Cardiac changes Flashcards

1
Q

who should be excluced from the exercise part

A
Unstable angina 
Resting SBP>200mmHg or DBP >110mmHg
Uncontrolled tachycardia >120b.min-1 
Significant resting  ST segment depression
Uncontrolled atrial or ventricular arrhythmias 
Aortic stenosis 
Febrile illness 
Recent embolism 
Uncompensated congestive heart failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why does SV increase in healthy individuals following areobic training

A

↑ contractile function
↑ LV chamber volume (eccentric)
↑ LV muscle mass (concentric)
↑ in plasma volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why does contractile function increase

A

• ↑ calcium handling proteins in cell wall and SR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why does LV chamber volume increase

A

Myocyte elongation as sarcomeres added in series: occurs after 5 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

why does LV muscle mass increase

A

More myocytes added in parallel (hypertrophy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

why does plasma volume increase

A

10% PV expansion may occur in just 10 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

la place’s law

A

T = ( P * R ) / M
• Where T is the tension in the walls • P is the pressure difference across the wall • R is the radius of the cylinder • M is the thickness of the wall
To keep wall tension the same, the radius and the wall thickness must be proportional

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what alters myocradial oxygen consumption

A

tennison development
myocardial contractility
heart rate

  • wall tension is an imporatant determinant of MVO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what causes growth

A
NE and Epinephrine
Renin-angiotensin-aldosterone
GH and IGF
Thyroid hormones
mechanical stress
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

effect of NE and Epinephrine

A

Growth

stimulation of alpha and beta receptors in the myocardium cause cardiac growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

effect of Renin-angiotensin-aldosterone

A

Growth
– ↑ SNS activity reduces renal blood flow during exercise, ↑ renin release, thus ↑ RAA levels
– ↑ RAA levels stimulate cardiac myocytes to hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

effect of GH and IGF:

A

Growth
Cardiac myocytes have receptors for both GH and IGF
– Stretching of heart muscle is trigger for these hormones to activate gene expression
– IGF increases myofilament sensitivity to Ca++ thus ↑ contractile forc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the effect of thyroid hormones

A

Growth
Exercise stimulates TSH, thus thyroxin production
Thyroxin causes myocyte hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

effect of mechanical stress

A

Pressure overload = ↑ resistance = hypertrophy through ↑ cross sectional area (Concentric)
↑ volume overload = hypertrophy through ↑ myocyte lengthening (Eccentric)
Mechano-sensors in myocyte activated by stress:
– Surface receptors (integrins) and stretch activated ion channels ↑ CA++ influx → activate protein kinase pathways → hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Physiological adapltaions to areobic training in healthy individuals

A

imporved contractility

Angiogensis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

effect of imporved contracitility

A

Improved % shortening, time to peak shortening, relaxation time – ↑ calcium binding sites in myocytes – ↑ Na+ - Ca++ exchanger pumps speed removal of Ca back into SR – ↑ Ca stored in SR = more Ca = more contractile force – ↑ Ca sensitivity of myofilaments • Increased ATPase expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

effect of Angiogensis

A

Myocyte hypertrophy comes with angiogensis to increase blood flow • Increased arterial size to be equal or greater than increase in cardiac mass (over adaptation!) • Increased capillarisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

adaptaions to areobic training cardiovascular

Stroke volume

A
↑ Stroke volume 0 - 18% 
– ↑ blood volume 6-10% 
– Myocardial hypertrophy 
– Improved contractile force - ↓ ESV 
– ↑ ejection fraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

adaptaions to areobic training cardiovascular

parasympathetic tone

A

increased parasympathetic tone
• ↑ Heart rate variability
• Slower heart rate, thus more filling time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

adaptaions to areobic training cardiovascular

A
↑ SV 
↑ parasympathetic tone
↑ coronary collaterals 
↑ in cardiac capillary and arteriole blood flow 
↓ blood viscosity
↓ endothelial dysfunction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why does endothelial dysfunction reduce

