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)
• Females
• 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
• Echocardiogram
• 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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