A professor of Medicine and Consultant Cardiologist at the University of Ilorin Teaching Hospital, Ilorin, Kwara State, Philip Kolo, discusses the risk factors of sudden death in this interview with LARA ADEJORO

What is sudden death?

When we talk about sudden death, there are many definitions that have been proposed but I will start with the one that is commonly used, which is the one by the World Health Organisation. What it means is that sudden death is a death of an individual who apparently is in good health from natural causes within 24 hours of the onset of acute symptoms, the time and mode of death of such persons are unexpected. It is unexpected because the person appears to be enjoying good health, without any major or overt illness and it's from natural causes; meaning that it is not from accidents or natural disasters. The second definition is that the pathologists feel that 24 hours is too long, so the same death of an individual who is apparently enjoying good health but dies from natural causes within one hour of the onset of acute symptoms.

What are the acute symptoms and the indicators one would be noticing that such an incident may occur?

There are many indicators that such may occur like chest pain, dizziness, fainting, body weakness, and difficulty in breathing. It can also be the feeling of weakness on one side of the body; the majority of causes are related to the heart but we have some that are not related to the heart but can be due to intracranial or central nervous system disorders like intracranial bleeding or cerebral infraction – what a layman will refer to as a stroke, it can lead to sudden unexpected death.

Heart problem is often blamed for sudden death, why is that so?

The heart is a major organ of the body that supplies blood through the blood vessels to various parts of the body for oxygen and nutrients. If the heart is not functioning well, that organism will not survive well; when the heart of a human stops working or beating, that person is dead. The brain is another major organ in the body, so if something is happening inside the brain like the bleeding I mentioned before or you have a seizure or convulsion that is persistent, it can lead to sudden unexpected death but the bulk of people who died suddenly actually have heart-related problems. You can also have sudden death from other body systems. A patient could start having massive gastrointestinal bleeding, or from the respiratory system which can be fatal.

When and how does sudden death occur in adolescents and young adults?

In young people, sudden unexpected deaths are not too common compared with middle-aged and elderly. Some statistics put it as one in 50,000, or one in 80,000 young people, especially among those that are predisposed, like those involved in competitive sports. Some young people may experience sudden unexpected death, especially if they have background cardiac problems that they are not aware of. That is why it is recommended that young individuals who are going to be involved in competitive sports like football or young individuals going for military or parametric recruitments should have good cardiovascular screening because some of them may be nursing background heart problems without knowing and in the process of the competition, it places a lot of stress on the heart and such young individuals may experience sudden death. It's not common among the young but they can experience it if they have heart muscle diseases such as hypertrophic cardiomyopathy, where the heart muscle is unduly hypertrophied especially the septum. When you look at the heart, the chambers are divided into the right and left ventricles by the septum, so the upper part of this septum may get unduly thickened due to heredity. The affected individuals inherit the gene that makes that part of the heart to be thickened and narrows the outlets of the left ventricle such that the heart may not be able to eject its content easily, especially when they are involved in competitive sport or exercise. It tends to cause severe obstruction to the outflow of the left ventricle and if that happens, such individuals can die suddenly during exercise.

Another major cause is arrhythmogenic right ventricular dysplasia. The cells in the right ventricle (myocytes) are prematurely destroyed by apoptosis which affects the function of the right ventricle and it becomes dilated. The major challenge in this condition is that they often have disorders of heart rhythm (cardiac arrhythmias) which makes the beating or contraction to be irregular and such patients can develop high-grade arrhythmia (severe) and they can die suddenly. Another condition that can cause sudden death in the young is myocarditis –which is the inflammation of the cardiac muscle. This can come from viral infections like adenoviruses, coxsackie B viruses, and HIV infection which affect the myocardium. Some of these patients could have gone to camps where a large number might have gathered and could have symptoms of viral infection and may have myocarditis or symptoms of heart failure. Young people can have hereditary disorders, such as hereditary long QT syndromes which predispose them to a particular cardiac arrhythmia called Torsades de Pointes, and be a cause of sudden death.

