If someone in your family has suffered a heart attack, sudden cardiac arrest, or sudden cardiac death, it’s only natural to wonder whether you might also be at risk. According to simple statistics, a family history of heart disease makes it more likely that you will also develop heart disease, which in turn, increases your risk for cardiac arrest. To keep your risk of sudden cardiac death as low as possible, it’s important to get clinical testing if you have a family history of heart problems and take measures now to protect your health.
Is Cardiac Arrest Hereditary? Known Causes
While sudden cardiac arrest can and does happen to people with no apparent risk factors, almost all adults who suffer from SCA had known risk factors before the event occurred, many of which tend to run in families.
Most Common Risk Factors
- Coronary artery disease, in which the coronary arteries are narrowed or thickened with plaque, restricting blood flow to the heart (80% of SCAs)
- Previous heart attack (a blockage in part of the heart), especially in the last six months (75% of SCAs)
- Heart failure, in which the heart pumps less effectively (people with heart failure are 6 to 9 times more likely to develop life-threatening arrhythmias)
- Previous stroke (researchers are still trying to understand the link between stroke and SCA)
- Dilated cardiomyopathy (10% of SCAs)
- Hypertrophic cardiomyopathy or arrhythmogenic cardiomyopathy (frequently linked to SCAs in children and athletes)
Lifestyle-Related Risk Factors
- High blood pressure
- High cholesterol
- Alcohol use disorder
- Taking recreational drugs
- Taking antiarrhythmic drugs
Other Risk Factors
- Congenital heart defects or blood vessel abnormalities
- Heart valve problems
- Previous sudden cardiac arrest
- Family history of sudden cardiac arrest or sudden cardiac death
- Abnormal heart rhythms (you or your family members), including long QT syndrome, ventricular tachycardia, catecholaminergic polymorphic ventricular tachycardia, and Wolff-Parkinson-White syndrome
- History of fainting episodes without a known cause, known as syncope
- A significant drop in potassium and magnesium blood levels
Your Risk Based on Family Risk Factors
Now, let’s look at the extent to which each of these risk factors is hereditary and what you can do to reduce your personal risk:
Most Common Causes
Coronary Artery Disease, Heart Attack, Heart Failure, and Stroke
The top heart diseases that are associated with sudden cardiac arrest are often caused by a combination of genetic, lifestyle, and environmental factors. Common risk factors for coronary artery disease, heart attack, and heart failure include:
- Current smoking
- Being overweight
- Being physical inactive
- Eating an unhealthy diet
- Drinking too much alcohol (especially for heart failure and stroke)
- Having high blood pressure
- Having high blood cholesterol (especially for coronary artery disease)
- Having a family history of heart disease
Unsurprisingly, the risk factors for developing heart disease are also risk factors for sudden cardiac arrest.
Many times, a family history of heart disease in itself is a combination of genes, epigenetics, the local environment (passive smoking, air pollution), and lifestyle habits. If the parents are overweight, are sedentary, eat an unhealthy diet, drink too much alcohol, or smoke, it’s more likely that the children will as well, which in turn, increases their risk for heart disease and cardiac events such as heart attack and cardiac arrest.
According to a study published in the New England Journal of Medicine, people with a family history of heart disease are almost twice as likely to suffer from a cardiac event. However, by leading a healthy lifestyle (no current smoking, no obesity, regular physical activity, healthy diet), their individual risk of suffering from a cardiac event was lowered by 46%. This should be extremely encouraging; you can effectively halve your risk of cardiac events—including SCA—by leading a healthy lifestyle!
Other Lifestyle-Related Causes
Recreational and Prescription Drug Use
Numerous studies have linked certain classes of substances with atrial fibrillation, which in turn, increases your risk for heart failure, stroke, and other abnormal heart rhythms. The longer an individual continues to use these substances, the higher their risk.
These substances are:
- Methamphetamines (AKA meth, blue, ice) and amphetamines
Important: If you have been prescribed one or more of these substances by your doctor and you have a family history of heart disease and cardiac events, it’s important to discuss the risks and benefits of the treatment as well as any alternative treatments available. Reducing or stopping a prescription treatment comes with its own risks and should only be attempted under medical supervision.
Antiarrhythmic Drug Use
Antiarrhythmic drugs, including amiodarone, sotalol, flecainide and quinidine, as well as antidepressants, antipsychotics, antibiotics, and methadone, may cause arrhythmias in around 5% of patients. Your risk of arrhythmias from these medications may be higher if you have congenital long QT syndrome or certain genetic variants. Genetic testing can help a medical professional determine the most appropriate medications and ideal dose.
Other Biological Causes
Significant Drop in Blood Levels of Magnesium and Potassium
Electrolytes, including magnesium, potassium, calcium, phosphate, sodium, and creatinine, play an important role in regulating blood pressure, which, in turn, contributes to heart health and your risk of sudden cardiac arrest.
Interestingly, there does appear to be a genetic aspect to blood electrolytes and renal function, which means certain people may be at greater risk of electrolyte imbalances and associated heart problems. If you have family members with blood pressure problems or renal failure, looking into a possible electrolyte connection and making sure you consume foods that are rich in these minerals could help you to reduce your risk.
