Sudden death

What is sudden death?

Sudden death is a sudden and unexpected cardiac arrest that occurs in people who appear to be in good health.

Prognosis

As it is unexpected, there is no possible way to prevent or control sudden death. If the affected patient does not receive immediate medical attention, they will die as a result of cardiac arrest.

Symptoms of sudden death

Sudden death shows no previous symptoms. However, some signs can help to identify it quickly:

• Near fainting episodes;
• Loss of consciousness;
• Lack of response to stimuli;
• Ceasing to breathe;
• Loss of normal skin tone - turning purplish-blue.

Causes of sudden death

The most common cause of sudden cardiac death is ventricular fibrillation, which is a kind of arrhythmia that causes the heart muscle to be unable to contract as usual. This situation makes regular heartbeats impossible, consequently preventing the pumping of blood throughout the body. The longer the cardiac arrest lasts, the more serious the problem will be due to the body’s organs, including the brain, not receiving blood.

Other reasons why cardiac arrest occurs is the existence of a previous cardiovascular disease. Among the main heart diseases that can cause sudden death are the following:

• Hypertrophic cardiomyopathy: This is a genetic disease characterised by thickening of the heart - in most cases, of the left ventricle. It is the leading cause of sudden death in adults under the age of 50;
• Dilated cardiomyopathy: Dilation occurs in the left ventricle and systolic dysfunction that makes it impossible for the heart to pump blood. Most causes are unknown although a viral aetiology has been implicated in some cases;
• Arrhythmogenic right ventricular dysplasia of the right ventricle: this is an inherited disease in which there is a progressive loss of myocytes that are replaced by adipose tissue. It affects adults who are not over 40 years old;
• Brugada syndrome: This is a heart disease characterised by a series of episodes of polymorphic ventricular tachycardia that can cause fainting or sudden death;
• Long QT syndrome: This is characterised by cardiac arrhythmias due to different structural abnormalities in the sodium and potassium channels of the heart;
• Catecholaminergic polymorphic ventricular tachycardia: This is a hereditary condition in which hearts have abnormal receptors that become excessively sensitive to adrenaline and increased tendency to abnormal heart rhythm (ventricular tachycardia).

Can sudden death be prevented?

Since sudden death occurs in seemingly healthy patients, its prevention is difficult. However, some risk factors are associated with sudden cardiac death.

• Age - Between birth and the first six months of age (sudden infant death) and between 45 and 74 years.
• Gender - sudden death is more frequent in men than in women.
• Cardiovascular risk factors – people with cardiovascular risk factors (obesity, diabetes, smoking ecetera.) are more at risk of sudden death.
• Family history of sudden cardiac death or sudden cardiac arrest - individuals with such family history is associated with 1.5 - 1.8-fold increased risk of sudden death.

Treatments

The only effective treatment to stop sudden death is early defibrillation, which involves an electrical shock to the heart using paddles or patches that try to restart the heart's activity.

If a nearby defibrillator is not available, cardiopulmonary resuscitation (CPR) may be performed, with cardiac massage and mouth-to-mouth breathing applied. Survivors of sudden cardiac death should have an implantable cardioverter-defibrillator for prevention of such deadly events in the future. In addition, family screening is advisable.