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Flashcards in deck_835165 Deck (49):
1

Define heart failure

A state in which the heart fails to maintain an adequate circulation for the needs of the body despite an adequate filling pressure

2

Give some chronic causes of L heart failure

Systemic hypertensionArrhythmiasCoarctation of the aortaAnaemiaThyrotoxicosisIschaemic heart disease

3

Give some chronic causes of R heart failure

Pulmonary hypertension Arrhythmias Chronic lung diseaseChronic pulmonary/tricuspid valve dysfunctionLeft to right shuntLeft heart failure

4

Give some acute causes of R heart failure

Pulmonary embolism Rupture of tricuspid valve cusp

5

Give some acute causes of L heart failure

Myocardial infarctionRupture of mitral or aortic valve

6

What are some causes on congestive heart failure?

ThyrotoxicosisLesions of the aortic and mitral valvesAnaemia

7

What are the 6 compensatory mechanisms for heart failure?

SNS activationRAAS activationAnti-diuretic hormonesNitric-oxideProstaglandin E2 and I2 Hypertrophy of cardiac muscle

8

How is the sympathetic nervous system activated?

Falls in BP and blood volume are detected by baroreceptors in the aortic arch and carotid sinus

9

What does the SNS do to compensate in heart failure?

Increased HR and force of contraction --> increase cardiac output and then increasing the work load of the heartSecretes renin to activate RAAS

10

What does vasoconstriction of the arterioles of?

increases the blood pressure and the after load

11

How can left heart failure cause right heart failure?

Left heart failure raises pulmonary arterial pressure which the causes right heart failure

12

What is the name used when both ventricles are affected in heart failure?

Congestive heart failure

13

Why are the sympathetic nervous system and the renin-angiotensin-aldosterone-system activated in heart failure?What affect do they have?

To maintain cardiac outputThey cause the struggling heart to work harder

14

How if the RAAS activated?

Caused by reduced blood flow to the kidneys and SNS causing renin secretion. Causes endothelin secretion by vascular endothelial cells. Leads to renal vasoconstriction which activates RAAS

15

What does the RAAS do?

Angiotensin is converted to angiotensin 1 by renin. Angiotensin 1 is converted to angiotensin 2 by angiotensin converting enzyme. Angiotensin 2 promotes vasoconstriction and aldosterone release from the adrenal cortex.

16

What effects does aldosterone have?

Increases BP, NA and H2O retention by the kidneys causing and increase in blood volume, increasing venous return and stroke volume.

17

Why are diuretics used in heart failure?

You want to prevent water retention and increased blood volume in order to limit oedema

18

When does peripheral oedema occur?

Due to right-sided heart failure. Failure to pump correctly causes and increase in venous pressure and capillary pressure, forcing fluid out into the tissues.

19

When does pulmonary oedema occur?

Due to left-sided heart failure. Causes an increased left-atrial pressure which also causes a rise in pressure of the vessels in the pulmonary circulation. (Also increases pulmonary artery pressure due to low resistance of these vessels)

20

Define systolic dysfunction

The impaired ability of the heart to contract

21

Define diastolic dysfunction

Impairment of the filling of the heart.

22

What does heart failure cause?

Systolic dysfunctionDiastolic dysfunctionIncreases ADH secretionInhibits nitric oxide secretion

23

What causes heart failure?

Ischaemic heart disease is the most common cause of heart failure-- myocardial infarction, valve rupture, hypertension (pulmonary and systemic), congenital heart diseases, anaemia, chronic lung disease

24

What can happen to the heart muscle itself to compensate in heart failure?

Hypertrophy of cardiac muscle causes a decreased ventricular volume which worsens the decreased cardiac output causing the heart to remodel and dilate.

25

What are the signs and symptoms of left heart failure?

Fatigue (C output doesn't meet needs)Exertional dyspnoea (cant meet increased demand)Pulmonary oedema (increased venous pressure ...)Displaced apex beat and cardiomegaly (due to LV hypertrophy)Tachycardia (sympathetic response to decreased CO)

26

Give some characteristics of pulmonary oedema

Increased venous pressure --> increased hydrostatic pressure in capillaries --> fluid moves into tissuePULMONARY CRACKLES: fluid collects in the bottom of the lungs when uprightORTHOPNOEA: fluid distributes when lying down, causing BREATHLESSNESS from impaired gas exchangeCYANOSIS: impaired gas exchanges leads to hypoxaemia

27

Why is fatigue presents in right heart failure?

