Sudden cardiac death (SCD) is a sudden and unexpected death caused by a change in heart rhythm or arrhythmia. It is a leading cause of death worldwide, and given its unexpected nature, it often occurs in apparently healthy individuals.

SCD poses a significant challenge to clinicians, as predicting its occurrence and preventing it is difficult. However, researchers have identified certain factors that increase the risk of SCD, and predictive examinations can help identify individuals who are at high risk of SCD.

Defining Sudden Cardiac Death

Sudden cardiac death is defined as an unexpected death due to cardiovascular causes that occurs within one hour of the onset of symptoms or when the person was last seen alive and did not have any significant symptoms of ill-health prior to this time.

It is important to note that SCD does not include deaths that are due to known non-cardiac causes such as trauma or drug overdose.

Causes of Sudden Cardiac Death

Sudden cardiac death is mainly caused by two types of arrhythmias- ventricular fibrillation, and ventricular tachycardia.

Ventricular fibrillation is the most common cause of SCD and occurs when the heart’s electrical system misfires, causing the heart to quiver instead of pumping normally. Ventricular tachycardia, on the other hand, is a rapid and abnormal heart rhythm that originates in the lower chambers of the heart.

Other causes of SCD are congenital heart disease, myocarditis, coronary artery disease, and hypertrophic cardiomyopathy.

Risk Factors for Sudden Cardiac Death

The following factors increase the risk of SCD:.

A personal history of heart disease or heart attack
A family history of sudden cardiac death
Age above 45 years for men, and above 55 years for women
High blood pressure
Diabetes
Smoking
Obesity
A sedentary lifestyle
Use of certain medications or recreational drugs

Predictive Examinations for Sudden Cardiac Death

Due to the unexpected nature of SCD, identifying individuals who are at high risk of SCD is difficult. However, certain predictive examinations can help identify such individuals and aid in early intervention to prevent SCD.

The following are some of the commonly used predictive examinations:.

Electrocardiogram (ECG)

An electrocardiogram is a non-invasive test that records the electrical activity of the heart. This test is done by attaching electrodes to the skin of the chest, arms, and legs.

An ECG can help identify abnormal heart rhythms that increase the risk of SCD.

Echocardiogram

An echocardiogram is a non-invasive test that uses ultrasound waves to create images of the heart. This test can help identify structural abnormalities in the heart that increase the risk of SCD.

Cardiac Magnetic Resonance Imaging (MRI)

A cardiac MRI is a non-invasive test that uses magnetic fields and radio waves to create images of the heart. This test can help identify structural abnormalities in the heart that increase the risk of SCD.

Tilt Table Test

A tilt table test is a non-invasive test that evaluates changes in heart rhythm and blood pressure caused by changes in position. This test can help identify individuals who are at high risk of SCD due to abnormal heart rhythms.

Genetic Testing

Genetic testing can help identify individuals who carry certain gene mutations that increase the risk of SCD. This test is particularly useful for individuals with a family history of SCD or a personal history of sudden unexplained fainting.

Conclusion

Sudden cardiac death is a significant public health challenge. Despite its unexpected nature, various predictive examinations can help identify individuals who are at high risk of SCD and aid in early intervention to prevent SCD.

It is crucial to identify and manage risk factors for SCD to reduce the burden of this condition.