Sudden Cardiac Death
Sudden cardiac death (SCD), also known as sudden cardiac arrest, occurs when
the heart suddenly and unexpectedly stops beating. Blood stops flowing to the
brain and the organs, and death results if the patient doesn't get treatment
within minutes. Sudden cardiac death is responsible for half of all heart disease
Sudden cardiac death is not the same thing as a heart attack. During a heart
attack, blood flow to the heart is blocked or slowed down. But SCD can sometimes
happen during recovery from a heart attack.
During SCD, the heart stops beating because of an arrhythmia, or ventricular
fibrillation (v-fib), a problem with the heart's electrical system. During v-fib,
the ventricles quiver rapidly and irregularly, instead of beating normally.
Patients who are treated within minutes, with a device that sends an electrical
shock to the heart (called a defibrillator), can often be saved. Afterwards,
they're likely to have an implantable cardioverter defibrillator surgically
placed under their skin. This will monitor the heart at all times for dangerous
rhythms, and it delivers a shock to the heart if a dangerous rhythm is detected.
SCD occurs most often in adults in their mid 30s to mid 40s. It affects twice
as many men as women. Because it generally happens to people who were not known
to have any problem with their heart it's important to know the risk factors
Risk factors for sudden cardiac death
The primary risk for SCD is having coronary artery disease. But most of the
people who experience SCD don't know they have coronary artery disease.
Other risk factors for SCD include the risk factors for heart disease:
High blood pressure
And additional risk factors for SCD include Problems with the heart rhythm:Abnormal heart rate
Unusually rapid heart rate that can occur even at rest
Low ejection fraction (the measurement of the amount of blood that pumps with
A recent study of SCD in women has shown that, although most women who experience
SCD had no history of heart attack, 94 percent of them had at least one risk
factor for heart disease.
Researchers looked at data from the Nurses Health Study. They followed 121,701
women for 22 years, ending in 1998. During that time period, there were 244
cases of SCD. Some of the findings:
Women who smoked 25 or more cigarettes per day had a four-fold increased
risk of SCD
Women with diabetes had a three-fold increased risk of SCD
High blood pressure caused a 2.5 fold increased risk
Obesity brought with it a 1.6 fold increased risk
Women who had parents who died of SCD before age 60 were also at increased
Additionally, the study showed that the main cause of SCD in women appears
to be "chaotic heart rhythm." This is the same cause of most SCD
cases among men.
Fish oil supplements may reduce risk of SCD
New research indicates that increasing adults' intake of omega-3 fatty acids
could greatly reduce the incidence of sudden death from heart arrhythmias.
Omega-3 fatty acids are found in oily fish, such as salmon, but you can also
get them from supplements. Previous research has linked these fatty acids
to a lower risk of fatal heart rhythm disturbance. The most recent research
estimated the effect of raising the levels of adults' omega-3s through the
use of supplements.
Researchers used computer models and past medical findings to simulate an
adult community of 100,000 Americans. Findings indicated that increasing the
levels of omega-3s could save 58 lives each year.
This is especially interesting in light of the fact that about 50 percent
of adults who die of sudden cardiac arrest have had no warning signs. These
people are unlikely to have had a defibrillator implanted in their chest.
Defibrillators are able to help the heart rhythm get back to normal.
Ask your doctor if you're a good candidate for fish oil supplements. Or you
can make a point of getting omega-3 fatty acids from your diet by including
plenty of wild salmon, lake trout, herring, sardines, walnuts, brazil nuts,
hazelnuts, fortified egg yolks.
American Journal of Preventive Medicine, October 2006; Circulation, Rapid Access Issue, 15 April 2003; National Heart, Lung, and Blood Association