A

Improved NO production promotes vasodilation

• Improved production of superoxide dismutase which mops up Reactive Oxygen Species (ROS stops NO working)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

adaptaions to areobic training cardiovascular during exercise

A

↑ in max SV
↓ In sub-maximal exercise heart rate - but this may arise without increase in SV
↓ Systolic blood pressure response
↑ Nitric oxide production, ↑ vasodilation thus ↓ TPR
↓ In myocardial oxygen demand (measured by RPP)
Small ↓ in Submax exercise Q
Improvement in max cardiac output
↑ Arteriovenous difference - more O2 extracte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

adaptaions to muscle from areobic training cardiovascular

A

↑ Arteriovenous difference
- V. important as may cause ↑ in peak VO2 without ↑ in Q.
↑ Mitochondrial number and quantity of aerobic enzymes
Shift towards a more aerobic muscle fibre type profile
↓ submaximal exercise muscle blood flow because of ↑ usage of delivered O2
↑ Maximal muscle blood flow
↑ Muscle capillary density
↑ Muscle fibre recruitment
↓ Blood lactate concentration during sub-maximal exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

effect of 1 MET increase

A

15% better surival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

effect of aerobic training on total exercise capacity

A

18-35% increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

effect of aerobic training on angina threshold

A

10-20% increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

activity during first 48hrs following MI/surgery

A

Self Care Activities
Arm and leg range of motion movement
Low Resistance activities
Minimal activities - active remodelling of myocardium occurring. Don’t want to exacerbate damaged area

28
Q

what should the patinet have knowledge of before dischange

A

Activities that are inappropriate or excessive
a safe progressive plan of exercise
optimal risk reduction

29
Q

why should they do activity post discharge

A

Physiological benefits
Increase physical self confidence
Decrease dependency on others

30
Q

rules of walking psot discharge

A
Walk at a comfortable pace (RHR + 20bpm) 
Take GTN spray 
Know rules of chest pain 
Choose flat route 
Go with someone at first 
Once solo, let others know the route
31
Q

post discharge walking week 1

A

1/4 mile

4 days

32
Q

post discharge walking week 2

A

1/2 mile

4 days

33
Q

post discharge walking week 3

A

3/4 mile

4-5 days

34
Q

post discharge walking week 4

A

3/4 mile

4-5 days

35
Q

post discharge walking week 5 &6

A

1 mile

5 days

36
Q

postive end points of exercise stress test

A
Reaching estimated max HR ± 10bts.min-1 
Light headedness, confusion, ataxia, cyanosis, dysponea, nausea 
Onset of moderate – severe angina 
Symptomatic SVT 
ST depression >2mm 
ST elevation >1mm 
VT 
Exercise induced LBBB 
Onset of 2nd or 3rd degree heart block 
Hypotension (>10mmHg drop in BP) 
Hypertension (>220 mmHg SBP : >110mmHg DBP) 
Inappropriate bradycardia (drop in HR >10 beats / min) with increase or no change in work load
37
Q

sensivity of exercise stress test

A

Sensitivity and specificity of stress test for diagnosis of CAD approx. 70%
The above may be better / worse due to expertise / equipment / population

38
Q

what is sensitivty

A

Sensitivity = % with disease who have abnormal results (test picks up something is wrong here!)

39
Q

what is specificity

A

% without disease who have normal results (test picks out healthy by showing normal results)

40
Q

prescribing exercsie using HR

A

etermine peak HR from test data
The highest HR achieved before problems (Angina etc)
Calculate training heart rate zone: 40-80% of the peak HR value
use common sense

41
Q

exercise prescriptin hreat rate reserve

A

Heart rate reserve (HRR) may be used if no stress test data are available
– however if stress test HR data are available HRR can still be used
Allows calculation of training HR zone
Scope to increase HR (HRR = predicted max HR - resting HR) + resting HR
Suggested 40-80% HRR

42
Q

calculating peak HR

A

Healthy males = 208 – (0.7 x age)
Healthy women = 206 – (0.88 x age)
CAD patients = 164 – (0.72 x age)
β-blocked = 203-1.49(age)

43
Q

exercise prescrpition RPE

A

RPE may be used to set training exercise intensity
A scale to quantify how hard the patient feels he / she is working
Roughly 12-16
Habituation necessary

