1. Cardiovascular System and Exercise

2. Cardiac Output
Amt. of blood pumped by heart in 1 -minute
HR x SV

3. Measuring Cardiac Output
Fick Method
Indicator Dilution
Thermal Dilution
CO2 Rebreathing

4. Direct Fick Method 02 consumption  spirometry Arterial blood  ABG
Mixed venous blood  catheter

5. Direct Fick Method

6. Direct Fick Method O2 consumption (mL/min) x 100
a-v O2 difference (mL/100 mL blood)
Advantages/Disadvantages

7. Indicator Dilution
Dye or radioactive solution injected into large vein
ABG
radioactive counter or photosensitve device

8. Indicator Dilution dye injected avg dye conc. in blood x duration
Advantages/Disadvantages

9. Thermal Dilution Catheter  Right Heart
Inject saline (temp. < blood)  RA
Measure temp. in PA
 temp / time

10. Thermal Dilution
 temp / time
Advantages/Disadvantages

11. CO2 Rebreathing Spirometry w/ rapid CO2 analyzer
breath by breath analysis
estimation of venous and arterial CO2 conc.

12. CO2 Rebreathing CO2 production x 100 v-a CO2 difference
Advantages/Disadvantages

13. Cardiac Rest

14. Immediate Response to Exercise
 CO 20  HR and  SV
HR (later) SV
CO  linearly and directly w/ exercise intensity

15. Immediate Response to Exercise

16. Stroke Volume
Starling mechanism
 ventricular contractility

17. Cardiac Output during Maxium Exercise

18. Training Effect on Cardiac Output
 SV during rest & exercise
Maximum SV: 40-50% VO2max (60-66% HR max)
 SV is > from rest  exercise

19. Factors Affecting Stroke Volume
Diastolic filling
 venous return
 HR

20. Factors Affecting Stroke Volume
Systolic Emptying
preload
enhanced by catecholamines

21. Training Effects Ventricular enlarged chamber enhanced compliance
enlarged myocardium HR
 by 12 to 15 bpm

22. Final Comments on CO and SV
Stroke Volume Index
Cardiac Output Index

23. Blood Distribution @ Rest
5000 mL
(1000 ml)
(700 ml)
(1100 ml)
(300 ml)
(700 ml)
(1350 ml)

24. Blood Distribution during Exercise
25000 mL
1000 ml
21,000 ml
600 ml
900 ml
500 ml
250 ml

25. CO and Oxygen Rest arterial blood 200 ml O2/L pump 5 L/min
1000 mL O2/min available
uptake 250 ml O2/min
reserve 750 ml O2/min

26. CO and Oxygen Exercise arterial blood 200 ml O2/L pump 25 L/min
5000 mL O2/min available
 CO   available O2

27. Meeting O2 Demands of Exercise
 CO
 use of O2 carried by blood

28. O2 Uptake and Exercise

29. Athlete’s Heart Myocardial hypertrophy left ventricle
Resistance Training
 wall thickness /mass
<  cavity size
Endurance
 volume
<  wall thickness

30. Pathological Heart 20 HTN
Myocardial hypertrophy
left ventricle
distended
less compliant

31. Hypertension Systolic > 140 mmHg / Diastolic > 90 mmHg
25-33% of populations will have HTN
Prevalent in African Americans
Up to 95% of HTN is of unknown cause

32. Hypertension
Can result in:
Heart failure MI
CVA

33. Hypertension Rx: Diet Exercise Weight control Stress reduction
Medication

34. Endurance Exercise & BP
Systolic
   intensity 20  CO
120  200 ( )
Steady-state: may  20 arteriole dilation   TPR

35. Endurance Exercise & BP
Diastolic
little 
  15mmHg  abnormal  stop exercise/testing

36. Graded Exercise & BP

37. Long Term Effects of Aerobic Exercise
Training Effect:
Aerobic   6 –10 mm
Most effective in mild to moderate HTN
Mechanism:
 sympathetic activity
Altered renal function

38. Resistance Training & BP
Isometric (% MVC)
Free Weight Bench Press
Hydraulic Bench Press 25 50 75
100
Slow
Fast
Systolic
172
179
200
225
169
232
237
245
Diastolic
106
116
135
156
104
154
101
160

39. Resistance Training & BP
Muscle Contraction  compresses peripheral arteries ( to force)
> muscle mass  > BP
480/350 mmHg 20 valsalva

40. Resistance Training & BP
Mechanism:
 Sympathetic
 MAP (average pressure)
 Cardiac output
BP = CO x TPR

41. Resistance Training & BP
BP accommodates to regular resistance training blunted BP response to exercise

42. Recovery
Hypotensive response in recovery from sustained submaximal

43. Upper vs. Lower Body Exercise
Systolic (mm Hg)
Diastolic (mm Hg)
% of VO2max
Arms
Legs 25
150
132 90 70 40
165
138 93 71 50
175
144 96 73 75
205
160
103

44. Upper vs. Lower Body Exercise

45. Upper vs. Lower Extremity Exercise and BP Response
UE:
> BP response 20 smaller musculature & vasculature  > TPR
> BP response   Double Product (Rate Pressure Product)

46. Rate Pressure Product or Double Product
= SBP x HR
index of relative cardiac work
indicator of myocardial O2 uptake & coronary blood flow

47. Cardiovascular Regulation
Electrical Activity (intrinsic regulation)
S-A node  atria  A-V node  A-V bundle (Purkinje fibers)  ventricles

48. Extrinsic Regulation Sympathetic Catecholamines  HR and contractility
Adrenergic fibers (norepi)  constrict
Cholinergic fibers (acetylcholine)  dilatation in skeletal & cardiac muscle

49. Extrinsic Regulation Parasympathetic Acetylcholine  HR
No effect on contractility
Vagus nerves

50. Extrinsic Regulation Pre-exercise anticipation 
 sympathetic activity
 parasympathetic
Greatest  HR

51. Extrinsic Regulation Onset of exercise & low intensity 
 Parasympathetic
Exercise intensity    Sympathetic

52. Extrinsic Regulation
Central command provides greatest control of CV system
Pre-exercise anticipation
100% HR

53. Heart Rate Response to Exercise
180
Heart Rate (bpm)
120 60
start 88
176
264
352
440
Distance (yards)

54. Peripheral Input Receptors in muscle monitor mechanical and chemical
Exercise Pressor Reflex

55. Peripheral Input Receptors in arteries Baroreceptors
BP   sympathetic input
Mechanoreceptors
heart and large veins

56. Blood Distribution & Exercise
Blood is distributed as needed (autoregulated)
Rest - 1 of capillaries open in muscle
 tissue O2  vasodilation in skeletal & cardiac muscle