Sudden Death Syndrome

Dr. Andrew Krahn, MD, FRCPC, and Kirsten Bartels, MSc, CCGC, Genetic Counsellor, discusses Sudden Death Syndrome and how it is diagnosed and treated.

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Dr. Andrew Krahn, MD, FRCPC, and Kirsten Bartels, MSc, CCGC, Genetic Counsellor, discusses Sudden Death Syndrome and how it is diagnosed and treated.
Video transcript

Featuring Dr. Andrew Krahn, MD, FRCPC, and Kirsten Bartels, MSc, CCGC, Genetic Counsellor

Duration: 3 minutes, 40 seconds

Dr. Andrew Krahn: Sudden death is very common. Thirty thousand Canadians die suddenly every year in Canada. One out of a thousand people every year – that’s a very common problem. Ninety percent of people, when they collapse and die, they can’t be saved or aren’t resuscitated.

There’s two main causes of sudden cardiac arrest. The first is when there’s a problem with the arteries, the plumbing in the heart. That’s coronary artery disease. The second one is when there’s a problem with the heart muscle. A technical term for that is cardiomyopathy.

About 10% of people will have a cause that’s really driven by an inherited reason or a genetic cause. Those two main causes of cardiac arrest, the first one being the arteries in the heart. We have genes that program our arteries, things like cholesterol and blood pressure.

The second one would be the genes that control or program our heart muscle cells. Many of the times, people with those genetic changes are unaware of them. Half of the time when a person collapses or dies suddenly, they’re unaware that they carry those risks factors in their genes.

Kirsten Bartels: Genes are the instructions for the building blocks of our body. They allow our bodies to grow and develop and function properly. There are two main ways in which genes can cause conditions that can predispose to sudden cardiac death.

One main way our genes that are involved in the heart’s electrical system, and these can cause fatal arrhythmias, and they’re part of conditions for example: long QT syndrome or Brugada Syndrome.

The second main way is genes that are involved in the heart muscle cells, and these can cause heart muscle diseases, which can also lead to fatal arrhythmias. And one of the most common examples is hypertrophic cardiomyopathy, where the heart muscle is thicker than expected.

Dr. Andrew Krahn: Several ways they can be recognized: the first would be a person presents and has a symptom, like a fainting spell, and then gets tested, and this comes up as a question for an explanation of their fainting spell.

Second would be that they have a heart test, and that heart test shows a clue that one of these conditions is present. The third would be when something’s happened to their family member, and the question about whether it’s inherited, or they are at risk comes up and then they’re evaluated.

The tests that are done for these conditions are really usually quite simple. The first would be tests of the heart’s wires or electrical system. The one we all know well is an EKG, just a heart tracing, or a heart monitor.

Sometimes we’ll do an exercise test and look at the signal of the heart in that circumstance. Another test would be pictures of the heart, looking at the heart muscle. The one that’s used most often is called an echocardiogram, and that’s an ultrasound of the heart. And the last test would be a genetic test. This is to look at the code that programs the wires in the heart. And that’s something as simple as a spit test or a blood test.

Treatments are typically very simple. Something like a once-a-day pill to prevent getting into trouble, things like treating a fever, avoiding certain medications that may make the condition worse, or lifestyle recommendations about exercise and activity.

Sometimes treatments for patients who have a more severe case of the disease involve more invasive things, like things called an implantable defibrillator or ICD. These are for patients where they have active, life threatening conditions that continue to recur.

If you’re looking for more information about inherited causes of sudden death, you should go see your doctor, who may connect you with a local heart specialist.

Presenter: Dr. Andrew Krahn, Cardiologist, Vancouver, BC

Local Practitioners: Cardiologist

Genetic Heart Conditions ( 68 participated.)

Sudden Death Syndrome


Thirty thousand (or one out of a thousand people) in Canada every year die from Sudden Death Syndrome..


A genetic condition that effects the heart muscle is called Cardiomyopathy.


Another way genes can effect our heart is by effecting the arteries or the 'plumbing' of the heart. Effects on cholesterol and blood pressure can lead to cardiac arrest.


Most patients that carry the genes which predispose them to Sudden Death Syndrome are aware of their condition.


There are several tests that can be administered to diagnose genetic conditions, including having an EKG, a stress test, an echocardiogram and genetic testing.


Treatment for genetic conditions are typically fairly simple and involve things like avoiding fever and certain medications.


Patients who have more severe symptoms may need to have a defibrillator or 'ICD' implanted.

This content is for informational purposes only, and is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your physician or other qualified healthcare professional with any questions you may have regarding a medical condition.

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