Ex Phys final: Cardiovascular 3

Fick equation

VO2= Q(CO) x a-v O2 diff

VO2

Oxygen consumption, the rate at which oxygen is consumed by body tissues

Q

efficiency of delivery of O2

a-VO2 diff

1. Efficancy of tissue O2 extraction/consumption

2. Oxygen contact in arterial system (O2 into tissue) and oxygen content in venous system (O2 out of tissue)= oxygen consumed by tissue

3. If the number is small, more O2 in venous system= tissue not extracting and consuming oxygen

Cardiac issue (Q)

tissue cannot consume enough oxygen if heart/blood cannot supply it (low Vo2 due to low CO)

Muscle mass issue (O2 diff)

if tissue cannot extract and consume oxygen brought to it

Frequency

1. Exercise should be carried out 3-5 days a week

2. Determines chronic cardiovascular adaptations

3. Increased SV: regular increases in SV increases chamber size= increase in muscle mass of LV

4. Increase in LV muscle mass will increase SV and decrease HR= CO getting greater contribution from SV

5. Decreased resting and submax HR

6. Increased endothelial function and vascular compliance

7. <3 days a week no change in VO2 max but may have functional improvements

Intensity

1. Primary driver of acute cardiovascular load /increased cardiac work

2. Increase SV, HR, CO

3. Excessive intensity--> exaggerated BP response

4. measure with HR, O2 stats, and RPW

Time

1. Total of 20-60 minutes of continuous or intermittent aerobic activity per day

2. Divided into a min of 10-min bouts throughout the day

3. Duration of training is dependent on intensity

4. At the lower end of training band, need to sustain longer to achieve effects

5. Sustains cardiovascular demand overtime

6. Influences plasma volume shifts and thermoregulation

7. Prolonged exercise (>10-15 mins) -> cardiovascular drive (skin blood flow and plasma depletion)

Cardiovascular drift

HR and RPE increase tremendously-> starting to thermoregulate with blood: heart works harder for vascular bed in skin to open up

Type

1. Aerobic like walking, jogging, biking more effective

2. Strength should be with dynamic to avoid cardiovascular strain

3. Determines muscle mass recruited and posture

4. Alters venous return and peripheral resistance

5. Affects pressor responses and BP safely

Customizing frequency

Proritize when health intensions are related to chronic disease prevention, SOB-> scary-> avoid

Customizing intensity

greatest impact on weight loss and athletic conditioning

Customizing timing

pertinent for people with diabetes and blood sugar dysregulation

Customizing types

Include all types but remembering disease processes: including jogging to best for knee OA

Expected HR responses with exercise

1. Increase HR linearly with increased work load

2. Decreased HR recovery post exercise

3. Blunted HR response with beta blockers

4. Excessive HR rise-> increase sympathetic drive or low fitness

Expected SBP response to exercise

1. Increase with intensity (~10mmHg per MET) due to increase HR and venous return

Expected DBP response to exercise

1. Stable or slight decrease

2. Peripheral resistance decreases with exercise

Expected MAP response to exercise

modest increase due to systolic pressure increase

Red flags for exercise

1. SBP fais to rise or drops with increased workload (not getting increase in CO, may not be regulating HR or SV

2. Excessive SBP rise (>250mmHg): Stop, acutely hypertensive

3. DBP increase > 10mmHG with exercise: increase after load, PR not accommodating

4. Delay HR recovery

Absolute indications to terminate exercise

1. Drop in SBP >/= 10 mmHg with increased workload and signs of ischemia

2. Moderate to severe angina: Ischemia of myocardium, insufficient coronary blood flow

3. Central nervous system symptoms (Cerebral blood flow): Dizziness, ataxia, near syncope

4. Signs of poor perfusion (ischemia outside the heart): Cyanosis, pallor

5. Sustained ventricular tachycardia (rise in ST segment): Indicated myocardial ischemia, not having ventricular repolarization

6. ST elevation (.1.0 mm) in leads without diagnostic Q waves

7. Technical difficulties: Inability to monitor ECG or BP

8. Subject requests to stop

Relative indications to terminate exercise

1. Drop in SBP >/= 10 mmHg without ischemic symptoms

2. Excessive BP response: SBP > 250 mmHg, DBP > 115 mmHg

3. Increasing chest pain

4. Fatigue, SOB, wheezing, leg cramps, claudication

5. Arrythmias: Increasing frequency or complexity

6. ST depression >/= 2.0 mm (another indication of ischemia)

7. Abnormal HR responses: Failure of HR to increase with workload

7. Hypertensive response: DBP rise > 10 mmHg during steady state exercise