Acute Left Ventricular Failure

• Cardiac output


  Is the product of stroke volume x heart rate
• Cardiac output

  The volume of blood ejected by the heart per minute
• Pulmonary oedema

  Where the lung tissue and alveoli are filled with interstitial fluid, interfering with normal gas exchange in the lungs, causing shortness of breath and reduced oxygen saturation
• Presentation of Acute LVF

  Typically presents with acute shortness of breath, exacerbated by lying flat and improves on sitting
• Potential triggers of acute left ventricular failure

  • Iatrogenic (e.g., aggressive IV fluids in a frail elderly patient with impaired left ventricular function)
  • Myocardial infarction
  • Arrhythmias
  • Sepsis
  • Hypertensive emergency (acute, severe increase in blood pressure)
• Acute left ventricular failure occurs when an acute event results in the left ventricle being unable to move blood efficiently through the left side of the heart and into the systemic circulation
• Stroke volume

  The volume of blood ejected during each beat
• Areas where blood backlog occurs in acute left ventricular failure

  • Left atrium
  • Pulmonary veins
  • Lungs
• Acute left ventricular failure is often the result of decompensated chronic heart failure
• TOM TIP: 'Acute left ventricular failure and pulmonary oedema are common in the acute hospital setting. When a nurse asks you to review a breathless and desaturating patient, ask yourself how much fluid that patient has been given and whether they will be able to cope with that amount. For example, an 85 year old patient with chronic kidney disease and aortic stenosis is prescribed 2 litres of fluid over 4 hours and then starts to drop her oxygen saturation. This is a common scenario, and a dose of IV furosemide can work like magic to clear the excess fluid and resolve the symptoms'
• 1. type Natriuretic Peptide (BNP)

  A hormone released from the heart ventricles when the cardiac muscle (myocardium) is stretched beyond the normal range
• Management of acute left ventricular failure

  Patients require hospital admission
• Echocardiography

  Helpful in assessing the function of the left ventricle and any structural abnormalities in the heart
• BNP is sensitive but not specific. When the result is negative, it helps rule out heart failure, but it can be positive due to other causes
• Acute LVF causes a type 1 respiratory failure (low oxygen without an increased carbon dioxide)
• Other causes of a raised BNP

  • Tachycardia
  • Sepsis
  • Pulmonary embolism
  • Renal impairment
  • COPD
• BNP


  • Relaxes smooth muscle in blood vessels
  • Reduces systemic vascular resistance
  • Acts on the kidneys as a diuretic to promote water excretion in the urine
• Ejection fraction

  The percentage of blood in the left ventricle that is squeezed out with each ventricular contraction. An ejection fraction above 50% is considered normal
• When upright

  Gravity takes fluid to the lung bases, leaving the middle and upper areas clear for better gas exchange
• Be cautious with patients who have COPD

  Target saturations may be 88-92%
• Sitting the patient up

  Helps oxygenate the lungs
• Reducing circulating volume in a fluid-overloaded patient

  Allows the heart to pump blood more effectively
• Severe cases may require (guided by an experienced specialist)

  Intravenous opiates, Intravenous nitrates, Inotropes, Vasopressors, Non-invasive ventilation, Invasive ventilation
• Management of patients with acute left ventricular failure

  1. Require hospital admission

  2. Severe cases may require admission to high dependency unit or intensive care unit

  3. Get experienced seniors involved early
• Vasopressors

  • Medications that cause vasoconstriction, increasing systemic vascular resistance and mean arterial pressure
• Diuretics increase the urine output of the kidneys


  Reducing the volume of fluid in the circulation
• Fluid balance monitoring

  Involves monitoring fluid intake (oral and IV), urine output, U&Es, and body weight
• When lying flat

  Fluid in the lungs spreads to a larger area
• The “sodium” mnemonic can be used for remembering the basic management of acute LVF: 'S - Sit up<|>O - Oxygen<|>D - Diuretics<|>I - Intravenous fluids should be stopped<|>U - Underlying causes need to be identified and treated<|>M - Monitor fluid balance'
• Oxygen should be given for reduced oxygen saturation


  Below 95%
• Additional x-ray findings of lung tissue

  • Bilateral pleural effusions
  • Fluid in interlobar fissures (between the lung lobes)
  • Fluid in the septal lines (Kerley lines)
• Inotropes

  • Medications that alter the contractility of the heart
  • Positive inotropes increase the contractility of the heart, cardiac output, and mean arterial pressure
• Vasopressors are commonly used by anaesthetists as a bolus dose or in ICU as an infusion to improve the patient’s blood pressure and tissue perfusion