indications ot stop exercise
