Sudden Cardiac Arrest: Common Causes and Risk Factors
Sudden cardiac arrest (SCA) is a life-threatening condition that often occurs in individuals with underlying heart diseases. While it can affect anyone, most cases happen to people with a history of heart problems or specific medical conditions that impact heart function.
1. History of Myocardial Infarction
One of the most common factors associated with sudden cardiac arrest is a prior heart attack, also known as myocardial infarction. Damage to the heart muscle from a heart attack can disrupt the heart's electrical system, increasing the risk of dangerous arrhythmias that may lead to cardiac arrest.
2. Cardiomyopathies and Structural Heart Diseases
Cardiomyopathies — diseases that affect the heart muscle — are also significant contributors to SCA. Conditions such as hypertrophic obstructive cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy can weaken the heart or interfere with its normal electrical activity. These structural abnormalities make the heart more prone to sudden rhythm disturbances.
Types of High-Risk Cardiomyopathies:
- Hypertrophic obstructive cardiomyopathy
- Arrhythmogenic right ventricular cardiomyopathy (ARVC)
3. Ion Channel Disorders
Another group of conditions that can trigger sudden cardiac arrest are ion channelopathies — genetic disorders that affect the heart's electrical activity. Examples include Long QT Syndrome, Short QT Syndrome, and Brugada Syndrome. These disorders can lead to irregular heartbeats and increase the likelihood of sudden cardiac events, especially in young individuals without structural heart disease.
4. Severe Emotional or Psychological Stress
Intense emotional stress can also play a role in sudden cardiac arrest. When the body experiences extreme psychological trauma, the sympathetic nervous system becomes highly activated, while the parasympathetic nervous system is suppressed. This imbalance can directly affect heart rhythm and potentially cause primary cardiac arrest. Additionally, stress may impact the respiratory center in the brain, leading to hyperventilation and respiratory alkalosis, which can further contribute to heart and breathing failure.
Key Takeaways
Understanding the underlying causes of sudden cardiac arrest is crucial for prevention and early intervention. Individuals with a history of heart attack, structural heart disease, or inherited rhythm disorders should be especially vigilant. Managing stress and seeking timely medical care can also significantly reduce the risk of SCA.