Heart Failure

Question 1

The closure of which valves cause the first heart sound, S1?

Answer 1

Mitral and tricuspid

Question 2

The closure of which valves cause the second heart sound, S2?

Answer 2

Aortic and pulmonary

Question 3

What is systole?

Answer 3

When the ventricles contract and push blood from ventricles into circulation

Question 4

What is diastole?

Answer 4

When the ventricles relax and fill with blood

Question 5

What is heart failure?

Answer 5

A syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the heart to function as a pump to support a physiological circulation

Question 6

Describe the cardiac cycle

Answer 6

Right side:
vena cava –> RA –> tricuspid valve –> RV –> pulmonary valve –> pulmonary trunk –> pulmonary arteries –> lungs

Left side:
pulmonary veins –> LA –> mitral valve –> LV –> aortic valve –> aorta

Question 7

What is stroke volume?

Answer 7

The volume ejected by a ventricle

Question 8

What is preload?

Answer 8

The degree of stretch in the ventricles at the end of diastole

Question 9

What is end-diastolic volume?

Answer 9

The blood in a ventricle at the end of diastole

Question 10

What is end-diastolic pressure?

Answer 10

The pressure in the LV following the completion of diastolic filling

Question 11

What is preload proportional to?

Answer 11

Stroke volume

Question 12

What is afterload?

Answer 12

The pressure needed to be overcome in order to pump blood from the ventricle into the circulation

Question 13

What can cause afterload to be higher?

Answer 13

Hypertension
Stenosis of the aortic valve

Question 14

What can reduce afterload?

Answer 14

When the ventricular wall is thickened

Question 15

What is systolic heart failure, what does it usually affect and what can it be caused by?

Answer 15

When the ventricle can’t pump blood effectively during systole
Usually affects LV
Increased afterload, damaged muscle, hypertrophy

Question 16

What is diastolic heart failure?

Answer 16

When the heart chambers can’t fill with blood in diastole

Question 17

What is compliance?

Answer 17

How easy a chamber is to fill

Question 18

When can ventricular compliance be reduced?

Answer 18

Impaired ventricular relaxation
Hypertrophy

Question 19

What are some systemic causes of heart failure?

Answer 19

Anaemia
Sepsis
Hyperthyroidism
Liver failure
Excess fluid

Question 20

What is left ventricular failure and what can it then cause?

Answer 20

Persistently elevated ventricular pressure in LV
Pulmonary oedema and SOB (which is worse when lying down –> PND)

Question 21

What is right ventricular failure?

Answer 21

RV is not pumping as efficiently as it should be

Question 22

What is the most common cause of right-sided heart failure?

Answer 22

Left-sided heart failure
High pulmonary pressure from LV –> excessive afterload in RV –> works harder and fails

Question 23

Treatment of heart failure

Answer 23

Decreased cardiac output in heart failure is sensed by baroreceptors and kidneys –>
Stimulates RAAS –>
Increases pumping of heart and body retains fluid
This helps initially but ultimately increases afterload which causes more heart failure

Drugs try and remove these effects –> help the heart function or assist kidneys to remove excess fluid

Pacemaker or implantable defibrillator

Question 24

What is a heart murmur, what can they be caused by and what can they be in terms of timing?

Answer 24

Heard when blood flow through the heart is turbulent
Caused by stenosis (narrowing) or regurgitation (leaky valve)
Can be systolic or diastolic in timing

Question 25

What best describes the timing of a systolic murmur?

Answer 25

Between S1 and S2

Question 26

What best describes the timing of a diastolic murmur?

Answer 26

Between S2 and S1

Question 27

Describe how Starling's forces can lead to oedema in heart failure

Answer 27

In heart failure, pressure backs up in the venous system which then backs up into the capillaries, so hydrostatic pressure is greater than oncotic pressure --> fluid forced out into tissues causing oedema

Question 28

Name the 2 types of drugs which can be used to treat heart failure, how they can help heart failure and give some examples of each drug

Answer 28

ACEi - lisinopril, ramipril, captopril, enalapril Beta blockers - bisoprolol, carvedilol, nebivolol These drugs block the compensatory response to heart failure which improves symptoms

Question 29

Which drug can also treat heart failure by increasing the force of contraction?

Answer 29

Digoxin It has a positive inotrope effect which inhibits the Na+/K+ ATPase pump --> increased concentration of intracellular Ca --> more forceful contractions

Question 30

Which type of drugs can be used to relieve SOB?

Answer 30

Loop diuretics Furosemide, bumetanide, torasemide Reduces solute reabsorption in thick ascending limb of LoH Promotes urinary excretion of solutes and water