CV exercise physiology & outcome measures Flashcards

1
Q

what is VO2 Max?

A

maximum amount of O2 a person can consume at max physical exertion

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2
Q

why is VO2 max so important?

A
  • most widely recognized measure of cardiopulmonary fitness and aerobic endurance
  • main prognostic indicator of cardiopulmonary morbidity and mortality
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3
Q

what is used to describe exercise intensity?

A

MET = metabolic equivalent of a task

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4
Q

1 MET = _____
- 1 MET equation?

A

amount of energy used for 1 minute of quiet rest
1 MET = 3.5 mL O2 x kg x min
direct correlation to VO2 Max

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5
Q

light exercise ~____ METs (washing dishes, cleaning)
vigorous exercise ~ ____ METs (climbing stairs)

A

2.5-2.8
8.0

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6
Q

what subjective scale is used often in the cardiovascular and pulmonary population where the patient perceives the intensity of exercise?

A

Rate of Perceived Exertion = RPE

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7
Q

what is the difference between max HR and resting HR? aka this is the amount of wiggle room you have to exert your patients

A

heart rate reserve = HRR

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8
Q

what are slow twitch fibers?

A

oxidative
aerobic metabolism: uses O2 + glucose to produce ATP
slows to fatigue
contracts slowly over longer period of timie

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9
Q

what are fast twitch fibers?

A

glycolytic
anaerobic metabolism: uses proteins + glucose to produce ATP with lactic acid byproduct
fatigues quickly
fast contractions for short amount of time

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10
Q

if you are working with a long distance runner, which muscle fibers are going to be working more?

A

slow twitch

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11
Q

if you are a sprinter athlete, which muscles are you primarily working?

A

fast twitch

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12
Q

1st ventilatory threshold (VT1):

A

using aerobic metabolism but with increased exercise you’re using less aerobic metabolism and increasing anaerobic metabolism

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13
Q

2nd ventilatory threshold (VT2):

A

body relies mostly on anaerobic metabolism, virtually no aerobic metabolism

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14
Q

which ventilatory threshold is considered the “walkie talkie” test?

A

1st - you can walk and talk without becoming exhausted

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15
Q

physiologically, what is happening:
– at VT1:
– between VT1 & VT2:
– at VT2:

A

– kidneys release HCO3 once blood lactate levels > 2
– kidneys now can’t keep up with the amount of lactate being produced. blood pH signals respiratory center in brainstem to increase breathing rate to “blow off” excess CO2
– increasing CO2 levels requires us to breathe faster where we can’t maintain a conversation

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16
Q

what’s a good way to monitor that we are keeping our patient in VT1?

A

engage in conversation as you’re walking with them - if talking and walking becomes difficult you are nearing VT2

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17
Q

if your patient is in VT1, what RPE rating does that correlate with?

A

11-13/14

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18
Q

what is the most important noninvasive procedure used in the diagnosis and management of patients with CAD?

A

graded exercise testing (GXT)

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19
Q

what is GXT?

A

systematically and progressively increasing O2 demand and evaluating the responses to increased demand

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20
Q

what are risk factors for needing exercise testing performed?

A

men > 45, women > 55
family history of heart attack or sudden death
smoking
sedentary lifestyle
obesity
hypertension
dyslipidemia
pre-diabetes

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21
Q

_____% of HRmax is considered low intensity exercise
_____% of HRmax is considered moderate intensity exercise
____% of HR max is considered vigorous intensity exercise

A

50-63%
64-76%
77-93%

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22
Q

assign the proper risk category for each of the following:
– asymptomatic, < 2 risk factors
– asymptomatic, >/= 2 risk factors
– symptomatic or known CV, pulmonary, renal or metabolic disease OR major S&S of CV, pulmonary, or metabolic disease

A

– low risk
– moderate risk
– high risk

23
Q

a patient is considered low risk. are they required to perform GXT or have a medical exam done before exercising?

A

no

24
Q

a patient is asymptomatic but has 4 risk factors for activity. should they have a medical exam or GXT assessed before exercise? what about MD supervision?

A

medical exam - no for moderate intensity exercise,
yes for vig. ex.
no MD supervision.

25
Q

a patient at high risk for CV events with exercise should have what done prior to exercise? specify for moderate and vigorous exercise.

