Acute Heart Failure

Question 1

What is Acute Left Ventricular Failure?

Answer 1

Sudden Onset/Worsening of Heart Failure.

Question 2

What is Pulmonary Oedema?

Answer 2

Lung tissues and alveoli become full of interstitial fluid.

Question 3

How does Acute Left Ventricular Failure cause Pulmonary Oedema (3)?

Answer 3

1. The left ventricle is unable to adequately move blood out into the body.
2. It causes a backlog, increasing the amount of blood stuck in the left atrium, pulmonary veins and lungs.
3. Increased volume and pressure.

Question 4

Triggers of Acute Left Ventricular Failure (4).

Answer 4

1. Iatrogenic e.g. Aggressive IV fluids in frail elderly patient with impaired left ventricular function.
2. Sepsis.
3. MI.
4. Arrhythmias.

Question 5

Causes of De-Novo Acute Heart Failure (4).

Answer 5

1. Ischaemia.
2. Viral Myopathy.
3. Toxins.
4. Valve Dysfunction.

Question 6

Causes of Decompensated Acute Heart Failure (4).

Answer 6

1. ACS.
2. Hypertensive Crisis.
3. Acute Arrhythmia.
4. Valvular Disease.

Question 7

Clinical Presentation of Acute Left Ventricular Failure (3).

Answer 7

1. Rapid Onset SOB exacerbated by lying flat and improves on sitting up.
2. Type I Respiratory Failure.
3. Cough with Frothy White/Pink Sputum & Wheeze.

Question 8

Examination Findings of Acute Left Ventricular Failure (4).

Answer 8

1. Observations : Tachypnoea, Tachycardia, Reduced Oxygen Saturations.
2. 3rd Heart Sound and Wet Bibasal crackles.
3. Hypotension - Cardiogenic Shock.
4. Raised JVP and Peripheral Oedema - if RHF too.

Question 9

Investigations of Acute Left Ventricular Failure (4).

Answer 9

1. Treat before confirming diagnosis.
2. BNP Blood Test.
3. Echocardiography.
4. CXR.

Question 10

What is BNP and when is it released?

Answer 10

B-Type Natriuretic Peptide - a hormone released from the ventricles when the myocardium stretches beyond its normal range (indicating overload).

Question 11

What is the function of BNP? (2)

Answer 11

1. Relax smooth muscle in blood vessels to reduce systemic vascular resistance.
2. Diuretic Action on Kidney - Promote Water Excretion to reduce circulating volume.

Question 12

Give 6 Differential Diagnoses of BNP Raise.

Answer 12

Raised : >100mg/Litre
1. Heart Failure.
2. Tachycardia.
3. Sepsis.
4. Pulmonary Embolism.
5. Renal Impairment.
6. COPD.

Question 13

Why are Echocardiograms useful?

Answer 13

Assessing function of the left ventricle (ejection fraction) and structural abnormalities.

Question 14

What is the ejection fraction?

Answer 14

Percentage of blood in LV squeezed out with each ventricular contraction. Normal > 50%.

Question 15

Management of Acute Left Ventricular Failure (6).

Answer 15

POUR SOD :
1. POUR - Pour Away/Stop IV Fluids.
2. S - Sit Up (to clear upper lungs).
3. O - Oxygen If saturation is below 95%.
4. D - Diuretics e.g. IV Furosemide/Bumetanide 40mg STAT.
5. Continue regular medications - stop B-blockers if HR < 50, 2nd/3rd Degree AV Block or Shock.
6. Maybe Vasodilators - Nitrates (if concomitant MI, Hypertension, Valvular Disease).

Question 16

Management of Severe/Cardiogenic Shock in Acute Left Ventricular Failure (4).

Answer 16

1. Intravenous Opiates e.g. Morphine (Vasodilator).
2. NIV - CPAP (to open airways and alveoli) or later Intubation & Ventilation.
3. Inotropes e.g. Noradrenaline, Dobutamine to strengthen the force of heart contractions and improve heart function in failure.
4. Intra-aortic balloon pump if in shock.