Impaired Capacity Flashcards
What decreases with age?
Cardiac output Max HR Resting and maximal stroke volume Venous return Blood Flow
How does Blood Flow decrease?
25% increase in Left Ventricular thickness
Vessel rigidity
65 yo has 30-40% of aerobic capacity of young adult
What increases with age?
Blood Pressure: both resting & exercise
Cardiac Dysrhythmias
By 75 yo, <10% of SA node cells
Age related changes in the heart
Increase adipose tissue Increase collagen content Decrease muscle cells (myocytes) Decrease innervation/nerve conduction tissue Decrease sympathetic modulation of HR
What do age related in changed in the heart result in?
decrease excitability, decrease cardiac output, venous return and an INCREASE in dysrhythmias
What happens with the walls of the heart become less compliant?
Results in decreased ejection fraction Declines in Left ventricle expansion and contractility (i.e. reduced end diastole volume)
What happens with increased atrial size correlated to left ventricular compliance?
increased workload on the atria
hypertrophy of the aorta
End Diastolic Volume
volume of blood in ventricles before contraction
Preload
End diastolic pressure which is stretching the walls of ventricles to their greatest dimensions
Stoke Volume
Volume of blood ejected from the heart per heartbeat
Stroke Volume
Volume of blood ejected from the heart with each beat
Stroke volume = End diastolic volume – end systolic volume
What does stroke volume depend on?
contractility
preload
afterload
Contractility:
the more forceful the contraction
Preload
the end of stretch of the wall of ventricle
Afterload
the resistance that the ventricle must overcome to eject blood out of left ventricle
VO2
A physiological measure of how much oxygen the body uses at rest or during activity
When will VO2 increase?
Increases in proportion to intensity of exercise/physical activity and will plateau when maximal ability for oxygen delivery is reached, which is maximal oxygen consumption (V·O2 max).
Aerobic Capacity
Ability to provide and sustain energy aerobically
Reflects the body’s ability to take up, deliver, and use oxygen.
Oxygen Consumption (VO2):
Physiological measure of how much oxygen the body uses at rest or during activity. And increases in proportion to intensity of exercise/physical activity and will plateau when maximal ability for oxygen delivery is reached.
VO2 Max:
Maximum amount of oxygen that can be taken in, transported and consumed by the working muscles per minute
Factors Affecting Aerobic Activity
Age
Gender
Training
Physiological Make Up
Age
VO2 max declines with age
After the age of 25 it decreases by 1% each year
Exercise regularly to combat these effects
Gender
Men generally have higher VO2 max
Women have a VO2 max of 15-30% lower
Depends on age and other physiological factors
Training
Fitness testing can determine VO2 max
Training can improve VO2 max by 10-20%
In addition, lifestyle and diet influence VO2 max
For optimum aerobic performance we need
Slow twitch muscle fibers
Mitochondria
Myoglobin stores
Other physiological factors that affect VO2 max
Size of the heart
Size of the lungs
Number of red blood cells
What can affect reconditioning?
Illness
Functional limitations
Restricted activity
Cognitive limitations
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.)
What is included in PT Exam?
History Systems Review Tests and Measures Evaluation, Diagnosis and Prognosis Plan of Care and Interventions
History:
Comprehensive history of a patient with impaired aerobic capacity helps to show contributory factors and to determine appropriate interventions.
Identification of risk factors for cardiovascular disease
Signs and Symptoms highly suggestive of cardiovascular or pulmonary disease
SOB at rest or with mild exertion Pain Discomfort in the chest, neck, jaw, arms, or other areas that may result from cardiac ischemia Orthopnea Paroxysmal nocturnal dyspnea Bilateral ankle edema Palpitations Tachycardia Intermittent leg claudication Known heart murmur Undue fatigue with usual activities
Tests and Measures
Vital Signs
6-Minute Walk Test
Self-Report Measures
Commonly Used Symptoms Scales
Angina Scale
Dyspnea Scale
Claudication Scale
Rating of Perceived Exertion (RPE)
Angina Scale
Mild, barely noticeable
Moderate, bothersome
Moderately severe, very uncomfortable
Most severe or intense pain ever experienced
Dyspnea Scale
Light, barely noticeable
Moderate, bothersome
Moderately severe, very uncomfortable
Most severe or intense dyspnea ever experienced
Claudication Scale
Definite discomfort or pain, but only at initial or modest levels (established, but minimal)
Moderate discomfort or pain from which the patient’s attention can be diverted (e.g., by conversation)
Intense pain (short of grade 4) from which the patient’s attention cannot be diverted
Excruciating and unbearable pain
Systolic BP change during activity?
Systolic BP reflect cardiac output and should also go up in proportion to the metabolic demand of the exercise or activity
Diastolic BP during exercise?
Diastolic BP reflects total peripheral resistance, which remains relatively stable in most people during aerobic exercise
Absolute exercise contraindications:
unstable angina
uncontrolled cardiac dyrhythmias symptoms of hemodynamic compromise
uncontrolled symptomatic heart failure
acute or suspected major cardiovascular event
acute systemic infection
a recent significant change in resting ECG suggestive of ischemia, MI or other cardiac event
Relative exercise contraindications:
known significant cardiac disease severe atrial hypertension tachydysrhythmia or bradydydysrhythmia electrolyte abnormalities uncontrolled metabolic disease chronic infectious disease mental or physical impairment leading to inability to exercise safely
Absolute indications for terminating exercise
Drop in systolic BP or greater than 10mmHG from baseline Moderately severe angina (>2/4) increasing nervous system symptoms signs of poor perfusion subject's desire to stop technical difficulties with equipment sustained ventricular tachycardia ST elevation
