Is it a genetic condition?


You inherit a lot of things from your parents, including your eye color and height. But not all genetic traits are good.

An arrhythmia is an example of a genetic health problem. These can also be called hereditary or familial conditions.

Although sudden cardiac death is extremely rare, affecting only 3 in 100,000 one person 2011 study found that about 70 percent of people under the age of 40 who died of sudden heart problems had underlying cardiac arrhythmias that they had inherited. This means that the problem with the heart’s ability to beat regularly has been passed on by one or both parents.

Sometimes the problem is limited to a malfunction of the electrical signals in the heart, the American Heart Association said. But in about a third of cases, arrhythmias may develop due to structural problems, or the way the heart is formed.

Your heart works using a complex electrical system that pulses through a detailed and delicate structure. Anytime any of these electrical signals are turned off, or any part of the structure is damaged or malformed, it can create a host of problems.

Experts Divide hereditary cardiac arrhythmias into two categories:

  • Primary electrical diseases. These are arrhythmias that develop from problems with electrical signals and not from structural problems in the heart.
  • Secondary arrhythmia syndromes. Arrhythmias like these will develop along with structural heart disease.

All hereditary cardiac arrhythmias are considered relatively rare conditions, but the most common types are:

Read on to learn more about the main types of hereditary heart arrhythmias.

Familial atrial fibrillation

Atrial fibrillation, also known as AFib or AF, is the most common type of cardiac arrhythmia overall. This condition involves the upper chambers of the heart, called the right and left atria.

In AFib, the right and left atria shake and are not coordinated in pumping. This leads to compromised blood flow to the lower chambers of the heart or the right and left ventricles.

AFib can cause blood to collect in the atria. This increases the risk of developing blood clots, which are potentially fatal. A 2016 study estimated that up to a third of all strokes that occur in people aged 65 and over are due to AFib.

This condition can develop with age, but recent studies found that up to 30 percent of people with AFib inherited it. According to MedlinePlus Genetics, several genes have been linked to the development of familial AFib:

  • KCNQ1
  • KCNH2
  • ABCC9
  • LMNA
  • PRKAG2
  • RYR2
  • SCN5A

Many of these genes provide instructions as your heart trains on how its electrical channels are to be “wired”. If these channels are not wired correctly, ions, tiny electrically charged particles, will have trouble transmitting signals through the muscles in your heart.

Brugada syndrome

Brugada syndrome is another type of electrical problem in the heart that causes the ventricles to beat irregularly or too quickly. When this happens, your heart cannot effectively pump blood to the body.

This can cause serious difficulty as many of your organs depend on constant, strong blood flow to function properly. In severe cases, Brugada syndrome can cause ventricular fibrillation, a life-threatening irregular heartbeat.

A 2016 study have shown that at least 23 genes are associated with this syndrome. The the primaries are:

Catecholaminergic polymorphic ventricular tachycardia

This is a rare form of hereditary arrhythmia. People with catecholaminergic polymorphic ventricular tachycardia (PCVT) will experience a very rapid heartbeat during physical activity, called ventricular tachycardia.

In CPVT, ventricular tachycardia usually occurs during some form of exercise. Sometimes you may notice it before the ventricular tachycardia occurs. You can do this by observing symptoms known as premature ventricular contractions (PCVs) during exercise.

With this type of genetic arrhythmia, the structure of the heart is usually not affected. It usually appears in people 40 years of age and younger.

Specific genes related to this condition are:

MedlinePlus Genetics says that RYR2 mutations account for about half of TVPC cases, while CASQ2 only causes about 5 percent. These two genes are responsible for making proteins that help maintain a regular heartbeat.

Long QT syndrome

In this condition, the muscles that cause the heart to contract or beat take too long to recharge between push-ups. This can disrupt the rhythm and regularity of your heartbeat, leading to other problems. Although long QT syndrome can be caused by drugs or other heart conditions, many can be inherited.

A 2016 study discovered that 15 genes are associated with this disease, but the most common are:

Most genes linked to familial arrhythmias are autosomal dominant, but some autosomal recessive disorders can also cause long QT syndrome. Genoa KCNQ1 and KCNE1 are linked to rarer types of long QT syndrome called Jervell and Lange-Nielsen syndromes. In addition to hereditary arrhythmias, people with these conditions also suffer from deafness.

Short QT syndrome

This is a rare type of inherited arrhythmia. According to MedlinePlus Genetics, only about 70 cases of short QT syndrome have been diagnosed since it was recognized in 2000. Many other cases may exist, but they have not been diagnosed because this syndrome can occur without any symptoms.

With this condition, the heart muscle does not take enough time to charge between beats. It may not cause any symptoms in some people. But in others, it is the cause of sudden cardiac arrest or death.

Genoa related to this condition include:

Timothy’s Syndrome

With this rare disease, the heart has structural and electrical problems. Electrical problems come in the form of a long QT interval, or the time it takes for the heart to charge after each beat.

A long QT interval can lead to ventricular tachycardia, an often fatal arrhythmia. Ventricular tachycardia is the cause of death in approximately 80 percent of people with this syndrome.

Since this syndrome can also affect other parts of the body like the nervous system and the immune system, many people with Timothy’s syndrome die in childhood. It is an autosomal dominant syndrome, which means that only one copy of an altered gene can lead to it. But because few people with Timothy syndrome survive to adulthood, it is usually not passed from parent to child.

Instead, Timothy’s syndrome usually develops due to new mutations in the CACNA1C gene. This gene helps manage the flow of calcium ions through the heart muscles, affecting the regularity of your heartbeat.

Wolff-Parkinson-White syndrome

Another problem with the heart’s electrical system, Wolff-Parkinson-White syndrome, occurs when an additional pathway for signals is formed in the heart. This means that electrical signals can jump over the atrioventricular node, the part of the heart that helps control your heart rate.

When the electrical signals jump over this node, your heart can beat extremely fast. This results in an arrhythmia called paroxysmal supraventricular tachycardia.

In some cases, this syndrome has been passed down through families. But most people who develop this disease do not have a family history. Additionally, for many people with this syndrome, the cause is unknown. A few cases are the result of mutations in the PRKAG2 gene.

Arrhythmogenic right ventricular dysplasia

This rare disease is above all a structural problem. If you have this disease, a genetic mutation causes the muscle cells in your right ventricle, the lower chamber of the heart, to die. The disease mainly develops in people under the age of 35.

Arrhythmogenic right ventricular dysplasia usually develops without any symptoms. But it can still cause irregular heartbeats and even sudden death, especially during exercise. In later stages, this condition can also lead to heart failure.

About half of all cases of arrhythmogenic right ventricular heart failure are familial. Autosomal dominant inheritance from a parent is the most common. But it can also be passed on as an autosomal recessive gene from both parents. At least 13 genetic mutations have been linked to this disorder. PKP2 appears to be one of the most frequently affected genes.

The genes that cause this disease are responsible for forming desmosomes, or structures that connect muscle cells in the heart to each other. When these cells are not formed properly, the cells that make up the muscles in your heart cannot connect or communicate signals with each other.

Idiopathic ventricular fibrillation

There is a lot of uncertainty around the cause of idiopathic ventricular fibrillation. Many people diagnosed with this disease have survived cardiac arrest with ventricular fibrillation and no other obvious cause. A genetic cause has been proposed in a 2016 study, but research is ongoing.

“Idiopathic” means that the origins of a condition are unknown. As genetic testing for other familial arrhythmias improves, it appears that cases of idiopathic ventricular fibrillation are decreasing.


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