cardiac failure

Question 1

What is cardiac failure?

Answer 1

Inability of the cardiac output to meet the body’s demands despite normal venous pressures 

Question 2

What are the different ways you can classify heart failure?

Answer 2

1. Left or right sided
2. Low- output or high- output:
   - Low-output HF is much more common than high-output HF.
   - Low-output HF occurs when cardiac output is reduced due to a primary problem with the heart and the heart is unable to meet the body’s needs.
   - Conversely, high-output HF refers to a heart that has a normal cardiac output, but there is an increase in peripheral metabolic demands that the heart is unable to meet.
3. Can be Systolic or Diastolic:
   - Systolic failure: inability of the ventricle to contract normally, resulting in decreased CO. Ejection fraction <40%.
   - Diastolic failure: inability of the ventricle to relax and fill normally, causing increased filling pressures
4. can be Acute or Chronic:
   - Acute: new onset acute or decompensation of chronic heart failure characterised by pulmonary and/or peripheral oedema with/without signs of peripheral hypoperfusion
   - Chronic: develops slowly. Venous congestion is common but arterial pressure is maintained well until late

Question 3

What are some causes of systolic heart failure?

Answer 3

• Ischaemic heart disease
• Long- standing hypertension
• dilated cardiomyopathy
• Myocardial infarction

Question 4

What are some causes of diastolic heart failure?

Answer 4

• Long-standing hypertension (significant left ventricular hypertrophy reduces filling of the left ventricle)
• Aortic stenosis
• Hypertrophic cardiomyopathy
• cardiac tamponade
• constrictive pericarditis
• Restrictive cardiomyopathy

Question 5

What are some causes of left sided heart failure?

Answer 5

(left ventricular failure):
● Ischaemic heart disease
● Hypertension
● Cardiomyopathy
● Aortic valve disease
● Mitral regurgitation

Question 6

What are some causes of right heart failure?

Answer 6

(right ventricular failure)
● Secondary to left heart failure (in which case it is called congestive cardiac failure)
● Infarction
● Cardiomyopathy
● Pulmonary hypertension/embolus/valve disease
● Chronic lung disease
● Tricuspid regurgitation
● Constrictive pericarditis/pericardial tamponade

Question 7

What are some causes of biventricular heart failure?

Answer 7

“affecting both ventricles of the heart”
● Arrhythmia
● Cardiomyopathy (dilated or restrictive)
● Myocarditis
● Drug toxicity

Question 8

What are some causes of acute heart failure?

Answer 8

Advanced kidney disease.
Alcoholism.
Blood clot in the lung (pulmonary embolism).
Diabetes.
High blood pressure (hypertension).
Overactive thyroid (hyperthyroidism).
Sleep apnea.
Stroke

Question 9

What are some causes of chronic heart failure?

Answer 9

• Causes: coronary artery disease
• Hypertension
• Valvular disease
• Myocarditis
• Infiltrative diseases
• Infection
• Familial cardiomyopathy

Question 10

What is meant by low output cardiac failure?

Answer 10

(reduced cardiac output and fails to increase with exertion):
- left heart failure
- right heart failure
- biventricular failure

Question 11

What is meant by high output cardiac failure?

Answer 11

(increased demand) - less common 

Cardiac output is normal, but there is an increase in peripheral metabolic demands which exceed those that can be met with maximal cardiac output

Question 12

What are some causes of high output cardiac failure?

Answer 12

• Anaemia
• Arteriovenous malformation  
• Beri beri 
• Pregnancy 
• Paget’s disease 
• Hyperthyroidism 
• Thyrotoxicosis

Question 13

What presenting symptoms of left heart failure can be found in the history ?

Answer 13

LHF, or left ventricular failure (LVF), causes pulmonary congestion (pressure builds up on the LHS of the heart and there is backpressure to the lungs) and there is systemic hypoperfusion.

1. Dyspnoea
2. Orthopnoea 
3. Paroxysmal nocturnal dyspnoea 
4. Fatigue 
5. Nocturnal cough (± pink frothy sputum)

Question 14

What presenting symptoms of right heart failure can be found in the history?

Answer 14

Right heart failure causes venous congestion (pressure builds up behind the right heart) and pulmonary hypoperfusion (reduced right heart output).

• Swollen ankles 
• Fatigue 
• Increased weight (due to oedema) 
• Reduced exercise tolerance 
• Abdominal swelling and discomfort
• Anorexia 
• Nausea 

Question 15

What signs of left heart failure can be found on physical examination?

Answer 15

• Tachycardia 
• Tachypnoea 
• Displaced apex beat 
• cyanosis
• prolonged cap refill
• hypotension
• Bilateral basal fine crackles 
• Less common signs: pulsus alternans (alternating strong and weak pulse), S3 gallop rhythm (produced by large amounts of blood striking compliant left ventricle), features of functional mitral regurgitation.

Question 16

What signs of right heart failure can be found on physical examination?

Answer 16

“HO ARTT”

Hepatomegaly 
(Ankle/sacral pitting) oedema 
Ascites 
Raised JVP
Tricuspid regurgitation/ Transudative pleural effusions (typically bilaterally)

Question 17

What investigations are used to diagnose heart failure?

Answer 17

1. BNP (1st Line) → if raised suggests diagnosis of cardiac failure. Sensitive but not specific.
2. Transthoracic Echocardiogram → diagnostic. Done if BNP is raised for confirmation:
   - Can calculate Ejection Fraction ⇒ EF<40% = HFrEF (systolic dysfunction). EF>50% = HFpEF (diastolic dysfunction).
   - Systolic vs Diastolic Dysfunction
3. CXR → alveolar oedema, Kerley B lines, cardiomegaly, upper lobe diversion, pleural effusion (ABCDE):
   - Alveolar shadowing (patchy consolidation) 
   - Kerley B lines 
   - Cardiomegaly 
   - Upper Lobe Diversion 
   - Pleural Effusion 
   - Assess heart size (PA film)
4. ECG and ABG
5. Bloods → rule out anaemia, hyperthyroidism (lead to high-output heart failure):
   - May cause hypervolaemic hyponatraemia (tx with fluid restriction)

Question 18

What is meant by cardiogenic shock? how is it managed?

Answer 18

“severe cardiac failure with low blood pressure”
management:
- IV inotropes(e.g. dobutamine) 
- Managed in ITU 
- TREAT THE CAUSE! (e.g. MI, arrhythmia) 
- Rate or rhythm control for dysrhythmias 
- Ventilation: CPAP (for type 1 respiratory failure) or mechanical ventilation if above fails 

Question 19

How is cardiac failure managed?

Answer 19

1. Conservative management
   - Weight loss if BMI >30.
   - Smoking cessation
   - Salt and fluid restriction - improves mortality
   - Supervised exercise-based group rehabilitation programme for people with heart failure.
   - Offer annual influenza and one-off pneumococcal vaccinations for patients diagnosed with heart failure.
2. Medical:
   - For fluid overload prescribe loop diuretics (e.g. furosemide or bumetanide). These do not confer mortality benefit.
   - Mortality benefit: BASH (BB, ACEi, spironolactone, hydralazine)
   a. 1st line = ACE-I and beta-blocker
   - Consider ARB if intolerant to ACE-I.
   - Consider hydralazine if intolerant to ACE-I/ARB.
   b. If symptoms persist and NYHA Class 3 or 4 consider:
   - Aldosterone antagonists = spironolactone or eplerenone.
   - Hydralazine and a nitrate for Afro-Caribbean patients.
   - Ivabradine if in sinus rhythm and impaired EF.
   - Digoxin = useful in those with AF. This worsens mortality but improves morbidity.