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Flashcards in Heart Failure Deck (54):
1

ventricular stroke volume is dependent on which three factors

preload
afterload
contractility

2

how is preload approximated

by measuring ventricular end-diastolic volume

3

what is preload

ventricular wall tension at the end of DIASTOLE

4

what is afterload

ventricular wall tension during SYSTOLE

5

how is afterload approximated

systolic arterial/ventricular pressure

6

what is ventricular end-systolic volume dependant on/

afterload and contractility but not preload

7

how is ventricular wall stress estimated and what is its relationship to wall thickness and chamber radius

Laplace's relationship
wall tension is proportional to radius and inversely proportional to wall thickness

8

besides the side of heart failure, heart failure can be divided into two categories. Name them and briefly describe them

PRESERVED ejection fraction or DIASTOLIC dysfunction- abnormality in ventricular filling

REDUCED ejection fraction or SYSTOLIC dysfunction - an abnormality in ventricular filling from impaired contractility or increased afterload

9

name 5 conditions which impair ventricular filling

conditions which impair early diastolic relaxation (as this is an active process) or increase the stiffness of the ventricular wall
1. left ventricular hypertrophy
2. restrictive cardiomyopathy
3. transient myocardial ischaemia
4. myofibrosis
5. pericardial constriction or tamponade

10

name three things which impair contractility of the ventricles

coronary artery disease (MI/transient ischaemia)
chronic volume overload (mitral or aortic regurg)
dilated cardiomyopathies

11

name two conditions which can increase afterload in heart failure

aortic stenosis
uncontrolled HTN

12

describe two conditions which are non-cardiac in origin which cause heart failure

inadequate perfusion (severe haemorrhage)

increased metabolic demand (hyperthyroid)

13

outline three pathophysiological processes which occur in cardiac muscle leading to decrease in contractility

- change in gene expression (from adult to foetal)
- less efficient energetics
- impaired calcium handling (impair calcium release --> systolic dysfunction; impaired pumping of calcium outside of the cell impairs relaxation)

14

name three mechanisms of heart failure compensation

the Frank-Starling mechanism
neurohormonal adaptations
ventricular hypertrophy and remodelling

all of these mechanisms eventually become maladaptive

15

how does the Frank-Starling compensatory mechanism restore cardiac output

reduced stroke volume leads to incomplete ventricular emptying
on the next cardiac cycle this means the diastolic volume is increased.
This means that there is an increased stretch in the heart muscle and therefore increased contraction

16

which three neurohumoral alterations help compensate heart failure

1. the adrenergic nervous system
2. RAAS
3. incr production of ADH

17

what are the three immediate effects from activation of the sympathetic nervous system in the context of heart failure compensation

increased contractility
increased heart rate
increased vasoconstriction (via alpha receptors in arteries and veins)

18

how does venous vasoconstriction increase cardiac output

it increases the venous return to the heart (increasing preload) which leads to increased stroke volume

19

what are the stimuli for renin release from the juxtaglomerular cells in the kidney in heart failure patients

1) decreased renal perfusion following reduced CO
2) decreased salt delivery to macula densa
3) direct stimulation of beta-2 receptors in juxtaglomerular apparatus via the sympathetic nervous system

20

name two ways angiotensin II increases the intravascular volume

1) at the hypothalamus it stimulates thirst
2) increases aldosterone secretion at the adrenal cortex

21

when is BNP released

it is not normally detected but is released when the ventricular myocardium undergoes haemodynamic stress

22

what is endothelin-1 and what is its significance in heart failure

a potent vasoconstrictor from endothelial cells

in heart failure endothelin-1 levels correlate with adverse outcomes

23

how does chronic volume overload alter the ventricular musculature

it results in ECCENTRIC hypertrophy - addition of new sarcomeres in series

this impairs filling as the wall become stiffer

24

how does chronic pressure overload alter the ventricular musculature

it results in CONCENTRIC hypertrophy - addition of new sarcomeres in parallel

this alters the wall tension owing the Laplaces law as the ventricle becomes thicker

