10 Causes Of Arrhythmia (Irregular Heartbeat) You Must Know

causes of arrhythmia

Whether it’s a sudden racing, skip, or fluttering, an irregularity in your heart’s rhythm can be quite worrying. So what could it mean and what causes it?

What Is Arrhythmia?

The heart’s rhythm is regulated by electrical signals controlled by the sinus node, the natural pacemaker present in your heart. Electrical impulses travel smoothly through the chambers of the heart, making them contract in a particular order so that blood is pushed through your body. Any problems in this process can cause an arrhythmia, which is an abnormal heart rhythm where your heart beats too quickly, too slowly, or irregularly. Symptoms also include dizziness, shortness of breath, fainting, and palpitations.


While these abnormalities may mean nothing more than some minor discomfort or inconvenience in some cases, they can also have fatal consequences other times. Which is why you need to trace the cause and deal with it promptly. Here’s a look at the factors that can cause an irregular heart rhythm.1

Causes Of Arrhythmia (Irregular Heartbeat)

1. Heart Conditions

Many conditions that damage your heart can result in an irregular rhythm.


Coronary Artery Disease

Coronary artery disease (CAD) is a condition where plaque builds up in the arteries which carry blood to your heart. This narrows the arteries and reduces the flow of blood. Blood clots can also develop in the arteries if you have this condition. These can then block the flow of blood to the heart and lead to heart attacks. Some factors that increase your risk for CAD include smoking, obesity (particularly abdominal fat), high blood pressure, diabetes, excessive stress, lack of exercise, depression, and high cholesterol levels.

You may not experience any symptoms in the early stages of the condition but, eventually, symptoms associated with a heart attack like shortness of breath, nausea, loss of consciousness, sweating, chest pressure, pain in the chest, neck, arm, or jaw, as well an irregular or racing heartbeat may be felt.2


Heart Attack

You have a risk of developing an irregular heartbeat if the tissue in your heart has been damaged by a previous heart attack. Meanwhile, an ongoing heart attack is the most common cause of the most dangerous kind of arrhythmia – ventricular fibrillation. The lower chambers of the heart twitch uncontrollably in this condition and it can cause a person to suddenly collapse or lose consciousness.

Symptoms like chest pain, nausea, dizziness, an irregular heartbeat, and shortness of breath can occur within the range of a few minutes to an hour before the affected person collapses. Call for emergency medical help if you see this happening. Start cardiopulmonary resuscitation (CPR) by doing chest compressions in the middle of the chest while waiting for help. A machine called an external defibrillator can help restart the heart.3 4


Heart Valve Disease

Your heart has four valves, one located at the exit of each of the four chambers of the heart. They help regulate the flow of blood through the chambers and close after blood enters a chamber, to stop it from leaking backward. The heart has four valves, each located at the exit of one of the heart’s four chambers.

As the heartbeat pushes blood through the heart, the valves close after blood has entered the chamber to prevent it from leaking backward. But if you have heart valve disease, a valve may not open or close properly. This can be a congenital condition or maybe due to normal wear and tear. Conditions like CAD, high blood pressure, a previous heart attack, or cardiomyopathy which can thicken or scar heart tissue may also contribute to heart valve problems. Infections like endocarditis which affects the lining of your heart or rheumatic fever may also damage the valves.


In some cases, you may not experience any symptoms with heart valve disease but a heart murmur may be heard when a stethoscope is used. Symptoms, when experienced, can include pain or pressure in the chest, shortness of breath particularly while lying down or exercising, dizziness, weakness, and swelling of ankles, feet, or stomach in addition to a racing heartbeat.

Do keep in mind though that the severity of the symptoms is not related to the severity of the condition and some people who only experience mild symptoms may need urgent treatment to prevent damage to the heart.5


Congenital Heart Disease

A congenital heart defect is a structural problem in the heart that is present at birth. This can involve the valves or walls of the heart or the arteries and veins near it. Some defects may be minor and not cause any problems while others can cause blood flow to slow down, travel to the wrong place or in the wrong direction, or get completely blocked. Some genetic disorders like Down’s syndrome are linked to congenital heart defects. Meanwhile, conditions like rubella or uncontrolled diabetes during pregnancy as well as the use of certain prescription medications can result in congenital heart defects in babies.

