Introduction
Acute left ventricular failure is a sudden diminution in the function of the left ventricle.
When this happens, pulmonary capillary and venous pressure increase beyond plasma oncotic pressure.
There is resultant accumulation of oedema fluid in the pulmonary interstitial spaces and alveoli.
Aetiology
- Hypertension
- Myocardial infarction
- Arhythmias
Clinical features
- Dyspnoea
- Orthoponea
- Paroxysmal nocturnal dyspnoea
- Cough
- Heamoptysis
- Restlessness
- Wheezes
- Hypoxia
Differential diagnoses
- Pulmonary thromboembolism
- Bronchial asthma
- Cardiac tamponade
Complications
- Acute renal failure
- Right-sided heart failure
Investigations
- Plain chest radiograph
- Electrocardiography
- Echocardiography
- Pulmonary function tests
- Arterial blood gasses
- Electrolyte, Urea and Creatinine
- Cardiac catheterization
Treatment objectives
- To improve pump performance of the failing ventricle
- To reduce the cardiac workload
- To control salt and water retention
Non-drug treatment
- As in hypertension
Drug treatment
Diuretics
Furosemide
Adult:
- 40 – 80 mg by slow intravenous injection stat, then 40-160 mg orally or intravenously daily in 1or 2 divided doses for maintenance.
Child:
- Neonate:
- 0.5 – 1 mg/kg by slow
intravenous injection every 12 24 hours (every 24 hours if post-menstrual age is under 31 weeks)
- 0.5 – 1 mg/kg by slow
- 1 month – 12 years:
- 0.5-1 mg/kg (maximum 4 mg/kg), repeated every 8 hours as necessary
- 12 – 18 years:
- 20 – 40 mg every 8 hours; higher doses may be necessary in resistant cases
Angiotensin Converting Enzyme Inhibitors
Captopril
Adult:
- 6.25-12.5 mg daily orally, then 25 mg in divided doses daily (maximum 150 mg daily) for maintenance
Child:
- not licensed for use in children
Or:
Lisinopril
Adult:
- 2.5 mg orally daily; 5 – 20 mg daily for maintenance
Child:
- Neonate:
- initially 10 μg/kg orally once daily; monitor blood pressure
carefully for 1 – 2 hours, increased as necessary up to 500 μg/kg daily in 1-3 divided doses
- initially 10 μg/kg orally once daily; monitor blood pressure
- 1 month 12 years:
- initially 100 μg/kg orally once daily, monitor blood pressure carefully for 12 hours, increased as necessary up to a maximum of 1 mg/kg daily in 1-2 divided doses
- 12 – 18 years:
- initially 2.5 mg daily, monitor blood pressure carefully for 1-2 hours; usual maintenance dose 10 – 20 mg daily in 1 – 2 divided doses (maximum 40 mg daily if body weight is >50 kg).
Morphine
May require morphine
Adult:
- 5-10 mg orally, subcutaneously or intramuscularly (usually a single initial dose)
Child:
- Not listed for this indication
Digoxin
Adult:
- 125-250 μg orally daily may be required
Aminophylline
Adult:
- up to 250 mg by slow intravenous injection stat
Supportive measures
- Oxygen
- Nurse in cardiac position
Notable adverse drug reactions, caution and contraindications
- Use ACE inhibitors, aminophylline and digoxin with caution
- Monitor potassium levels closely
- Monitor fluid input and output
Prevention
- Adequate control of hypertension