44
Q

effect of anti-arrythmics of HR, BP, ischemia and exercise

A

HR ↓ or↔
BP ↔
Ischemia↔
Exercise capacity ↑

45
Q

effect of anticoagulants on HR, BP, ischemia and exercise

A

HR ↔
BP ↔
Ischemia↔
Exercise capacity ↔

46
Q

effect of ACE inhibitors on HR, BP, ischemia and exercise

A

HR ↔
BP ↓
Ischemia↔
Exercise capacity ↔

47
Q

effect of antilipidepics on HR, BP, ischemia and exercise

A

HR ↔
BP ↔
Ischemia↔
Exercise capacity ↔

48
Q

effect of digoxin on HR, BP, ischemia and exercise

A

HR ↓
BP ↔
Ischemi - maybe st depression
Exercise capacity ↔ or ↑

49
Q

effect of beta blockers on HR, BP, ischemia and exercise

A

HR ↓
BP ↓
Ischemia ↓
Exercise capacity ↑ or ↓

50
Q

effect of calcium channel blockers on HR, BP, ischemia and exercise

A

HR ↓
BP ↓
Ischemia↓
Exercise capacity ↑

51
Q

effect of nitrates on HR, BP, ischemia and exercise

A

HR ↑
BP ↓
Ischemia ↓
Exercise capacity ↑

52
Q

effect of diureactics on HR, BP, ischemia and exercise

A

HR ↔
BP ↓
Ischemia↔
Exercise capacity ↔

53
Q

describe the effect of digoxin

A

May decrease exercise HR • Improve exercise capacity in patients with atrial fibrillation or chronic heart failure • May produce false-positive results on the ECG, or ST segment depression in patients without coronary artery disease or ischemia. Use should be stopped 10 to 14 days prior to exercise test if possible

54
Q

describe the efefct of beat blockers

A

Addition or change in dosage of beta-blocker will require a new graded exercise test • Relationship between %VO2 and %HRR is not altered; therefore, usual methods to calculate THR for exercise prescription are still acceptable • HRmax and training HR will be lower in persons receiving beta-blockers

55
Q

describe the effect of calcium channel blockers

A

May length PR interval – facilitates Ventricular filling • Meds change will alter exercise response so new max test may be needed

56
Q

describe the efects of nitrates

A

Increases angina threshold • Possible hypotension • Longer cool down to avoid post-exercise hypotension

57
Q

describe the role of diuretcis

A

Diuretics may lower potassium levels (Hypokalaemia) – leads to PVC’s
Possible hypovolemia – will lower BP, Q and capacity – so check hydration status

58
Q

walk as exercise

A

lesuire or CV

Walking speed should achieve HR in training zone Pleasurable

59
Q

Golf as exercise

A
METS 4-7 
Aerobic / anaerobic 
Flat course 
9 Holes at first, ↑ number slowly 
3/4 swing 
Half set of clubs 
Pull or carry clubs 
Chest pain rules
60
Q

Bowls as exercise

A

Bowls has NO cardiovascular benefit

But will improve coordination, flexibility and confidence in physical activity

61
Q

Swimming as exercise

A
No swimming until sure of arrhythmia / angina /  wound status 
METS 4 - 8 
Is HR in training zone? 
Vary stroke
Chest pain rules 
Cold water
62
Q

who is strength training not appropriate for

A
Congestive Heart Failure 
Severe Valvular Disease 
Low ejection fractions 
Uncontrolled Arrhythmias 
Significant left ventricular dysfunction
63
Q

blood pressure response during resistance training

A
↑ intra muscular pressure
↓ muscular blood flow
↑intrathoaracic pressure
↓ Venous return
↓ → Q ↑ ↑TPR
= ↑BP
64
Q

acute effects of resistnce training

A
↑ BP ⇒ ↑ RPP (HR X SBP∴MVO2) not problematic if < 80% 1RM
↑ HR 60-80% 
HR max during circuit weights 
↑ VO2 30-50% 
VO2max during circuit weights
65
Q

what does strength training response depend on

A
Type (isotonic / isometric) 
Weight lifted (% 1RM) 
Duration of rest intervals 
Starting CV fitness of person 
Medications
66
Q

chronic eefcts of strength training

A
Muscular strength ↑ 20-30% in cardiac patients 
↑ efficiency of movement 
Small ↑ in peak VO2 
Improved blood lipid profile ?
 Improvement in body composition ? 
Reduction in BP
67
Q

when should you use resistnce training

A

Start 4-6 weeks into supervised cardiorespiratory endurance exercise program
into supervised cardiorespiratory endurance exercise program
Use elastic bands, light handweights, or resistive tubing to add variety
Monitor heart rate and ECG continually