Doctors Suggest Sudden Cardiac Death Runs in Family

Medical and genetic tests should be conducted on relatives of people who experience sudden cardiac death, to obviate future occurrences and prevent families from passing anything on to future generations, the Israel Heart Society recommends.

Israeli cardiologists repairing a congenital defect at Wolfson Medical Center last year.
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If we follow this procedure, relatives of those who have tested positive for a genetic disease that could lead to sudden death can help remove the threat of the disease spreading within their family, says Dr. Michael Arad, chairman of myocardial and pericardial diseases for the Israel Heart Society and a senior cardiologist at Sheba Medical Center in Tel Hashomer.

Some 35 cases of sudden cardiac death (SCD) in people under the age of 30 - and one or two in athletes - are reported in Israel annually. Most of these cases involve people who have no known cardiac or blood vessel disease or any other risk factors.

The Heart Society set out to address the occurrence of SDC and establish methods to examine such cases genetically, improve diagnosis and prevent incidences of sudden death within the same family.

The medical group has issued a position paper recommending a series of genetic tests for relatives of sudden death victims, which would become standard medical practice. The society called on the Health Ministry to approve the new tests as part of the state-subsidized medical services.

Tests to trace genetic mutations for hereditary heart diseases are currently conducted in Israel for research purposes only.

The rate of sudden death incidents in the country is one in 100,000 for those under the age of 30, and one in 1,000 over the age of 40. In half of the cases, sudden death below the age of 40 is attributed to hereditary heart diseases and could be the first expression of the disease in the family.

These are primarily genetic diseases caused by an isolated mutation that can be found in a blood test - and in these cases, 50 percent of the first-degree relatives of the carrier are also expected to carry the mutation. They run a higher risk of falling victim to sudden death themselves at some stage, unless they start treatments to prevent heart disease.

According to the paper, "Sudden death is generally caused by a sudden cardiac arrhythmia, which is more frequent during physical activity or excitement." The main reasons for sudden death in young people include primary myocardial disease, genetic disorder in the arteries leading to and from the heart, a family heart disease (such as high blood cholesterol ), and genetic syndromes related to heart rate and connective tissue function.

A committee headed by Dr. Arad recommends performing autopsies in cases of sudden death, as is customary today. If the autopsy does not exclude death from a hereditary disease, the society recommends testing the deceased's family members for genetic syndromes.

This test is also recommended for cases in which the family refuses an autopsy, for religious reasons, for example.

Research shows that about 20 percent of SCD cases are caused by cardiac arrhythmia, although the heart appears in order in the autopsy. In half of these cases, testing family members will locate the genetic syndrome.

"Sometimes a life-endangering cardiac arrhythmia or sudden death constitute the first expression of cardiac disease in the family and a correct diagnosis will enable early intervention to prevent additional SCD cases in the family," Arad says.

Among the procedures recommended in the paper are medical documentation of family diseases going three generations back, electrocardiography (ECG or EKG ), eco-Doppler test, effort test, Holter heart rate test and blood fat level tests. Additional tests will be held in clinics should any abnormalities be detected.

The paper recommends that those under the age of 40 who are at risk for sudden death conduct a diagnostic catheterization and magnetic resonance imaging (MRI ) to determine if there are any blocked blood vessels.

A diagnosis of genetic mutation will be accompanied by counseling services.

"Before a genetic examination is conducted, the patient's relatives will receive genetic counseling on the likelihood of a disease running in the family, the chances of arriving at certain genetic diagnosis, and how this awareness would help the patient or his family," Arad says.

"The family as a whole and each relative individually may decide whether to undergo genetic diagnosis," he continues. "Sometimes families don't cooperate with disastrous results. After the mutation in the family is diagnosed, further counseling will explain its significance for the mutation carriers' treatment, to prevent the disease from being passed on to the next generation."