cardiopulm age related changes

cardiac output

amount of blood pumped by the heart during 1 min

- CO = HR x SV

stroke volume

the volume of blood pumped out of the left ventricle of the heart during each systolic cardiac contraction

- SV = EDV - ESV

VO2max

a measure of the max amount of oxygen your body can utilize during exercise

- VO2 max = 15 x (HRmax/HRrest)

HR max

highest number of beats heart can pump per minute when it's under high stress

- HRmax = 220-age

age related anatomical changes

- siffer, less compliant vascular tissues

- loss of pacer cells from sinoatrial node

- reduced contractility of the vascular walls

- thickened basement membrane in capillary

- reduced baroreceptor sensitivity

stiffer, less compliant vascular tissues have what consequence?

- inc SBP but dec DBP

- dec ventricular filling time

- dec SV and CO

- inc risk for CV disease (ventricular hypertrophy)

loss of pacer cells from sinoatrial node has what consequence?

- slower HR

- dec maxHR

reduced contractility of vascular walls

- slower HR

- dec VO2max

thickened basement membrane in capillary has what consequence?

- dec arteriovenous O2 uptake

- slower exchange

- inc peripheral resistance

- less O2 to skeletal tissue, dec exercise tolerance and circulation

reduced baroreceptor sensitivity has what consequence?

alters autonomic nervous system response

- reason for OH, hypertension, more likely for heat stroke

age related changes - heart size

mostly stays the same

- inc heart wall thickness (inside the heart)

- dec size of atria and ventricles

age related changes - cardiac output

- unaffected at rest with age

- dec during maximal exercise

age related changes - stroke volume

- unaffected at rest with age

- slight inc with maximal exercise

heart rate changes with age are what?

minor

- HRmax dec by 1 bpm/yr

- smaller aerobic workload possible

VO2 max changes with age are what?

dec ~10% per decade from ages 20-60

- dec 15% after 60 yo

heart rate and VO2max changes =

reduced exercise capacity and inc recovery time

things that inc with age

- systolic BP

- SV with exercise

things that dec with age

- diastolic BP

- CO with exercise

- HRmax

- VO2 max

- size of atrium and ventricles

things that stay the same with age

- resting HR

- overall heart size

- CO at rest

- SV at rest

- VO2 max at rest

clinical considerations for cardiac changes

- older adults rely on Frank Starling Method (connective tissue recoil) to compensate

- need to warm up to improve circulation

- correlation between muscle mass and VO2 max

- resistive training to improve VO2max

- anesthesia and older adults (ruins mitochondria)

- **just because things dec does not mean intensity should**

inc lean muscle mass =

inc VO2 max

- more metabolically active

common cardiac conditions

- hypertension

- heart failure

- cardiac dysrhythmias

- coronary syndromes and angina

- valve stenosis

- peripheral vascular disease

- aneurysms

tidal volume

amount of air that moves in or out of the lungs with each respiratory cycle

residual volume

amount of air that remains in a person's lungs after fully exhaling

vital capacity

maximum amount of air a person can inhale after a maximum exhalation

FEV1

amount of air that a person can force out of their lungs in 1 second

PaO2

measurement of oxygen pressure in arterial blood

pulmonary age related changes

- inc in chest wall stiffness

- dec strength of respiratory muscles

- dec lung recoil and compliance

- changes in lung parenchyma

- same # alveoli but larger and thinner

- pulmonary blood vessels thicken (less aVO2 uptake)

pulmonary clinical consequences

- dec vital capacity

- residual volume inc (barrel chest)

- dec gas exchange

- PaO2 falls at a rate of 4 mmhg/decade

- dec FEV1

- total lung volume = unchanged

other pulmonary clinical implications

- dyspnea on exertion (DOE)

- cough mechanism and gag reflex is impaired

- inc risk of aspiration

- prolonged recovery from respiratory illnesses (PNA, flu)

low/mod exercise intensities =

respiratory response is similar to younger adults

higher exercise intensities =

- inc ventilatory cost of work

- inc likelihood of breathlessness

- inc perceived exertion

pathological pulmonary manifestations

- COPD

- restrictive pulmonary disease

- pulmonary HTN

- respiratory infections

- lung cancer

- pulmonary embolism

- pulmonary edema

clinical signs of hypoxia/hypoxemia

- change in mentation (confusion)

- headache

- shortness of breath (SOB)

- tachycardia

- coughing

- wheezing

- bluish color

how to harness intensity safely

by checking vitals

- vitals are vital!