Another major reason young people can have sudden cardiac death is congenital heart disease which is a structural defect in the heart at birth; for example, abnormal communication between chambers through holes in the heart. Another cause of death among the young is rheumatic heart disease – a long time consequence of infection with Group A streptococci. So, the body responds to this infection by producing antibodies that cross-react with body tissues and the immune system does not only destroy these bacteria but also damages special tissues in the body present in the skin, joints, central nervous system, and heart.

Another cause is systemic hypertension – if left untreated will progress to hypertrophy of the heart and it is the reason for acute myocardial infection, heart failure, and kidney failure. Another cause is coronary artery disease characterised by the narrowing of the arteries that carry blood to the heart by the formation of plaques. Sometimes there could be an injury to the surface of narrowed parts and with inflammation setting in there, there is the formation of a thrombus or clot in the narrow parts which may lead to complete obstruction of these arteries which can lead to the death of the heart muscle or heart attack. Some of them also abuse alcohol, and drugs and these can cause rhythm disorders and lead to sudden death. For athletes, many of these conditions mentioned are often the cause of sudden death among them.

Apart from all you've mentioned, what are the other risk factors?

Cigarette smoking is another major reason for both stroke and coronary artery disease. Other people at risk are those with a family history of sudden death. In the middle age population to the elderly, we have many cardiovascular risk factors increasing the risks of sudden deaths. Many of the cardiovascular diseases don't cause symptoms at the initial stages and when they start showing symptoms, most patients are already developing or about to develop complications.

How can parents or guardians know if a young person is at risk of sudden death?

It's usually difficult to know but the first thing is to know the family history. If you have cases of sudden death in the family, then such need to be investigated. We expect that those who die suddenly without any identified symptom should have a postmortem examination such that the cause of that death can be properly established because there are so many reasons some people can die suddenly and most of the time, they are related to cardiovascular events from a heart attack, stroke and so on. Sometimes, when adults come to the hospital, we detect cardiac abnormalities, such as hypertrophic cardiomyopathy, that tend to run in families. So, if the father or the mother has been diagnosed with that, then the children should be screened. Then those who are into competitive sports need to be screened also. Apart from cardiovascular examination, they need to have electrocardiography. Adults need to have a cholesterol check. If you have a family history of sudden death, you have to start screening early, twice yearly.

Should people with a family history of sudden death avoid or limit physical activity?

No, they should not. However, we need to determine an individual's risk and appropriate advice is given. We need to do screening for hypertension, diabetes, and other cardiac disorders and treat them appropriately. We need to have defibrillators in public places because cardiac arrest can happen anywhere and one of the major interventions can be the defibrillator. We need to be teaching people how to do cardiopulmonary resuscitation and that will be life-saving. Sudden death can be prevented if you know your risks after screening and appropriate measures are adopted. Lifestyle modification is very important for dietary adjustment, weight reduction, and regular exercise. Sometimes when you say people should not eat red meat, they avoid red meat and start going for the intestines or organ meat, so those people do have an elevation of another fraction of lipids called triglycerides. So, they should avoid red meat, especially cow meat but they can take poultry meat after they have removed the skin and take a lot of fruit and vegetables They also need to reduce salt intake, avoid cigarette smoking, and drugs that make people feel high e.g cocaine, marijuana, etc.

Is there a link between extreme anger, cardiac arrest, and sudden death?

Anger comes from emotional feelings, probably one has seen something that one doesn't like, and that can bring a cascade of events and reactions, and such an individual can have increased blood pressure that can increase the risk of a cardiovascular event. So, there could be a link actually so we learn how to control our anger. This is also true of many other events that will exact our cardiovascular system and lead to sudden death. We have had cases of men who engage in public sexual activities and because of the anxiety and fear that is associated with it, some of them could have elevated blood pressure, and we have cases of those who have died suddenly through the process of the acts, so all those things are related to uncontrolled hypertension, uncontrolled blood sugar, and dyslipidemia.