Heart Failure

Question 1

Label the parts of the heart on the diagram

Answer 1

Question 2

Why does tricuspid valve regurgitation cause venous congestion?

Answer 2

The tricuspid valve normally allows the unidirectional flow of venous blood from the right atrium into the right ventricle.

If it is damaged, when the right ventricle contracts, blood will be regurgitated back into the right atrium and back into the SVC and IVC and into the venous system. These veins are valveless, so allow the back flow of venous blood.

Question 3

Name the main functions of the heart

Answer 3

Delivery of deoxygenated blood to the lungs for oxygenation

Delivery of oxygenated blood to the body

Delivery of nutrients

Removal of waste

Question 4

Describe the main layers of the heart wall

Answer 4

• Endocardium: squamous cell epithelium
• Myocardium: involuntary striated muscle cells and collagen
• Epicardium
• Pericardium: double membraned sac that fixes the heart in place, lubricates and prevents infection.

Question 5

What are the 2 main ways in which heart valves usually fail?

Answer 5

1. Stenosis: calcification of the valves, causing them to allow less blood through so the ventricles must contract harder to push the blood through → ventricular hypertrophy→ HF.
2. Regurgitation: unidirectional flow of blood is lost. When the ventricles contract, blood is pushed back into the atria as well as the arteries causing congestion. (Left: pulmonary congestion; Right: venous congestion)
   
   • → Dilation of blood vessels and ventricles (loss of muscle tone) → HF.

Question 6

What is the effect of atrial fibrillation on the cardiac cycle?

Answer 6

Passive filling of the ventricles continues, however there is a loss of atrial ‘kick’ which is needed to fill the ventricles against the rising pressure from passive filling. (30% lost)

This causes under-filling of the ventricles and a loss of cardiac output.

Question 7

What is systolic heart failure?

Answer 7

Loss of power of contraction of the ventricles

Question 8

What is diastolic heart failure?

Answer 8

Relaxation of the ventricles in diastole is impaired, therefore the ventricles do not passively fill as effectively → less blood to be pumped out during systole.

Question 9

What is the ejection fraction?

Answer 9

The percentage of blood ejected from the ventricles during ventricular systole from the total blood that was in there at the beginning of systole.

Question 10

How do you calculate cardiac output?

Answer 10

SV x HR = CO

(70ml x 70bpm = 4900ml)

Question 11

Name the 3 most common causes of heart failure

Answer 11

Coronary Artery Disease:

• Post MI
• Chronic ischaemia

Hypertension:

• Struggling against high afterload

Valvular disease:

• Regurgitation of a valve: volume overload (congestion)
• Stenosis of a valve: extra force needed to overcome

Question 12

Name other causes of heart failure

Answer 12

• Cardiomyopathies
• Arrhythmias
• Drugs (anti-arrhythmics, cytotoxics)
• Toxins (alcohol, cocaine, mercury)
• Endocrine (diabetes, thyroid disease, adrenal disease)
• Nutritional (thiamine deficiency, obesity)
• Infiltrative (sarcoidosis, amyloidosis, haematochromatosis)
• Infective (HIV)

Question 13

What is high output cardiac failure?

Name 3 causes

Answer 13

• Pregnancy
• Hyperthyroidism
• Anaemia

More common in younger people.

Caused by higher demand on the heart (e.g. anaemia- lack of oxygen means the heart has to work harder to deliver oxygen to tissues)

Question 14

Name some symptoms of left-sided heart failure

Answer 14

• Dyspnoea
• Fatigue
• Orthopnoea
• Paroxysmal nocturnal dyspnoea
• Nocturnal cough (+/- pink, frothy sputum)

Most symptoms are due to backlog of blood into the lungs (higher preload)

Question 15

Name some symptoms of right-sided heart failure

Answer 15

• Peripheral oedema
• Facial engorgement
• Nausea, anorexia
• Reduced mobility

Symptoms caused by venous congestion in the body

Question 16

What is cor pulmonale?

Answer 16

Right-sided HF secondary to pulmonary disease.

Can present with right-sided signs only

Question 17

Name some signs of left-sided heart failure

Answer 17

• Bilateral basal inspiratory crackles
• Cardiac wheeze (irritation in small airways of wheeze, monophonic)
• Pulmonary oedema
• Pleural effusion
• Right ventricular heave (caused by pulmonary hypertension)

Question 18

Name some signs of right-sided heart failure

Answer 18

• Peripheral oedema
• Tender hepatomegaly (+/- pulsatile)
• Raised JVP
• Displaced apex beat
• Facial engorgement
• Abdominal distention (ascites- fluid backing up into liver; congestion in the portal venous system → liver failure, clotting disorders, may present with easy bruising)

Question 19

Name some signs of reduced cardiac output

Answer 19

• Low systolic BP (cold peripheries, high capillary re-fill time, peripheral/central cyanosis)
• Narrow pulse pressure
• Pulses alterans (heart contracts differently with each beat)

Question 20

Name some bedside investigations for heart failure

Name some possible findings

Answer 20

ECG:

• Left ventricular hypertrophy: Largest R wave + largest S wave = >45mm (in chest leads)
• Left axis deviation: Lead I positive and lead III negative (limb leads)
• Normal axis: Lead I and lead III both positive
• Right axis deviation: Lead I negative and lead III positive
• Strain: ischaemia (ST depression, T wave inversion)

Question 21

Name some blood tests for heart failure

What do the various findings mean?

Answer 21

• BNP (B-type natriuretic peptide/ Brain natriuretic peptide)
  
  • Protein released by the ventricular myocardium when stressed
  • Normal <100 pcg/ml
  • Raised 100-400 pcg/ml
  • High >400 pcg/ml
• U&Es: Cardiac medications can impair renal function
• FBC:?anaemia
• LFTs: HF can cause liver failure

Question 22

What types of imaging can be used to detect HF?

What signs are indicative of heart failure in this type of imaging?

Answer 22

• Chest X-ray
  
  • Alveolar oedema
  • Kerley B lines
  • Cardiomegaly
  • Upper love Diversion (majority gas exchange occurs in the upper part of the lungs away from the fluid, therefore blood is re-directed here)
  • Pleural Effusion

Question 23

Name 2 special imaging tests that can be used to detect HF

What specifically do these tests detect?

Answer 23

• Echocardiogram
  
  • Ejection fraction
  • Wall size and motion
  • Valvular disease
• Cardiac magnetic resonance imaging
  
  • ​Ventricular function
  • Wall size and motion

Question 24

What are the management strategies for acute heart failure?

Answer 24

• A-E assessment
• Oxygen
• IV access and monitoring
• IV furosemide
• Diamorphine
• Nitrates (GTN infusion)
• NIV (CPAP)

Question 25

What are the management strategies for chronic heart failure?

Answer 25

Medical: * ACE-inhibitors * B-blockers * Diuretics * Treat underlying cause (e.g. HTN, arrhythmias) Surgical: * Cardiac resynchronisation (pacemaker) * Treat underlying cause (e.g. valvular disease, IHD)

Question 26

Name some lifestyle management strategies for chronic heart disease

Answer 26

* Smoking cessation * Fluid intake restriction * Alcohol reduction * Salt restriction * Cardiac rehabilitation (exercise) * Regular weighing (monitoring)