SUDDEN cardiac death is defined as unexpected mortality from diseases of the heart that occurs shortly after symptoms are experienced (usually within 60 minutes).

This can occur in patients without heart disease and is often devastating due to its sudden and unexpected nature, especially in the young, fit and seemingly healthy individual. However, sudden cardiac death is commonly seen in people with narrowing of the blood vessels that supply the heart by atherosclerotic (fatty) plaques, a condition termed coronary artery disease.

Approximately eight million people worldwide die from sudden cardiac death annually.

DON’T IGNORE WARNING SIGNS

Certain factors are warning signs that may be ignored by the individual or ascribed to less important conditions. These include the heart beating fast (palpitations), chest pain, shortness of breath, fainting, excessive tiredness, and dizziness at rest or with exertion.

While healthy individuals with no prior warning signs can suffer from sudden cardiac death, risk factors include chronic illnesses such as diabetes mellitus also called “sugar”, high blood pressure, smoking, family history of early coronary artery disease, obesity, high cholesterol, excessive alcohol intake, and lack of physical activity. These factors are related to the narrowing of the blood vessels supplying the heart, resulting in heart attacks and heart disease from reduced blood flow (ischemic heart disease).

Other risk factors are patients with enlarged heart, diseases of the valves, abnormal structures, previous heart attacks and abnormal rhythms.

PHYSICAL ACTIVITY AND SUDDEN

CARDIAC ARREST

Physical activity that causes increase in heart rate and blood pressure such as running, climbing, swimming, and cycling may uncover and precipitate conditions that result in sudden cardiac death.

DIAGNOSING CONDITION

Diagnosing and predicting sudden cardiac death can be difficult. Abnormally elevated heart enzymes, thyroid hormones and electrolytes, use of certain prescription drugs and substances such as cocaine, may be predictive. Studies that may predict the risk of sudden cardiac death include chest X-ray, electrocardiogram (ECG), electrophysiologic testing (testing the electrical activity of the heart), echocardiogram, and coronary angiogram outlining the blood vessels of the heart.

Sudden cardiac death events may present with cardiac arrest where the individual is unresponsive, not breathing and has no pulse. Cardiopulmonary resuscitation (CPR) is then indicated and can even be performed by lay persons with minimal training. An automated external defibrillator increases the chance of survival. After resuscitation care using drugs, reversing causes, and sometimes surgery, implanting pacemakers and ablating abnormal pathways in the heart are also important as repeat arrest may occur soon after the initial event.

PREVENTION

Preventing sudden cardiac death can sometimes be difficult and may still occur after consulting the physician and getting a clean bill of health. However, regular routine check-ups, eating a balanced diet, avoiding smoking, illicit drugs and excessive alcohol while controlling weight, blood pressure, cholesterol, and blood sugar are some measures that can reduce the risk.

Dr Romayne Edwards is a consultant emergency physician at the University Hospital of the West Indies and an associate lecturer at the University of the West Indies.