25

what causes constant fatigue in heart failure

mishandling of calcium in skeletal muscle

26

list some factors which precipitate symptoms in patients with chronic compensated heart failure

increased metabolic demand (fever, infection, anaemia, tachycardia, hyperthyroidism, pregnancy)

increased circulating volume (XS Na, XS fluid administration, renal failure)

Increased afterload (HTN, AS, PE)

impaired contractility (negative ionotropic medications, MI, ethanol ingestion)

medication non-compliance

Bradycardia

27

list some of the symptoms of left sided heart failure

dyspnoea
orthopnoea
paroxysmal nocturnal dyspnoea
fatigue

28

list some of the symptoms of right sided heart failure

peripheral oedema
RUQ discomfort from hepatomegaly

29

how might aortic regurg develop in heart failure

from cardiomegaly distorting the valve orifice but the valve leaflets remain unchanged

30

what is the first symptom of pulmonary oedema

paroxysmal nocturnal dyspnoea- respiratory chemoreceptors are less responsive during sleep

31

at which pulmonary pressure can transudation of fluid into the pulmonary interstitium occur

20mmHg

32

what is PND

severe breathlessness which awakens the patietn from sleep 2-3 hours after going to bed

33

how does haemoptysis occur in heart failure

from engorged bronchial veins

34

what causes anorexia in heart failure

oedema in the gastrointestinal tract

35

what are the clinical signs of left sided heart failure

diaphoresis (sweating)
tachycardia and tachypnoea
pulmonary rales
loud P2
S3/4 gallop

36

which gallop rhythm is associated with systolic dysfunction

S3 gallop (early diastolic sound) caused by abnormal filling of a dilated chamber

37

which gallop rhythm is associated with diastolic dysfunction

S4 gallop (late diastolic sound) cuased by forceful atrial contraction into a stiff ventricle

38

which type of diuertic would be used immediately in acute heart failure

loop as they have a strong effect and quicker onset

they work by inhibiting reabsorption from the loop of Henle

39

how do thiazide diuretics work

inhibit Na reabsorption in the DCT

40

what are the side effects of thiazide (and related diuretics)

electrolyte disturbance (decr Na and K)
Gout (incr urate)
Hyperglycaemia
Derranged lipids

41

how does nitroglycerine work in the treatment of acute heart failure

reduces preload, afterload and increases stroke volume

42

what are the commonest causes of heart failure

IHD
HTN
valve disease
Cardiomyopathy

43

what is cardiac cachexia

weightloss and anorexia commonly seen in HF

Caused by metabolic changes, gut congestion, reduced intake, inflammation

is a predictor of survival

44

which heart sound is pathognomonic of heart failure

gallop rhythm

45

What is Osler-Weber-Rendu disease also known as and what does it cause

hereditary haemorrhagic telangiectasia

there is vascular dysplasia and AVMs in the lungs liver and CNS

46

what are the main differential diagnoses for heart failure

liver disease
nephrotic syndrome

47

what is Eisenmenger's syndrome

left to right shunt causing pulmonary hypertension leading to a cyanotic heart defect

48

which two drugs used in the treatment of heart failure can cause gynaecomastia

spironolactone
digoxin

49

which is the only ACEI used in paediatric cardiology

Captopril

50

which protein is lacking in hereditary angioedema and why is this relevant to heart failure

C1esterase inhibitor is lacking

can't tolerate ACEI or ARBs

51

Kerley's B lines are a specific sign of what

pulmonary oedema
can be caused by anything causing lymphatic obstruction eg sarcoidosis

52

what is the bat wing appearance

a sign of pulmonary oedema on CXR

53

would what a giant v-wave on jugular venous pressure be suggestive of

tricuspid regurgitation

54

what would cannon a-waves in a jugular venous pressure be suggestive of

complete heart block