Ever felt your heart going too fast and wondered what was going on? When your heart starts beating too fast, at a rate of more than 100 beats per minute it’s known as tachycardia. So how does this happen? Your heart has two sides, a left side and a right side. And both sides have an upper chamber known as atrium which collects blood that’s coming back to the heart and a lower chamber known as the ventricle which pumps blood away from the heart to other parts of the body. This pumping is regulated by an electrical current which starts in your sinoatrial node and spreads through your atria causing it to contract and squeeze blood into your ventricles. The electrical impulse then travels to the atrioventricular node which connects to your ventricles like a wire and sends the electrical signal to both of your ventricles simultaneously and causes them to contract.1 If these normal electrical pathways of your heart get disrupted then it can cause your heart to beat irregularly. Some people don’t experience any symptoms when they have tachycardia. When symptoms are felt they can include palpitations, feeling dizzy or light headed, shortness of breath, fatigue, and chest pain.2 There are three main kinds of tachycardia classified according to the part of the heart where they originate ¬– atrial or supraventricular tachycardia, ventricular tachycardia, and sinus tachycardia. Let’s take a look at some of the factors which can cause these abnormally fast heart rate:
Causes Of Atrial Or Supraventricular Tachycardia
If you have atrial or supraventricular (which means above the ventricles) tachycardia then it means that there are issues with the electrical signals in the atria or upper chambers of your heart which is causing it to beat excessively fast. This results in a reduced blood flow to other parts of your body as your heart’s unable to pump blood effectively. There are many kinds of atrial tachycardia – a common kind that you might be familiar with is atrial fibrillation – with each kind causing the irregular heart rate in a manner that’s slightly different. Most of them however occur because of the presence of extra electrical pathways between your atria and ventricles.3 Let’s take a look at factors that can cause or trigger atrial tachycardia:4
1. Wolff-Parkinson-White Syndrome
Wolff-Parkinson-White syndrome is a congenital condition which causes your heart to beat faster. People with this syndrome have an additional electrical connection due to which electrical signals in the heart can bypass the normal pathway and essentially form a short circuit. This causes signals to go round in a loop over and over making the heart beat really fast. These episode usually occur arbitrarily though they can sometimes be trigged by consume excessive amounts or caffeine or alcohol or by intense exercise.5
2. High Blood pressure
High blood pressure can damage your heart’s electrical system resulting in atrial fibrillation.6 Lifestyle factors like consuming too much sodium or alcohol, and not engaging in sufficient physical activity can lead to high blood pressure. Medical conditions like sleep apnea, chronic kidney disease, and thyroid problems that can impact levels of sodium and hormones in your blood may also increase your blood pressure.7
3. Coronary Heart Disease
Coronary heart disease is a condition where plaque builds up in the arteries of the heart which bring oxygen rich blood to heart muscles. This can make your arteries stiff and narrow, reduce the flow of blood, and over a period of time, weaken heart muscle and cause irregular heart beats.8 Factors like smoking, high cholesterol, high blood pressure, high blood sugar etc. have a role to play in the development of this condition.9 10
4. Lifestyle Factors
In people who are prone to supraventricular tachycardia various lifestyle factors can sometimes trigger them.11
Caffeine
Caffeine which is found in coffee, tea, chocolate, and most cola drinks can increase your risk of supraventricular tachycardia.