- Dilated cardiomyopathy. This is a disease that causes an enlargement of the heart chambers and affects their ability to contract, leading to heart failure. Risk factors include genetic diseases as well as alcohol abuse, cocaine use, exposure to heavy metals and some chemotherapy drugs, HIV, Lyme disease, autoimmune disease, diabetes, thyroid disease, high blood pressure, heart attack, coronary artery disease, nutritional and electrolyte problems, and certain muscular dystrophies.
- Hypertrophic cardiomyopathy. This disease causes a thickening of the left ventricle and is the most common cause of SCA in athletes and children. Hypertrophic cardiomyopathy is usually inherited but may not be diagnosed until middle age.
- Arrhythmogenic cardiomyopathy. This is an inherited disorder in which heart muscle becomes replaced with scar tissue and fat. It is a common cause of SCA in athletes and children. Arrhythmogenic right ventricular cardiomyopathy, in particular, has been identified as a latent structural cause of SCA.
- COVID-19-related cardiomyopathy. Heart complications, including cardiomyopathy, heart failure, type 2 heart attack, and stroke, have been associated with COVID-19 infection (1, 2). While COVID-19 is not a risk factor you inherit from your family, your personal risk of COVID-19-related heart problems may be heightened if you have diabetes, obesity, high blood pressure, high cholesterol, ischemic heart disease, or a family history of heart disease.
Important: If you experience any worrying heart symptoms, including chest pain, dizziness, nausea and vomiting, excessive fatigue, fainting, and palpitations, it could be worth getting clinical testing to find out whether you have a COVID-related or congenital heart disease that is only recently getting worse. If any of these symptoms come on suddenly or you have two or more symptoms together, call 911 or ask someone to take you to the hospital as it may be an emergency.
Congenital Heart Defects
Abnormalities in your heart structure, such as a hole in the heart or problems with your heart’s electrical system, are usually present from birth and may be hereditary. If you know you have a heart defect, talk with your doctor or cardiologist to see whether you can safely participate in high-intensity aerobic activities. If family members have a heart defect but you don’t, it’s best to discuss your personal level of risk with a doctor or heart specialist.
Unexplained fainting spells, caused by a range of factors, can be a risk factor for SCA. Syncope can run in families and can also be caused by dehydration, over-eating, exhaustion, heavy sweating, sudden changes in position, or an underlying heart condition. If you or a family member experiences fainting spells, it’s a good idea to go for clinical testing to rule out an underlying heart condition.
Unexplained Cardiac Arrest
Some cases of cardiac arrest, particularly in children, don’t have any obvious underlying cause. These are referred to as “unexplained cardiac arrests.”
Latent Pathogenic Genes
Genetic testing of unexplained cardiac arrest survivors shows that in around 17% of unexplained cardiac arrests, there was a pathogenic gene present, including channelopathy (60%) and cardiomyopathies (40%).
Latent Long QT Syndrome Gene
According to an article in the J Am Coll Cardiol, epinephrine tests can reveal a latent Long QT syndrome mutation known as LQT1 that may put an individual at increased risk for cardiac arrest. If there is a family history of congenital heart disease, genetic testing can help doctors identify genes related to heart issues and recommend that the individual avoid highly strenuous physical activity, if appropriate.
What You Can Do If You Have Risk Factors in Your Family History
There are several things you can do to reduce your risk if family members have suffered sudden cardiac death or have any of the risk factors for SCA:
- Get a clinical assessment to find out if you have heart problems and follow your doctor’s prescribed treatment regimen.
- Have your blood pressure and cholesterol levels checked every year.
- Have your electrolyte levels checked if you or a family member has blood pressure or kidney problems.
- Stop drinking, smoking, and taking recreational drugs.
- Participate in regular physical exercise.
- Maintain a healthy diet.
- If overweight, return to a healthy weight.
In case the worst happens and you suffer a sudden cardiac arrest, it’s a good idea to have a user-friendly automated external defibrillator on hand so that someone close by can perform high-quality CPR to keep oxygen-rich blood circulating around your body and deliver a shock to stop a fatal heart rhythm like ventricular fibrillation or ventricular tachycardia.
The Philips HeartStart FRx, HeartSine Samaritan PAD 350P (semi-automatic), HeartSine Samaritan PAD 360P (fully automatic), HeartSine Samaritan PAD 450P (semi-automatic with real-time CPR feedback), and Defibtech Lifeline are all excellent defibrillators for home use.
Cardiac Arrest Has Hereditary Components, But You Can Reduce Your Individual Risk
Is cardiac arrest hereditary? Many of the risk factors are. But if you lead a healthy lifestyle and get tested for heart conditions early on, you can lower your individual risk significantly.
In many cases, a sudden cardiac arrest in the family is a wake-up call to the victim and their relatives that necessitates significant lifestyle changes, clinical testing, preventative medical treatments, and purchasing emergency equipment such as an AED. If a relative has suffered a cardiac event, taking action now might just save your life.