A

medial exam (mod & vig.) - both
GXT (mod & vig) - both
MD supervision of exercise test (mod & vig) - both

26
Q

indications for performing GXT (5)

A

atypical chest pain
CAD evaluation
pre-participation exercise screening
functional assessment
assessment of arrhythmia, HTN, other instability with exercise

27
Q

absolute contraindications for GXT:

A

recent (<4-6 weeks) MI
recent change to ECG
cardiac infection
unstable angina
decompensated HF
severe or symptomatic aortic stenosis
acute PE
2nd or 3rd degree AV heart block
unstable arrhythmia causing hemodynamic instability
any acute illness

28
Q

relative contraindications for GXT

A

ST depression on resting ECG
significant or uncontrolled HTN
L main CAD
valvular heart disease
compensated HF
cognitive impairment
uncontrolled metabolic disease
tachyarrhythmia or bradyarrhythmia
electrolyte abnormalities
MSK conditions

29
Q

what do you need to have first before performing GXT? (3)

A
  • signed informed consent
  • availability of appropriate equipment and supplies to manage an emergency (AED)
  • knowledge of:
    — when to exclude patients from GXT
    — when to terminate GXT
    — skills needed to react to abnormal response or situation
30
Q

when is low level GXT usually performed in the CV population?

A

shortly after MI or CABG

31
Q

what is low level GXT good for?

A

predicting subsequent course
identifying high risk pt not typical for CR
good screen for cardiac or pulmonary rehab participation

32
Q

what are examples of low level GXT?

A

gait speed
5xSTS
6MWT or 2MWT

33
Q

what is the most valuable indicator from low level GXT of poor prognosis after MI?

A

ST depression > 2.0 mm during low level GXT

34
Q

during low level GXT, your patient showed early onset ST depression. what is that related to?

A

increased incidence of coronary events

35
Q

if low level GXT induces ventricular arrhythmias, the patient has a 2.5x higher chance of what?

A

sudden cardiac death

36
Q

during low level GXT your patient was only able to perform exercise for a short duration. what is that highly correlated with?

A

incidence of HF and increased mortality

37
Q

if you are performing a submax GXT, when do you terminate the test? max GXT?

A

predetermined end point, usually 85% max HR
at max HR or symptom limited

38
Q

what does a submax test measure? max?

A

measures cardiorespiratory fitness levels
better for CAD/CVD

39
Q

what are the protocols for low level & submax GXT protocols?

A

vitals before, during, after
education on test
warm up
monitor HR at least twice per stage
terminate at 85% max HR
cool down
continuous monitoring during recovery until pretest values reached

40
Q

what patient type is the bruce treadmill test protocol most widely used for?

A

athletic population

41
Q

true or false. bruce treadmill test is a max GXT only

A

false - can be both max and submax

42
Q

what is bruce treadmill test most used for?

A

functional capacity prediction

43
Q

protocol of bruce treadmill test:

A

start at 1.7 mph –> increase every 3 minutes
start at 10% grade –> increase 2% every 3 minutes

44
Q

what is the Balke test?

A

submax GXT test used largely for athletic population

45
Q

Balke test protocol:

A

stay at 3.3 mph
starts 0% grade, increase to 2% after 1 minute
after 2 minutes and each further minute, incline increases 1%

46
Q

YMCA Step test protocol:
– what type of GXT?

A

12 inch step at 24 steps/minute x 3 minutes
HR measured 1 minute post-test
compare max and 1 minute recovery to age-related norms
– submax

47
Q

12-minute run test (Cooper’s Run Test) protocol:
– what type of GXT?

A

measure distance run or walked in 12 minutes
compare to norm table
– submax

48
Q

Astrand-Rhyming Cycle Ergometer Test protocol:
– estimates? so… what type of GXT?

A

6 minute cycling with pre-determined wattage setting for 50 rpm
goal is to reach steady state HR between 125-170
– estimates VO2 max … submax test

49
Q

wingate maximal exercise test protocol:
– type of GXT?

A

after warm up:
- 30 sec resistance free max speed pedaling
- resistance added at pre-determined level
- pedal as long as possible
– maximal test –> used in athletic & training situations, think NFL draft

50
Q

if you are performing a low level or submax test, when should you terminate the assessment?

A

angina
reaching 6 METs
poor perfusion
claudication
SBP decrease with increased workload
BP > 250/115
1-2 mm ST depression
> 9 PVCs/minute –> multifocal PVCs absolute contraindication to exercise
any ventricular arrhythmia
subject request to stop test

51
Q

why would a pharmacologic stress test be used over GXT?

A

if patient is unable to perform a standard treadmill or cycle stress test
– can they tolerate surgical or medical intervention

52
Q

pharmacologic stress test protocol:

A

medication injected to induce physiologic stress
all the rest is the same… watch vitals and response to exertion

53
Q

where would a pharmacologic stress test be conducted most often?

A

acute care setting or cardiologist office