Medically Fit For Exams
Medically Fit For Exams

Heart Failure

Definition

  • The heart can no longer work adequately to maintain sufficient tissue perfusion for normal metabolism
  • Can be split into left and right heart failure – but in reality they occur together (congestive heart failure)
  • Can be split into systolic and diastolic heart failure

 

Risk factors

  • Strong
    • Hypertension
    • Coronary artery disease (atherosclerosis)
    • Previous MI
    • Congenital heart defects
    • COPD
    • Diabetes
    • Age
    • Male
    • Renal insufficiency
    • Cardiac hypertrophy
    • Family history
  • Weak
    • Obesity
    • Tachycardia
    • High salt/coffee diet
    • Smoking
    • Alcohol intake
    • Low SES

 

Differential diagnosis

  • COPD
  • Pneumonia
  • PE
  • Cirrhosis
  • DVT
  • Pericardial disease/infection
  • Venous stasis

 

Epidemiology

  • 1 – 2% prevalence in western world
  • 5-10 per 1000 incidence per year in UK
  • 5% of emergency admissions
  • Men more than women
  • Deaths is increasing
    • More people are getting CHF
    • Less people are dying of MI, so go on to get heart failure

 

 

Aetiology

  • Cardiovascular causes
    • Hypertension
    • Previous MI
    • Coronary artery disease/coronary heart disease
    • Congenital heart disease
    • Cardiomyopathy (dilative)
    • Valvular heart disease
    • Myocarditis
    • Pericardial disease
  • Endocrine imbalance
    • Diabetes
    • Thyroid disease
    • Acromegaly
    • Phaeochromcytoma
  • Pulmonary
    • COPD (cor pulmonale)
  • Toxin induced
    • Heroin
    • Cocaine
    • Alcohol
    • Amfetamine
  • Infiltrate disease
    • Amyloidosis
    • Sarcoidosis
    • Haemochromatosis
  • Systemic vascular disease
    • Lupus
    • Rheumatoid arthritis
    • Systematic sclerosis
  • Electrolyte imbalance
    • Hypocalcaemia
    • Hyponatremia
    • Hypokalemia
    • Hypophosphatemia
  • Infection
  • Drug induced
    • Sulfonamides

 

Clinical features

  • Right and left sided heart failure almost always occur together – but in terms of cause, can split into right and left heart failure
  • Left heart failure
    • Signs of pulmonary congestion
    • Dry cough
    • Crackles
    • SOB
    • Tachypnoea
    • Hypertension
    • Paroxysmal nocturnal dyspnoea
    • Orthopnoea
    • Pleural effusion
  • Right heart failure
    • Dependent oedema (legs, sacrum)
    • Raised JVP
    • Abdominal distention (ascites)
    • Hepatomegaly
    • Splenomegaly
    • Anorexia/nausea
    • Nocturnal diuresis
    • Swelling of hands
    • Hypertension
  • General
    • Cardiomegaly
    • Fatigue
    • Chest pain (may go with pleural effusion/pulmonary oedema)
    • Murmur (eg mitral regurgitation - systolic)

 

Pathophysiology

  • Remodelling can occur as a result of serious injury
    • MI, cardiomyopathies, hypertension, valvular heart defects
    • Prevents normal contraction of the heart muscle
  • Mitral regurgitation
    • May result from remodelling
    • Inability of mitral valve to close fully, allowing blood to lead back in during systole
    • Back-leak increases the volume load on the left ventricle and contributes further to remodelling (hypertrophy, dilatation)
  • ANP released in response to atrial stretch
  • BNP released in response to ventricular stretch

 

Investigations

  • Apex beat displacement
  • Echocardiogram (may also do intra-oesophageal)
    • May see dilatation (systolic heart failure)
    • Hypertrophy (diastolic heart failure)
    • Can measure ejection fraction (low in systolic heart failure)
  • ECG
    • Can measure hypertrophy by height of QRS complexes
    • V2 + the higher of V4&V5 > 37mm
  • CXR
    • May show cardiomegaly
    • Pulmonary oedema
    • Pleural effusion
  • BNP elevation
  • Cardiopulmonary exercise tolerance test

 

Management

  • Low sodium diet
  • Fluid restriction (especially in hospital) and daily weight monitoring
  • Exercise
  • ACE inhibitors – reduces BP, so reduces afterload and the amount of work the heart needs to dp
  • Beta blockers – reduces contractility and heart rate, reducing the amount of work needed
    • Not to be given in acute failure
  • Aldosterone antagonists (potassium-sparing diuretics) – reduce BP, so reduced afterload
    • Can cause hyperkalemia
    • Eg spironolactone
  • Diuretics
    • Lower BP
    • Fast acting – can reduce pulmonary oedema in hours
  • Digoxin
    • Positive ionotrope
    • Inhibits Na/K pump (which increases Na and Ca exchange, so intracellular calcium is increased - to increase contractility
    • Doesn’t improve survival

 

Prognosis

  • Poor prognosis
  • Depends on stage
    • Lower stages have about 10% 1-year risk of mortality
    • Higher stages have 40-60% 1-year risk of mortality
Heart failure.docx
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