Decreased flow to the lungs results in hypoxaemia due to a ventilation/perfusion mismatch. Insufficient oxygen for metabolic needs.

28

Why is breathlessness present in right heart failure?

Decreased oxygenated blood enters systemic circulation. Hyperventilation results in order to increase the partial pressure of oxygen.

29

What causes raised jugular venous pressure?

Failure of right side of the heart to pump in right heart failure causes a rise in venous pressure and distension of the jugular veins.

30

What is pitting oedema and why does it occur?

Oedema that when you press down on, leaves and indentation in the skin. It is due to increased venous pressure --> increased hydrostatic pressure in capillaries --> fluid leaks out into the interstitium

31

Why does hepatomegaly occur in right heart failure?

Bloods backs up into inf. vena cava causing congestion of the hepatic veins --> hepatic engorgement.

32

What areas in the body are targeted fro drugs to help regulate the cardiac output?

KIDNEYS: regulate blood volume (Na and H20 reabsorption)ARTERIOLES: regulate blood pressureMYOCARDIUM: regulates force of contraction (depends on degree of stretch)SAN: regulates heart rate

33

What are the main changes that are made in order to manage heart failure?

Lifestyle -- diet, exerciseDrugs if lifestyle changes have been changed and are having little/need more of an effect1. antihypertensives2. beta-blockers to reduce cardiac workload3. positive inotropes4. anti-arrhythmic drugs

34

Name some anti-hypertensive drugs

alpha-1 antagonistsDiuretics e.g. loop diuretics & spironolactoneACE-inhibitors

35

What happens in right heart failure?

Right heart does not work properly and leads to an increased venous pressure causing oedema due to increased venous pressure increasing the hydrostatic pressure in the capillaries.

36

What is nocturia and why does it occur?

Frequent urination throughout the night. Due to fluid which has been built up in ankles/legs returns to the blood stream when lying down

37

What are the characteristic signs of right heart failure?

Pitting peripheral oedemaRaised jugular venous pressureFatigueHepatomegalyBreathlessnessAscites

38

Generally, what does left heart failure have an effect on?

Lung function

39

Generally, what does right heart failure have effects upon?

Differing areas in the systemic circulation

40

What tends to me the main cause of right heart failure?

Tends to be secondary to left heart failure

41

What are some common signs of left heart failure?

Increased breathing rate (tachypnea) and increased work of breathing

42

When does cyanosis occur in left heart failure?

It is quite rare as it is a late sign of severe pulmonary oedema

43

What are the main causes of congestive heart failure?

Ischaemic heart diseaseCigarette smokingHypertensionObesity DiabetesValvular heart disease (usually older populations)

44

How is the severity of heart failure determined and how are they differentiated?

Heart failure is divided into classes depending on the the impact on life and physical exertionClass 1 = lowest severityClass 4 = more severe

45

Describe the different classifications of heart failure

Class 1 = No symptomatic limitation of physical activityClass 2 = Slight limitation of physical activity with ordinary physical activity resulting in symptoms. Have no symptoms at restClass 3 = Marked limitation of physical activity with less than ordinary activity causing symptomsClass 4 = Unable to carry out physical activity without symptoms and may have symptoms at rest. Increased discomfort with any kind of physical activity

46

What stimulates renin release from the kidneys?What does renin do?

Drop in blood pressureCatalyses conversion of angiotensin to angiotensin 1

47

What effects does the sympathetic nervous system have on blood vessels?

Activates the alpha-1 receptor which causes vasoconstriction of blood vessels, increasing blood pressure which increase the after-load and the preload of the heart therefore increasing the whole workload of the heart Also affects beta-1 receptors in order to increase the chronotropy and inotrophy of the heart

48

What affect do ACE inhibitors have?

Prevents conversion of angiotensin 1 to angiotensin 2. Has an indirect vasodilatory and diuretic effect, which decrease the workload on the heart.

49

Why can increasing the action of the RAAS be detrimental?

Angiotensin 2 has a number of effects on certain organsIncreases atherosclerosis, vasoconstriction, vascular hypertrophy, endothelial dysfunction --> STROKE and HYPERTENSION LV hypertrophy, fibrosis and apoptosis in the heart --> MICan cause GFR, Proteinuria, Aldosterone release and glomerular sclerosis which can lead to RENAL FAILURE