Some additional common symptoms of congenital heart defects in adults include tiredness, shortness of breath particularly when exercising, a heart murmur, swelling in the extremities, and a blue tinge on the skin, lips, or nails.6



Cardiomyopathy is a disease that affects the muscles of the heart. The heart muscles may get stretched and become too thin, become abnormally thick or too stiff, or get replaced by fat or scar tissue. This can lead to arrhythmia, as well as blood clots, heart failure, or heart attacks. And many factors like CAD, congenital heart disease, chronic high blood pressure, bacterial or viral infections of the heart, excessive alcohol, use of drugs like cocaine, chemotherapy, radiotherapy, nutritional deficiencies, complications due to pregnancy etc. can cause his condition.

You may not experience any symptoms initially if you have cardiomyopathy. As the condition worsens, you can expect symptoms like abnormal heart rhythms as well as shortness of breath, tiredness, chest pain, dizziness, fainting, and swelling of your ankles, feet, legs, hands, or stomach.7

2. High Blood Pressure

High blood pressure, increased pressure in the arteries which carry blood from the heart, can cause your heartbeats to become irregular. A systolic pressure (the pressure exerted when your heart is beating) greater than or equal to 140 mmHg and/or a diastolic pressure (the pressure exerted when your heart is at rest between beats) greater than or equal to 90 mmHg constitutes high blood pressure. High blood pressure can affect various parts of your body including your heart, brain, and kidney, and even lead to a heart attack or stroke.

High blood pressure is generally caused by a narrowing of your arteries. Factors like being overweight, excessive consumption of alcohol, excessive salt intake, stress, and lack of exercise can up your risk of high blood pressure. Certain medical conditions like kidney disease, sleep apnea, and hormone disorders can also cause high blood pressure.

In most cases, high blood pressure doesn’t cause any symptoms, which is why it’s known as a “silent killer.” In severe cases, you may experience symptoms like an intense headache, fatigue, shortness of breath, vomiting, and vision problems.8

3. Diabetes

Diabetes is a condition where your blood sugar levels are abnormally high. This develops because your body cannot either produce enough insulin or use it effectively to stimulate the absorption of glucose. High sugar levels in the blood can increase fatty deposits on the walls of your arteries over time, causing arteries to narrow and eventually develop CAD. High cholesterol, high blood pressure, obesity or having an elevated waist circumference, obstructive sleep apnea, polycystic ovary syndrome etc. can up your risk of diabetes.

Diabetes can cause symptoms like excessive thirst, fatigue, blurred vision, frequent urination, unusual hunger, and weight loss. However, sometimes you may not experience any symptoms.9 10

4. Genetic Disorders

Some genetic disorders can cause your heart to have an irregular rhythm.

Catecholaminergic Polymorphic Ventricular Tachycardia

This is a rare genetic disorder where the proteins that regulate the release of calcium in your heart don’t function properly. This can cause an increase in the level of calcium in your heart, which leads to problems with electrical signaling. The most common symptoms of this condition are palpitations, dizziness, and blackouts. These can be triggered by intense emotions or even exercise.11

Brugada Syndrome

Brugada syndrome is another genetic disorder that affects the way the electrical system of the heart functions. It can cause your heart to beat exceedingly fast. Many people with this condition don’t experience any symptoms but you may still see symptoms like palpitations, seizures, blackouts, chest pain, dizziness, and breathlessness. These symptoms may sometimes be triggered by excessive consumption of alcohol, dehydration, or a high temperature.12

Long QT Syndrome

This is a genetic condition where your heart muscle takes extra time to recharge between beats. This condition can cause chaotic rapid heartbeats. Seizures and blackouts are common symptoms caused by this condition. Sometimes, in people with this syndrome, the heart can beat abnormally fast, starving the brain of oxygen and causing the affected person to pass out. Usually, the rhythm goes back to normal in about a minute and the person then regains consciousness. But, in some cases, the abnormal rhythm continues and leads to ventricular fibrillation. These episodes can be triggered by stress, intense exercise, a slow heart rate while sleeping, a sudden sound, or intense exercise, especially swimming. However, they can also occur without a trigger.13

