Heart Failure

Question 1

What causes cardiac output to be inadequate in heart failure

Answer 1

Inadequate venous compromises stroke volume = PRELOAD
Excessive resistance compromises ejection volume = AFTERLOAD
Inadequate contractility can compromise SV = CONTRACTILITY

Question 2

What are the 4 categories of ejection fraction reduction

Answer 2

1. Normal (>55%)
2. Mildly reduced (45-54%)
3. Moderately reduced (30-44%)
4. Severely reduced (<30%)

Question 3

What is trans thoracic echocardiograms

Answer 3

Used to measure the ejection fraction

Question 4

Define heart failure

Answer 4

Heart failure is a clinical syndrome caused by the inability of the heart to supply blood to the tissues sufficient to meet their metabolic needs, or achieved at the expense of elevated filling pressures.

Question 5

Describe left heart failure

Answer 5

Dysfunction associated with the left ventricle
Ejection or filling issue
Blood backs up into the lungs causing congestion
Breathlessness, coughing, wheezing, respiratory symptoms, dizziness and cyanosis

Question 6

Describe right heart failure

Answer 6

Dysfunction associated with the right ventricle
Ejection or filling issue
Increased afterload of the pulmonary circulation
Often secondary to left heart failure due to congestion in the lung and pulmonary hypertension

Question 7

Compare chonic to acute heart failure

Answer 7

slow onset vs rapid onset
infection, pulmonary embolism, MI or surgery vs symptoms similar to chronic HF but timing of onset and worsening is much more severe
Chronic is more common

Question 8

Describe heart failure with reduced ejection fraction

Answer 8

Abnormal systolic function
Impaired contraction of the ventricles which despite an increase in heart rate results in decreased cardiac output
Typically, weakness is caused by damage or destruction of the ventricular myocytes
Weaker ejection leads to higher diastolic pressures
Systolic volume increases (so stroke volume and ejection fraction decreases)

Question 9

Describe heart filature with preserved ejection fraction

Answer 9

Abnormal diastolic function
Normal contraction of the ventricle
Increased stiffness of the ventricles causing impaired relaxation or impaired filling
End diastolic volume is reduced so reduced stroke volume is masked in ejection fraction

Question 10

Describe the aetiology of heart disease

Answer 10

Coronary heart disease
valve disease
Ischaemic heart disease 
MI
Hypertension 
Dilute cardiomyopathy 
Hypertrophic cardiomyopathy
aortic stenosis
restrictive cardiomyopathy

Question 11

Explain how valve disease causes heart disease

Answer 11

hardening of the valves reduces ventricular filling if AV or ejection if Semilunar

Question 12

Explain how ischaemic heart disease causes heart disease

Answer 12

Narrowing of the coronary arteries causes ischaemia in the heart muscle
Cardiac myocytes die

Question 13

Explain how myocardial infarction causes heart disease

Answer 13

Significant occlusion leading to death of heart muscle

Question 14

Explain how hypertension causes heart disease

Answer 14

Increases the afterload so ventricles work harder to pump blood, Hypertrophy inwards creates a reduced diastolic volume

Question 15

Explain how dilate cardiomyopathy causes heart disease

Answer 15

Dilated left ventricle (thin wall) reduces the generable pressure which reduces ejection.
Systolic dysfunction

Question 16

Explain how hypertrophic cardiomyopathy causes heart disease

Answer 16

Increases left ventricle thickness reduces the internal ventricular volume and impedes filling

Question 17

Describe the pathophysiology of heart disease

Answer 17

Damage to the myocardium
Morphological changes to the structure of the heart
Compensation mechanism includes tachycardia to maintain the cardiac output
Neurohormonal changes lead to augmentation of the renin-angiotensin system

Question 18

What are the symptoms of heart disease

Answer 18

Exertional breathlessness (LV HF)
Fatigue
Orthopnoea (breathlessness when lying down)
Paroxysmal nocturnal dyspnoea
Anorexia
Weight loss

Question 19

What are the signs of heart disease

Answer 19

Increased jugular venous pressure (increased pressure on the right so pressure backs up into the systematic veins)
Pitting oedema (RV HF)
Hepatomegaly
Ascites (fluid accumulates in the peritoneal cavity)
Tachycardia
Reduced pulse volume

Question 20

What lifestyle advice should be given to patients with heart disease

Answer 20

Weight loss
Stop smoking
Exercise
Less alcohol

Question 21

Give the progression of medication for heart failure

Answer 21

ACE inhibitor/angiotensin receptor blocker
Beta blocker
Spironolactone (diuretic)

Question 22

When is digoxin given

Answer 22

Normal rhythm + symptoms with ACE inhibitor and beta blocker

If AF is present

Question 23

Describe fluid control intervention for heart failure

Answer 23

Reducing ECF by removal of excess fluid
Haemofiltration
Peritoneal dialysis
Haemodialysis

Question 24

Describe the devices and surgery used in intervention for heart failure

Answer 24

Intra-aortic balloon pumping
ResynchronisationVAD/Total artificial heart

Coronary artery bypass graft
Valve surgery
Transplantation

Question 25

Explain how Law of LaPlace relates to heart failure

Answer 25

heart failure will increase wall stress due to dilation. The primary target of heart failure is to reduce the left ventricle wall stress

Question 26

Explain how reduced renal perfusion affects blood pressure

Answer 26

Activates the renin-angiotensin system, causing an increase in aldosterone.
Aldosterone increases blood pressure due to vasoconstriction, as well as an increase in sodium retention and therefore water retention.

Question 27

What is the gold standard for diagnosing heart failure

Answer 27

BNP: B-type Natriuretic peptide
>100pg/m indicates heart failure

Released from ventricular myocytes in response to stretch
Vasodilation
Inhibited renin and aldosterone secretion
Reduced sodium reabsorption