Heart failure Aetiology and Pathophysiology

Question 1

Definition of CO?

Answer 1

The amount of blood the heart pumps in 1 minute (CO= SV xHR)

Question 2

Definition of SV?

Answer 2

Volume of blood pumped out of the heart with each cardiac contraction.

Question 3

Definition of ejection fraction?

Answer 3

The proportion of blood ejected with each heart beat compared with what’s in the ventricle when its completely full

Question 4

Normal value of ejection fraction?

Answer 4

50-70%

Question 5

Equation for ejection fraction (EF)?

Answer 5

EF= SV/EDV x 100

Question 6

Definition of heart failure?

Answer 6

Complex clinical syndrome in which the heart is incapable of maintaining a CO adequate to accommodate metabolic requirements and the venous return.

Question 7

What is chronic heart failure?

Answer 7

Long term, gradual, reduction in heart function

Question 8

What is acute heart failure?

Answer 8

Sudden decompensation in heart function (leaky valves, MI, papillary muscle ruptures, embolism).

Question 9

What is HRrEF?

Answer 9

Heart failure with a reduced EF (systolic dysfunction).

Question 10

What is HFpEF?

Answer 10

Heart failure with a preserved EF (diastolic dysfunction).

Question 11

What is diastolic HF?

Answer 11

Able to contract but not able to fill properly (walls are thickened and stiff).

Question 12

What is systolic HF?

Answer 12

Big, baggy hearts, not squeezing to eject the blood properly (walls are thin and dilated).

Question 13

What is the prevalence of HF by age and gender?

Answer 13

Higher for males until women go through menopause, then evens out.

Question 14

Aetiology of HF?

Answer 14

-Ischaemic heart disease
-hypertension
-idiopathic cardiomyopathy
-infections
-toxins
-valvular disease
-prolonged arrhythmias

Question 15

What is Class 1 of HF (New York heart association classification)?

Answer 15

No symptoms with ordinary activity.

Question 16

What is Class 2 of HF?

Answer 16

Slight limitation of physical activity. Comfortable at rest but ordinary physical activity results in fatigue, palps, dyspnea, angina.

Question 17

Class 3 of HF?

Answer 17

Marked limitation of physical acitivity. Comfortable at rest, but less than ordinary physical activity results in fatigue, palps, dyspnea.

Question 18

Class 4 of HF?

Answer 18

Unable to carry out any physical activity without discomfort (uncomfortable at rest).

Question 19

Stage A of HF?

Answer 19

High risk: hypertension, coronary artery disease, diabetes, family history of cardiomyopathy.

Question 20

Stage B of HF?

Answer 20

Asymptomatic LVD: previous MI, LV systolic dysfunction, asymptomatic valvular disease.

Question 21

Stage C of HF?

Answer 21

Symptomatic HF: Known structural heart disease, shortness of breath and fatigue, reduced exercise tolerance.

Question 22

Stage D of HF?

Answer 22

Refractory End stage HF: Marked symptoms at rest despite maximal medical therapy.

Question 23

Frank- Starling curve?

Answer 23

the higher stretch, higher SV (in HF, exceeds the stretch, becomes baggy therefore HF).

Question 24

What factors impact SV?

Answer 24

Preload (amount of stretch), contractility, after load (pressure it has to overcome).

Question 25

When is after load increased?

Answer 25

In stenosis and vasoconstriction.

Question 26

Symptoms of LV dysfunction?

Answer 26

-dyspnea on exertion -paroxysmal nocturnal dyspnea -tachycardia -cough -haemoptysis -fatigue

Question 27

Physical signs of LV dysfunction?

Answer 27

-basilar rales (crackles in lungs) -pulmonary oedema -S3 gallop (ectopic beat) -pleural effusion -Cheynes- stokes resp (lots of fast breathing)

Question 28

Symptoms of RV failure?

Answer 28

-abdominal pain -anorexia -nausea -bloating -swelling

Question 29

Physical signs of RV failure?

Answer 29

-peripheral oedema -jugular venous distention (JVP) -abdominal- jugular reflex -heptomeglay (liver enlargement)

Question 30

equation for Mean arterial pressure (BP)?

Answer 30

BP= CO x TPV

Question 31

How does the sympathetic NS maintain normal CV homeostasis?

Answer 31

Increases contractility, tachycardia, vasoconstriction (increases HR and SV and TPV and therefore, increases BP)

Question 32

How does the RAAS system maintain CV homeostasis?

Answer 32

Angiotensin II is a vasoconstrictor, sodium and water retention, LV remodelling and vascular remodelling.

Question 33

How does vasopressin (ADH) maintain CV homeostasis?

Answer 33

When central baroreceptors sense decrease in BP, stimulate hypothalamus which produces vasopressin (ADH) for release by pituitary gland which causes vasoconstriction and Bp is increased.

Question 34

What is the compensatory mechanism of ventricular remodelling?

Answer 34

Alterations in hearts shape and size, structure and function brought about by the chronic hemodynamic stresses experienced by failing heart (eg ventricle dilates and loses twisting and squeezing force).

Question 35

What are the 3 types of natriuretic peptides?

Answer 35

-atrial natriuretic peptide (ANP)- found in atria -brain natriuretic peptide (BNP) -C-type natriuretic peptide (CNP)- found in central NS

Question 36

What is the point of BNPs?

Answer 36

Used as a marker to detect, diagnose and monitor HF severity.

Question 37

Effects of salt and water retention?

Answer 37

Augments preload, leads to pulmonary congestion and anasarca.

Question 38

What is anasarca?

Answer 38

Congestion all over the body.

Question 39

Effects of vasoconstriction?

Answer 39

Maintains BP for perfusion of vital organs, however, leads to excessive after load.

Question 40

Effects of Sympathetic stimulation?

Answer 40

Increased HR and EF, Increases energy expenditure