In our previous post, we discussed what sudden cardiac arrest (SCA) is and how it significantly differs from a typical heart attack. Now it’s time to address the leading causes of this potentially fatal occurrence.

As SCA can often be fatal, it’s vital to know what causes it.

What Can Cause Sudden Cardiac Arrest?

If you’ve read our previous post, you know that SCA can happen suddenly and without warning. SCA stops the heart from beating, which is why it is vital to perform CPR or chest compressions and have someone to call 911.

But what causes such a sudden and deadly stoppage of the heart?

The primary and most common cause of SCA is an abnormal heart rhythm. That means that the heart’s electrical activity has suddenly become chaotic, which results in its inability to pump blood. Without blood flowing through the body, a person can die in a matter of minutes.

To be more precise, the abnormal heart rhythm is called ventricular fibrillation or VF. It causes the electrical signals in the lower chambers of the heart (ventricles) to become chaotic. The result of this is that the ventricles go into fibrillation, which is essentially a chaotically irregular and fast trembling that cannot adequately pump blood.

The Possible Conditions That Lead to SCA

Many conditions and diseases can lead to SCA; the most common are:

  • Heart attack – SCA is often connected to a heart attack, which weakens the heart and increases the risk for SCA.
  • Coronary artery disease – plaque on the inner walls of the arteries causes arterial rigidity and narrowing. This restricts the blood flow to the heart, which can result in a heart attack or SCA. Coronary artery disease is the most common cause of SCA for people 35 and older.
  • Long QT syndrome – a disorder that affects the heart’s electrical system and leads to an abnormal rhythm, which can potentially lead to SCA.
  • Brugada syndrome – similar to Long QT syndrome, and it can also cause SCA.
  • Congenital heart defects – any heart defect can increase the risk of SCA, even after surgery to address the defect.
  • Cardiomyopathy – causes the heart muscle to become thick or enlarged and weaker. People with this condition have a more fragile heart, resulting in a higher chance of suffering from SCA.

Several other conditions can lead to SCA, but these traits increase your risk as well:

  • Family history of heart disease
  • High blood pressure or cholesterol
  • Diabetes
  • Obesity
  • Smoking
  • A sedentary lifestyle
  • Age: older than 45 for men or 55 for women

If you want to know more about the causes of sudden cardiac arrest, feel free to contact us.