Sudden Cardiac Arrest is a Family Matter

We have previously highlighted the factors that put you at risk of coronary artery disease (see post here). Among these factors, we identified family history as one of the leading contributors to sudden cardiac arrest.

A new Danish study released in November 2012, has provided additional details, and demonstrates a direct link between family history and SCA.

Research indicates that relatives of young sudden cardiac death victims appear to have a much greater risk of cardiovascular disease than the general population.

During 11-years of follow-up and tracking sudden cardiac death victims, there were 292 incidents of cardiovascular disease among those with relatives who suffered sudden cardiac death, compared to 219 incidents in the background population, representing a 33 percent increase.

Researchers found the risks were particularly high when the relative who suffered cardiac arrest was younger than 35. The findings suggest a large hereditary component of sudden cardiac death.

Sudden Cardiac Arrest

“Since the cardiovascular conditions on which we focused are treatable, early identification of at-risk persons is potentially a life-saving action,” wrote Mattis Flyvholm Ranthe, MD, of the Statens Serum Institute in Copenhagen. “Our findings are the first of their kind and support the initiation of cascade screening in families experiencing a sudden cardiac death, with customization of screening based on the underlying condition suspected to have caused the death and family member ages.”

Many of the risks linked to sudden cardiac arrest include:

  • Smoking
  • Hypertension
  • Obesity
  • Diabetes
  • Sedentary lifestyle
  • Alcohol (more than one to two drinks per day)
  • Age (after 45 for men and 55 for women)
  • Being male (2-3 times the risk)

However, previous studies have shown numerous links to sudden cardiac arrest through genetic mutations, including primary arrhythmia syndromes (electrical malfunctions), cardiomyopathies (heart muscle deterioration), familial hypercholesterolemia (elevated cholesterol levels), and ischemic heart disease (poor blood supply to the heart).

Further Details

To explore the link between family history and sudden cardiac arrest, researchers performed a prospective, population-based cohort study using Danish national registries. They identified 470 individuals ages 1 to 35 years who suffered a sudden cardiac death from 2000 to 2006, and 3,073 relatives.

  • Compared with the general population, the relatives had a greater risk of developing cardiovascular disease during follow-up
  • First-degree relatives — parents, children, siblings — had a greater risk of cardiovascular disease compared with second-degree relatives, such as half-siblings, grandparents, grandchildren etc…
  • Risks were particularly high for first-degree relatives younger than 35
  • The risks among the relatives were greater when the initial sudden cardiac death was verified by autopsy.

Sudden Cardiac Arrest Risks

Recent studies have shed light on many risk factors related to Sudden Cardiac Arrest (SCA); often a quick and silent killer.

Up to ninety percent of those who die from SCA have evidence of plaque (fat and cholesterol) in two or more major arteries. Plaque buildup leads to one common underlying cause: coronary artery disease.

Sudden Cardiac Arrest Risks

The Mayo Clinic (a medical research group) reports that because the link between coronary artery disease and SCA is so strong, the same factors that put you at risk of coronary artery disease also may put you at risk of SCA.

These include:

• Family history of coronary artery disease
• Smoking
• Hypertension
• High blood cholesterol
• Obesity
• Diabetes
• Sedentary lifestyle
• Alcohol (more than one to two drinks per day)
• Age (after 45 for men and 55 for women)
• Being male (2-3 times the risk)

Sudden Cardiac Arrest Risks

The American Heart Association reports that Sudden Cardiac Arrest Risks can be caused by almost any known heart condition, they list the following specific factors that further increase the odds:

Scarring or enlargement of the heart from a previous heart attack or other causes can make someone more prone to developing life-threatening ventricular arrhythmias.

Cardiomyopathy is a deterioration of the heart muscle; typically a root cause of SCA in athletes.

Heart medications, under certain conditions, can set the stage for arrhythmias that cause SCA. Antiarrhythmic drugs sometimes can produce lethal ventricular arrhythmias, even at normal doses.

Electrical abnormalities, such as Wolff-Parkinson-White syndrome (a condition with an extra electrical pathway in the heart) and long QT syndrome (a disorder of the heart’s electrical activity) may cause SCA in children and young people.

Blood vessel abnormalities, particularly in the coronary arteries and aorta, may be present in young SCD victims. Adrenaline released during intense physical or athletic activity often acts as a trigger for SCA when these abnormalities are present.

Recreational drug use, even in people without organic heart disease, is a cause of SCA.

There are numerous risk factors related to SCA, but there are also ways to reduce the risk. Next week we will highlight some SCA prevention methods that you can incorporate into your everyday life. Don’t forget to check back!