Left Ventricular Failure

Question 1

How common is it?

Answer 1

• Asymptomatic ventricular dysfunction = ~4%
• 1-2% adults have HF in developed world, prevalence rising to 10% in over 70s.
• Increasing prevalence due to increased survival rate after coronary events and secondary prevention.

Question 2

Who does It affect?

Answer 2

• Asymptomatic ventricular dysfunction = ~4%
• 1-2% adults have HF in developed world, prevalence rising to 10% in over 70s.
• Increasing prevalence due to increased survival rate after coronary events and secondary prevention.

Question 3

What causes it?

Answer 3

• CHD and hypertension are most common causes.
• Valve disease – Aortic stenosis can cause LVH due to chronic excessive afterload. Aortic/mitral regurgitation, ASD/VSD and tricuspid incompetence cause excessive preload.
• Heart failure secondary to myocardial disease – MI, heart block, AF. Hypertension (increased vascular resistance, often with LVH but preserved ejection fraction). Cardiomyopathies, drugs, toxins, endocrine causes (hyper/hypothyroidism, Cushing’s syndrome, adrenal insufficiency, excessive GH, pheaeochromocytoma), nutritional, infiltrative (connective tissue disorders), infective.
• High output failure – when cardiac output is normal or increased in the face of much increased needs. Causes include: anaemia, pregnancy, hyperthyroidism, Paget’s disease of bone, arteriovenous malformations, beriberi.

Question 4

What risk factors are there?

Answer 4

• Hypertension, coronary heart disease, previous MI, diabetes, sleep apnoea, congenital heart defects, viruses, alcohol use, arrythmias.

Question 5

How does it present?

Answer 5

• Symptoms - Cough (frothy or blood tinged mucus), decreased urine production, orthopnoea, fatigue, weakness, faintness, irregular or rapid pulse, palpitations, shortness of breath, paroxysmal nocturnal dyspnoea, weight gain from fluid retention, wheeze (cardiac ‘asthma’), nocturia, cold peripheries.
• Signs – Patient may look ill and exhausted, with tachypnoea, cool peripheries, peripheral and/or central cyanosis. Tachycardia at rest, low systolic blood pressure, displaced apex (LV dilatation), crackles in lung bases (pulmonary oedma).

Question 6

Which conditions may present similarly?

Answer 6

• ARDS, COPD, cirrhosis, emphysema, Goodpasture syndrome, myocardial infarction, nephrotic syndrome, pneumonia, pneumothorax, pulmonary oedma, PE, pulmonary fibrosis, respiratory failure, venous insufficiency.

Question 7

How would you investigate the patient?

Answer 7

• FBC, U&E, BNP.
• CXR – Features = ABCDE. Alveolar oedma (bat’s wings), Kerley B lines (intersistial oedema), Cardiomegaly, Dilated prominent upper lobe vessels, pleural Effusion.
• ECG may indicate cause.
• Echocardiogram is key – may indicate cause and can confirm presence or absence of LV dysfunction.
• Endomyocardial biopsy rarely needed.

Question 8

What treatment/s would you consider? What risks and benefits of treatment are there?

Answer 8

• Lifestyle – smoking cessation, less salt, optimize weight and nutrition.
• Treat cause.
• Treat exacerbating factors.
• Avoid exacerbating factors.
• Drugs: the following are used:
  1. Diuretics – Reduce risk of death and worsening heart failure. Loop diuretics to relieve symptoms.
  2. ACE-i – improves symptoms and prolongs life. If cough a problem, ARB may be substituted.
  3. Beta-blockers – decrease mortality.
  4. Spironolactone – decrease mortality by 30% when added to conventional therapy.
  5. Digoxin – helps symptoms even in those with sinus rhythm.
  6. Vasodilators – combination of hydralazine and isosorbide dinitrate should be used if intolerant of ACE-i and ARBs.