Short QT Syndrome

In people who have short QT syndrome, the heart muscle recharges in a shorter time than usual between beats. This can cause symptoms like fainting and dizziness and lead to cardiac arrest.14

If you have a family member who suffered a sudden cardiac death, it’s a good idea to get screened for genetic disorders that might cause abnormalities in the rhythm of your heart. If you’re found to carry the genetic condition, preventive treatments like medication and implantable devices may be recommended.15

5. Thyroid Disorders

Both hyperthyroidism, where your thyroid gland produces too much thyroid, and hypothyroidism, where your thyroid levels are too low, can result in arrhythmias. Many conditions can result in hyperthyroidism. These include Graves’ disease, tumors in the ovaries or testes, noncancerous growths in the pituitary or thyroid gland, inflammation of thyroid after pregnancy. Infections and some medicines like lithium and interferon alpha can also be responsible.

Some common symptoms of this condition are palpitations, fatigue, trouble concentrating, a visibly enlarged thyroid gland, increased appetite, hair loss, hand tremor, increased sweating, nervousness, weight loss or gain, and trouble sleeping.16

Meanwhile, hypothyroidism is mostly caused by your immune system mistakenly attacking and damaging your thyroid gland or by treatments for thyroid cancer, or an overactive thyroid. Iodine deficiency, viral infections, and some medications used to treat depression, bipolar disorder, arrhythmias, certain cancers, hepatitis C etc. can also be the cause. Symptoms like weight gain, depression, tiredness, muscle aches, sensitivity to the cold, as well dry hair and skin can indicate hypothyroidism.17

6. Alcohol

Consuming excessive alcohol may result in irregular heartbeats. Limit your consumption to one or two drinks a day if you’re a man and one drink a day if you’re a woman. A drink translates to 4 ounces of wine, 12 ounces of beer, or 1/5th of an ounce of 80-proof spirits.18

7. Caffeine

Excessive consumption of caffeine can cause your heart to beat irregularly. It’s not recommended to have more than 400 mg of caffeine in a day. Pregnant women should either avoid it or restrict consumption to 300 mg in a day. For your reference, an 8-ounce cup of coffee has around 95 to 200 mg of caffeine.19

8. Smoking

Smoking can damage your heart and cause irregularities in your heart rhythm.

9. Drugs And Supplements

Many medications, including some used for treating heart problems, blood pressure, depression, and psychosis, can cause irregular heart rhythms. So can certain dietary supplements and recreational drugs. Your doctor will be able to tell you if any medication or supplement you’re on has this side effect.20

10. Stress

Stress doesn’t just affect your mind, it can cause physical issues like arrhythmia. In fact, you would’ve noticed that you experience symptoms like tense muscles, a pounding heart, or sweating when you experience stress. These effects usually pass once the problem that’s causing you stress is resolved. However, a constant state of stress can be harmful and can cause headaches, dizziness, muscle pain, trouble sleeping, and tiredness. Regular exercise, a healthy diet, getting enough sleep. taking a break, mindfulness meditation, and calming breathing exercises can be helpful if you’re grappling with stress.21

What To Do If You Have An Arrhythmia

If symptoms of arrhythmia persist or you have a history of sudden unexplained death in your family, do see a doctor. Your doctor may monitor your heartbeat using devices like a Holter monitor or event monitor or ask for an electrocardiogram, a test that measures your heart’s electrical activity. Depending on the diagnosis, medication, surgery to remove heart tissue causing the arrhythmia, or implantation of a pacemaker may be recommended.

Lifestyle changes like stopping smoking, limiting the consumption of caffeine or alcohol, lowering stress, increasing physical activity (under a doctor’s direction), and maintaining a healthy weight can also be helpful as they can impact underlying medical conditions as well as target arrhythmias directly.22