Lecture 7 - Cardiac Disorders

Question 1

HF definition

Answer 1

Inability of the heart to maintain enough CO to meet body needs

Question 2

Pathogenesis of HF

Answer 2

Structural or functional abnormalities impair ability of heart to contract, relax, or both

Question 3

Preload

Answer 3

Degree of stretch on heart muscle fibres just before contraction

Question 4

After load

Answer 4

Pressure the heart must work against to eject blood during systole

Question 5

Ejection fraction

Answer 5

% of blood teh heart pumps out each beat as a fraction of how much it filled iwth

Systolic vol/end diastolic vol = EF

Question 6

Systolic dysfunction is most commonly due to

Answer 6

IHD and valve diseases

Question 7

What is systolic dysfunction

Answer 7

Impaired contractility due to loss of cells, fibrosis, or reduced ATP production

Leads to a reduced ejection fraction

Question 8

Diastolic dysfunction is

Answer 8

Impaired myocardial relaxation du ego altered calcium handling or collagen deposition

Question 9

Ejection fraction in diastolic dysfunction

Answer 9

EF may be normal % wise, but the fill is less

If heart fills 50ml and ejects 35, EF = 70%

Question 10

Causes of diastolic dysfunction

Answer 10

Pericardium effusion, IHD, hypertrophic cardiomyopathy

Question 11

Compensatory mechanisms in HF

Answer 11

SNS
Increased preload
Myocardial hypertrophy

Help restore CO, harmful long term

Question 12

SNS compensatory mechanism

Answer 12

NE release -> increase HR and contractility

Venoconstriction -> increase venous return -> increases preload

RAA pathway activation -> increase blood volume

Question 13

Problems with SNS compensatory mechanism

Answer 13

Tachycardia increase o2 use

Cardiac remodeling

Increase after load due to higher SVR

Question 14

Increased preload compensatory mechanism initiated by (3)

Answer 14

Reduced EF, RAA activation, venoconstriction

Question 15

Frank starling curve

Answer 15

Graph that says increasing preload in HF is pointless because no matter how much you increase the preload, stroke volume caps out at about 50

Question 16

Problems with chronic increase of end diastolic pressure

Answer 16

Pulmonary congestion

Stretching of heart muscle increases o2 consumption

Question 17

Myocardial hypertrophy

Answer 17

Ventricles undergo hypertrophy in response to increased work/loss of myocytes
- slowest compensatory mechanism

2 types

Question 18

2 types of myocardial hypertrophy

Answer 18

Concentric

Eccentric

Question 19

Concentric myocardial hypertrophy

Answer 19

Occurs in response to increased pressure work

Heart requires more force to generate pressure

Sarcomeres are added in parallel (thick ass walls)

Question 20

Eccentric myocardial hypertrophy

Answer 20

Occurs in response to increased volume work

Pathways are forced open, sarcomeres form in series (line)

Stretched out walls

Question 21

Key point in myocardial hypertrophy

Answer 21

Remodeling makes ventricles weaker and eventually leads to decreased function

Question 22

Important factor in driving myocardial hypertrophy

Answer 22

Angiotensin 2

Blocking it can slow hypertrophy

Question 23

Which HF is more common

Answer 23

Left

Left often leads to right as well

Question 24

When ventricles fail, it caused forward and backward failures

Answer 24

Forward
- insufficient pumping and poor CO

Backward
- congestion of blood behind the pumping chamber

Question 25

Etiology of left sided HF

Answer 25

IHD, HTN, valve diseased, myocardial disease

Question 26

Backwards effect of left sided HF

Answer 26

Accumulation of blood within pulmonary circulation, pulmonary edema Caused dyspnea, orthopaedic (lying SOB), nocturnal dyspnea, cough, crackles, etc

Question 27

Forwards effect of left sided HF

Answer 27

Insufficient CO with low O2 and nutrient delivery to peripheral tissues and organs

Question 28

Complications of left sided HF

Answer 28

Increase left atrial pressure leads to atrial dilation Can cause AFIB, stasis and thrombosis

Question 29

Backward effects of left sided HF are all

Answer 29

Lung related

Question 30

Etiology of right sided HF

Answer 30

Most caused by left sided HF Isolated right sided failure mostly due to cor pulmonale

Question 31

Cor pulmonale + how to leads to right sided HF

Answer 31

It is a lung issue Pulmonary disorder = pulmonary HTN = high after load = RV hypertrophy = RV failure

Question 32

Backwards effects of right sided HF

Answer 32

Congestion in systemic circuit System is edema

Question 33

Forward effects of right sided HF

Answer 33

Low output to LV leading to low CO

Question 34

Nutmeg liver

Answer 34

Blood spots due to backup of blood stretching the capillaries in right sided HF

Question 35

HF s/s (acronym)

Answer 35

FACES (fatigue, activity limitation, congestion, edema, SOB)

Question 36

Diagnosis of HF includes

Answer 36

S/S Echocardiography (Chamber size/volume, EF, valve problems) Natriuretic peptide level - synthesized by ventricles in response to fluid overload

Question 37

B type natriuretic peptide levels indicate:

Answer 37

Released by ventricles when fluid vol is high

Question 38

Treatment of HF (goal, methods)

Answer 38

Goal to improve CO and minimize congestive symptoms and cardiac workload Reduce preload (diuretics, ACE) Improve contractility Reduce AG2 effects (drugs like ACE/ARBS) Implantable defibrillators Surgery (Valve replacement)