Impaired Aerobic Capacity and Endurance Flashcards
Cardiac output, max HR, resting and maximal stroke volume, and venous return all ______ as one ages
decrease
Blood flow decreases as one ages due to what?
Vessel rigidity
Blood flow also decreases because the left ventricle thickens by __%
25
A person 65 years old has __-__% the aerobic capacity of a young adult
30-40
What 2 cardiovascular factors increase as one ages?
BP and dysrhythmias
By the age of 75 we will have less than __% of pacemaker cells in the SA node in comparison to young adults
10
Increases what 3 things and decreases in what 3 things results in decreased excitability, decrease cardiac output, venous return and an increase in dysrhythmias.
Increased adipose tissue, collagen content, and cardiomyocyte senescence
Decreased muscle cells (myocytes), innervation/nerve conduction tissue, and sympathetic modulation of HR
What are 2 things that occur due to reduced compliance of the heart walls?
- reduced EDV
- decreased ejection fraction
As the left ventricle becomes less compliant the atria _____ in size
increase
As stroke volume increases EDV _____.
increases
What is the myocardium’s response to reduced cardiac output due to increased age?
Increasing muscle mass which provides a short-term enhancement in cardiac output but results in long-term effects on cardiac function
Ventricular hypertrophy results from an increase in the size of individual cardiomyocytes. This can be physiological and reversible or irreversible. What causes each?
- reversible exercise-induced
- reversible disease-based
As one ages heart valves thicken and calcify resulting in heart murmurs. What valves have the most issues?
Mitral and Aortic
The incidence of sick sinus syndrome (SSS) increases with age. What are 3 things tat result?
- Bradycardia
- SA node arrest
- SA exit conduction block
Approximately __% of older adults have cardiac conduction abnormalities at rest.
50
What are 4 ECG changes that occur as one ages?
- PR and QT intervals have small increases
- ST segment becomes flattened
- Amplitude of the T wave diminishes
What can be defined as a physiological measure of how much oxygen the body uses at rest or during activity?
Oxygen consumption (V·O2)
Maximal oxygen consumption is directly related to what?
aerobic capacity
What are 4 factors that affect aerobic capacity?
- Age
- Gender
- Training
- Physiological Make Up
By the age of __ VO2 max
decreases by 1% each year
25
Explain the gender differences in regards to VO2 max
Women tend to have a lower VO2 max anywhere from 15-30%
Training can improve VO2 max by __-__%
10-20
What are 3 physiological factors that are required for optimum aerobic performance?
- Slow twitch muscle fibers
- Mitochondria
- Myoglobin stores
What are 3 other physiological factors that affect VO2 max?
- Size of the heart
- Size of the lungs
- Number of red blood cells
What are 4 factors that influence decreased physical activity (deconditioning)?
- Illness
- Functional limitations
- Restricted activity
- Cognitive limitations
What are 2 age related physiological changes?
- Reduced maximal oxygen consumption secondary to decreased cardiac performance and skeletal muscle endurance
- Conditions that affect functional mobility (stroke, Parkinson’s disease, osteoarthritis, bone fractures etc.)
Moderate to strong evidence has been shown that regular physical activity can do what 2 things?
- result in better functional health
- reduce abdominal obesity
Moderate evidence has been shown that regular physical activity can do what 6 things?
- lower risk of hip fracture
- lower risk of lung cancer
- lower risk of endometrial cancer
- weight maintenance after weight loss
- increase bone density
- improve sleep quality
How do you calculate oxygen consumption (VO2)?
VO2 = cardiac output x AV oxygen difference
How do you calculate cardiac output?
SV X HR
HR increases with increasing workload via what 2 mechanisms?
1) At less than 100 bpm heart rates increases via an inhibition of vagal (parasympathetic) tone.
2) As HR approaches 100 bpm heart rate increases primarily by stimulation of sympathetic tone.
SV during acute aerobic exercise increase linearly up to intensities of __-__% of maximal oxygen consumption and then plateaus.
40-60
What reduces stroke volume?
Any pathological process that reduces ventricular filling or emptying
What increases stroke volume?
aerobic exercise training
What is resting CO?
5 L/min
With exercise CO can increase up to __-__ L/min
20-40
With aging, maximal cardiac output declines secondary to decreases in what 2 things?
HR and SV
With aging, sedentary people show a(n) ______ in arteriovenous oxygen difference during aerobic exercise.
decline
What are 4 commonly used symptoms scales used to assess aerobic capacity?
- Angina Scale
- Dyspnea Scale
- Claudication Scale
- Rating of Perceived Exertion (RPE)
Describe the 4 ratings of the angina scale
1) Mild, barely noticeable
2) Moderate, bothersome
3) Moderately severe, very uncomfortable
4) Most severe or intense pain ever experienced
Describe the 4 ratings of the dyspnea scale
1) Light, barely noticeable
2) Moderate, bothersome
3) Moderately severe, very uncomfortable
4) Most severe or intense dyspnea ever experienced
Describe the 4 ratings of the claudication scale
1) Definite discomfort or pain, but only at initial or modest levels (established, but minimal)
2) Moderate discomfort or pain from which the patient’s attention can be diverted (e.g., by conversation)
3) Intense pain from which the patient’s attention cannot be diverted
4) Excruciating and unbearable pain
According to the 10-grade Borg Scale what do the following scores indicate in terms of RPE?
0, 2, 3, 5, 7, 10
0 = nothing
2 = slight
3 = moderatre
5 = severe
7 = very severe
10 = maximal
Describe BP changes in response to exercise
Systolic goes up proportionately to metabolic demand
Diastolic remains relatively stable
What are the 6 absolute contraindications to exercise?
- unstable angina
- uncontrolled cardiac dysrhythmias causing symptons of hemodynamic compromise
- acute or suspected major CV event
- acute systemic infection, accompanied by fever, body aches, or swollen lymph glands
- a recent significant change in resting ECG
What are the 6 relative contraindications to exercise?
- known significant cardiac disease
- severe arterial HTN (>200/110)
- tachydysrhythmia or bradydysthymia
- electrolyte abnormalities
- uncontrolled metabolic disease
- chronic infectious disease
- mental or physical impairment leading to inability to exercise safety
What are the 8 absolute indications for terminating exercise?
- drop is systolic BP > 10 mmHg when accompanied by other evidence of ischemia
- moderately severe angina (>2/4)
- increasing nervous system symptoms
- signs of poor perfusion
- subject’s desire to stop
- technical difficulty with monitoring equipment
- sustained ventricular tachycardia
- ST elevation in leads without diagnostic Q-waves
What are the 7 relative indications for terminating exercise?
- drop in systolic BP > 10 mmHg without other evidence of ischemia
- increasing chest pain
- hypertensive response (?250/115)
- fatigue, SOB, leg cramps, or claudication
- ST or QRS changes (>2mm ST-segment depression)
- Arrhythmias other than sustained ventricular tachycardia
- development of bundle-branch block or intraventricular conduction delay that cannot be distinguished from ventricular tachycardia
If BP is greater than ___ bpm exercise is contraindicated
150
