Sudden Death and Conditions

What do we mean by sudden death?

Sudden death is an unexpected death in an otherwise healthy person, occurring within a short time frame (24 hours) from the onset of symptoms. Some cases of sudden death may have been preceded by chronic illnesses that directly cause death (such as blood clots, strokes, heart attacks, or cancer). In these instances, the death is not classified as sudden death requiring family screening, as it is usually a result of the chronic illness itself.

What is the difference between sudden death, cardiac arrest, and heart attack?

• Cardiac Arrest: A sudden stop of the heart muscle, leading to reduced blood flow to body organs. It can be caused by various heart or other conditions, and if not promptly resuscitated, cardiac arrest leads to sudden death.
• Heart Attack: A severe blockage in the coronary arteries, leading to reduced blood flow to the heart muscle and causing intense chest pain. Heart attacks are among the most common causes of cardiac arrest (though not all cardiac arrests are due to heart attacks).
• Sudden Cardiac Death: An unexpected death occurring within a short time frame (24 hours) from the onset of symptoms.

What is the relationship between sudden death and the need for family screening?

If a sudden death occurs in a family, screening of other family members is necessary to rule out genetic heart conditions that may put other members at risk of sudden death, God forbid.

Who needs family screening when sudden death occurs?

Family screening is required for the first-degree relatives of the person who suffered sudden death if there is suspicion of a genetic disorder by the treating physician (such as death at a young age). These individuals include the deceased's parents, siblings, and children, if any.

What does family screening involve?

Initial family screening includes an echocardiogram, electrocardiogram (ECG), exercise stress test, and lipid profile test. Based on preliminary findings, additional testing such as cardiac MRI or genetic testing may be required.

Is it possible to undergo screening and receive normal results?

The likelihood of discovering genetic diseases in the families of sudden death victims ranges between 20-50%. When normal screening results are obtained, this could be due to several reasons:

• The deceased may have had a non-genetic heart disease that was not diagnosed (not hereditary and doesn’t affect family members), with common causes including blocked arteries or heart failure.
• The presence of a genetic mutation that occurred for the first time in the deceased (not inherited from the family).
• Non-cardiac factors that put the deceased at risk of cardiac arrest that are not inherited, such as pulmonary embolisms (due to immobility, post-surgery, or after childbirth), infections or illness at the time of the event, choking incidents, or brain hemorrhage.

When screening of sudden death patients’ relatives yields normal results, it is generally an indicator that there is no hereditary heart disease. Studies have shown that individuals who are screened and receive normal results live normal lives without an increased risk of sudden death from hereditary heart diseases.

Examples of sudden death include:

• Death while sleeping.
• Death during physical exertion or sports (especially drowning while swimming).
• Death during routine activities, such as talking, praying, or doing household chores.
• Death at a young age without medical explanation.

Does sudden death have preceding symptoms?

Sudden death may be preceded by symptoms such as chest pain, shortness of breath, palpitations, or fainting. These symptoms often correlate with an undiagnosed heart condition. However, sudden death often occurs without prior symptoms, underscoring the importance of family screening even if no symptoms are present.

Causes of Sudden Death

• Inherited Arrhythmias:
  • Brugada Syndrome: A defect in cardiac cell channels causing electrical disturbances that lead to cardiac arrest.
  • Long QT Syndrome: Prolonged electrical activity in the heart's waves, increasing the risk of sudden death, and can be triggered by specific events such as certain medications, exercise, pregnancy, or auditory triggers.
  • Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT): Irregular heart rhythms often causing fainting, directly linked to a sharp increase in adrenaline during physical exertion (though this disease is relatively rare and not all exertional palpitations require screening).
• Structural Heart Disease:
  • Acquired: Conditions such as arterial blockages, weakened heart muscle, valve stenosis or regurgitation, and congenital defects (like heart holes) are classified as structural issues but are not necessarily genetic. They can primarily cause sudden death but do not require family screening.
  • Genetic: Structural heart diseases that cause sudden death and necessitate family screening include hypertrophic cardiomyopathy, right ventricular cardiomyopathy (ARVC), and genetic cardiomyopathies.
• Other Conditions:
  • Aortic Dilatation: Sudden death may occur if the aorta dissects (tears), causing internal bleeding. This condition may be genetic (especially with associated syndromes like Marfan Syndrome) or acquired, with contributing factors such as smoking and high blood pressure.
  • Pulmonary Embolism: Pulmonary embolism is a common non-cardiac cause of cardiac arrest and sudden death, usually acquired (e.g., pregnancy, autoimmune diseases, surgeries, or immobility).
  • Brain Hemorrhage: Severe brain hemorrhage may expose the patient to the risk of sudden death without urgent surgical intervention. Causes include blood thinners, brain tumors, strokes, or high blood pressure.