What is CARDIOGENIC SHOCK?
Cardiogenic shock presents when there is a severe and sudden reduction in the contractility and output of the heart. It is usually caused by a massive heart attack. The condition leads to inadequate tissue perfusion.
Why does this happen and how may it affect the patients health?
This usually happens when a massive heart attack causes damage to more than 50% of the heart muscle of the left ventricle (lower heart chamber).
This is seen more often in
- The elderly
- Anterior infarction (heart attack involving the front side of the heart)
- Prior high blood pressure
In rare instances, cardiogenic shock may be the result of damage to the heart muscle due to trauma (external injury).
Overdose of medications e.g. Beta-blockers (drugs that slow heart rate down) or calcium antagonists may precipitate this condition.
Other heart conditions that may lead to this, include
- Ventricular septal defects (birth defects of heart)
- Valve lesions
- Inflammation of the heart muscle (myocarditis)
What symptoms may the patient experience?
- Patient has a poor (weak) rapid pulse
- Patient is also sweaty and severely distressed
- The patients blood pressure is severely depressed (low blood pressure)
- Cool extremities
- Urinary output is reduced
- There is usually fluid on the lungs (pulmonary oedema), which causes rapid shallow breathing
How is the diagnosis made and what special investigations are required?
Because of the life-threatening nature of cardiogenic shock, several invasive and non-invasive investigations may be required as indicated, which may include
- ECG (may show large Q-waves, indicating a major heart attack, or increased heart enzymes)
- Chest x-ray
- Transesophageal echocardiogram
- Heart catheterisation (angiogram)
- Drug identification (if patient was using any drugs)
What is the treatment and prognosis?
Correct any irregular heart rate and rhythm.
The outcome largely depends on the
- Degree of functional left ventricle (lower heart chamber) available
- Treatment, which is aimed at maintaining circulation until some recovery of heart muscle takes place
These patients need to be treated in a cardiac intensive care unit.
The overall prognosis is poor.
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