Cardiopulm Issues Across Lifespan

Question 1

Normal HR for Adult vs Infant

Answer 1

Adult 60-70 BPM, Infant 110-160 BPM

Question 2

Normal BP for Adult vs Infant

Answer 2

Adult 120/80 Infant 75/50

Question 3

Normal RR for Adult vs Infant

Answer 3

Adult 12/min infant 30-40/min

Question 4

Normal Tidal Volume for Adult vs Infant

Answer 4

Adult 500 ml, infant 20 ml

Question 5

Normal PaO2 for Adult vs Infant

Answer 5

Adult 95mmHg, infant 75-80mmHg

Question 6

Normal PaCO2 for Adult vs Infant

Answer 6

Adult 40mmHg, infant 33mmHg

Question 7

Normal pH for Adult vs Infant

Answer 7

Adult 7.40, infant 7.33

Question 8

What is the equation for HRR?

Answer 8

HRR=

RHR + (50- 85%)(Max HR – RHR)

Question 9

From childhood to adolescence/ adulthood what happens to VO2max?

Answer 9

Generally VO2max increases through childhood to adulthood.

Question 10

As people age, what happens to resting HR and maximal HR?

Answer 10

resting HR increases

HR max decreases

Question 11

What happens to alveoli as people age?

Answer 11

with age the alveoli get larger and fewer in number

Question 12

From a respiratory viewpoint, what patient population do people start to look like with advanced age?

Answer 12

COPD patients

Question 13

How does aging affect these respiratory factors?: FEV1, FVC, TLC, vital capacity, functional respiratory capacity, residual volume, DLCO/VA

Answer 13

FEV1 - decreased, FVC - decreased, TLC - unchanged, vital capacity - decreased, functional respiratory capacity - increased, residual volume - increased, DLCO/VA - increased

Question 14

What happens to elastic recoil of lungs as we age?

Answer 14

Decreases, therefore muscles have to work harder to fully exhale.

Question 15

Is the work of breathing greater for an older individual compared to a younger individual?

Answer 15

Yes, older individual works harder to breath

Question 16

What contributes to a decrease in chest wall compliance? (“thoracic rigidity”)

Answer 16

Calcification of intercostal cartilage.
Arthritis of costovertebral joints.
↓ contribution of intercostal muscle to effective ventilation.“thoracic rigidity”
↓ diaphragm strength/ force generation
↓ MIP & ↓ MVV
Age related decline in Type II fibers combined with atrophy

Question 17

Functional consequences of respiratory changes with aging?

Answer 17

Increased energy expenditure for breathing (O2 cost of breathing; ↑ work of breathing)
Decreased gas exchange efficiency
↑ risk of hypoxemia
Increased ventilation compared to younger at same work loads
? Related to ↑ dead space (VD/ VT)
Altered lung & chest wall mechanics - ↑ stiffness/ ↓ compliance
Altered V/Q relationships

Diminished cough reflex
↓ pulmonary defense
Increased susceptibility to respiratory infections

Question 18

As we age the arteries become stiffer (less compliant). What happens to the left ventricle in an older person?

Answer 18

becomes thicker b/c of decreased artery compliance and resultant increased after-load.

Question 19

The 4 determinants of myocardial aging?

Answer 19

preload, afterload, heart rate, contractility

Question 20

What factors make up TPR (total peripheral resistance)?

Answer 20

pulmonary vascular resistance + systemic vascular resistance

Question 21

What is more accurate max heart rate estimation for elderly than 220-age?

Answer 21

220-age + 15.

Question 22

what is the advantage of using the cardiac index?

Answer 22

It normalizes the cardiac output measurement for body size.

Question 23

What happens with Aging and factors of the cardiac muscle?

Answer 23

↑ LV wall  thickness
↓ myocyte #
↑ lipid deposition; ↑ fibrosis & collagen
↓ heart compliance
Impact on filling ???
“diastolic dysfunction”

Question 24

What happens with Aging and factors of the cardiac valves?

Answer 24

↑ thickness & calcification
Alters filling & ejection
Afterload stressor

Question 25

What happens with Aging and factors of the cardiac conduction system?

Answer 25

↑ atrophy and fibrosis ↓ # of SA node pacemaker cells ↑ risk of dysrhythmia ~ 10% of population >70 y/o have atrial fibrillation

Question 26

What happens with aging and the vascular system?

Answer 26

``` Large arteries dilate ↓ dilatation reserve ↑ arterial stiffness (↓ arterial compliance) intima: ↑ heterogeneity of endothelial cell subendothelial wall thickens media: ↑ size of smooth muscle layer ↑calcification & collagen deposition Fragmentation & atrophy of elastin HTN ↑ LV hypertrophy/ heart failure ```

Question 27

What happens with aging and the heart rate factors?

Answer 27

resting HR w/o change ↓ maximal HR HR is ↑ @ submaximal workload (compared to younger) ↑ risk of ECG abnormalities

Question 28

What happens with aging and the stroke volume factors?

Answer 28

SV tends to ↓ as a function of age

Question 29

What happens with aging and loading conditions of heart?

Answer 29

preload: ↓ early diastolic filling ↑ atrial contribution “diastolic dysfunction”

Question 30

What happens with aging and afterload?

Answer 30

``` Afterload: ↑ resistance to outflow from LV ↑ BP/ HTN ↑ predominately in SBP related to: ↑ TPR  aortic stiffness ↓ peripheral vascular bed may result in ↓ SV & CO  ventricular hypertrophy ```

Question 31

What are some neurohumoral changes in the heart with aging?

Answer 31

Sympathetic nervous system activity increases ↑ circulating catecholamines Parasympathetic nervous system activity decreases ↓β- adrenergic responsiveness Blunted post-synaptic responses ? ↑ α-adrenoreceptor responsiveness Baroreceptor sensitivity decreases ↑ orthostatic intolerance/ ↑ risk of postural hypotension/ syncope

Question 32

What cardiac factors have a training response in elderly people?

Answer 32

max HR doesn't change much. Can increase cardiac output with increase in stroke volume

Question 33

What factors do we need to change for exercise prescription in Elderly?

Answer 33

↑ warm up time/ ↑ cool down time required ↑ time required to reach physiologic steady state ↓ responsiveness of cardiovascular system ↓ fitness levels

Question 34

What are benefits of exercise in elderly?

Answer 34

↑ in VO2 max ↑ CO; ↑ SV Resting CV Function: ? ↓ in resting HR & BP Submaximal Workloads: ↓ HR & BP @ submax workloads ? ↑ EF/SV Peripheral changes ↑ (A-V) O2 difference ↑ muscle mass; ↑ capillary density; ↑ aerobic enzymes