Alcohol
Your chances of having irregular heart rhythms increase when you’re consuming alcohol. In fact, during the late 70’s the term “holiday heart syndrome” was used to describe people with atrial fibrillation who experienced heart palpitations after drinking excessively. According to one study, people who have atrial fibrillation have about 4.5 times higher chance of having an episode when they’re consuming alcohol than when they’re not.12
Smoking
Smoking has also been found to trigger a fast heart rate. Various mechanisms may be at work here ¬– for instance, we know that smoking can make your arteries stiff, raise your blood pressure, and is a risk factor for coronary heart disease.13
5. Medications
Certain medications can also cause this condition. Examples include high levels of digoxin which is a heart medicine, theophylline which is a lung medicine, decongestants with stimulants, some diet pills that are sold over the counter etc.14 Illegal stimulants like methamphetamine and cocaine can also cause a rapid heart rate.15
6. Medical Conditions Which Reduce Oxygen In The Blood
Multifocal atrial tachycardia, a kind of supraventricular tachycardia which is mostly seen in senior people over the age of 50 occurs with conditions which lower oxygen levels in your blood like:
Bacterial pneumonia: which is a respiratory condition that develops due to bacterial infection in your lungs. You can get this condition when an infection in your nose, sinuses etc. spreads to your lungs or if you breathe bacteria directly into your lungs.16
Chronic obstructive pulmonary disease: which is a lung disease that makes it difficult for you to breathe. This condition is mostly caused by smoking.17
Congestive heart failure: which is a condition where your heart is unable to pump sufficient blood to the rest of the body. Coronary artery disease and uncontrolled high blood pressure are the most common causes of this condition. But other heart conditions like congenital heart disease, weak heart muscles due to infection etc. can also cause this condition. As can health issues like an overactive or underactive thyroid, severe anemia etc.18
Lung cancer: which is cancer that starts in your lungs. Smoking is the leading cause of this kind of cancer though people who don’t smoke can also develop lung cancer.19
Pulmonary embolism: is a block in an artery in your lungs. These are most often caused by blood clots though fat droplets, air bubbles etc. may also cause them.20 21
Causes Of Ventricular Tachycardia
Ventricular tachycardia is a condition where issues with electrical signals in your ventricles make your heart beat faster which affects its capacity to pump blood to other body parts. In some cases, it is not possible to know what causes this condition but underlying heart conditions are often responsible. Some causes of ventricular tachycardia include:
1. Heart Conditions
In most cases ventricular tachycardia is caused by some kind of heart condition. This can include:
Heart Attack
Ventricular tachycardia can develop as a complication of heart attack. Scar tissue may develop in ventricle muscles days or years after an attack and result in ventricular tachycardia.
Cardiomyopathy
Cardiomyopathy is a term used for disorders of your heart muscle, where the walls of the chambers of the heart become thickened, stretched, or stiff. This may happen due to high blood pressure, inflammation of the heart muscle due to a viral infection, drug use, vitamin or mineral deficiencies, heavy alcohol consumption, a problem with the heart valve, a genetic mutation which increases your vulnerability, or a disorder of the vessels or tissues such as sarcoidosis, Wegener’s granulomatosis, muscular dystrophy, amyloidosis, polyarteritis nodosa, lupus, or vasculitis. It can also sometimes occur as a pregnancy complication.22
Myocarditis
Myocarditis is a rare disorder that causes inflammation of your heart muscle. It’s generally caused when an infection reaches your heart. These infections are usually caused by viruses like coxsackievirus, influenza virus, cytomegalovirus, parovirus, adenovirus etc. Bacterial infections like streptococcus, Lyme disease, chlamydia , and mycoplasma, as well as reactions to certain medicines, for instance, drugs used in chemotherapy, or exposure to certain chemicals from the environment can also cause this condition.23
2. Genetic Conditions
Rarely ventricular tachycardia can be caused by such inherited disorders like long QT syndrome and Brugada syndrome which affect the way the electrical signaling system of your heart works.
3. Medications
Some medications including those used to treat irregular heart rhythms can cause ventricular tachycardia. Decongestants, diet pills, herbal remedies which contain ephedra or ma huang, ad illegal drugs like cocaine may also be responsible for them.24
4. Imbalances In Your Blood
Low potassium levels as well as other electrolyte imbalances may lead to ventricular tachycardia.25
5. Sarcoidosis
Sarcoidosis is an illness that causes inflammation. This is usually seen in your skin, lungs, or lymph nodes though any organ can be affected. The cause of sarcoidosis is unknown.26 27 28
Causes Of Sinus Tachycardia
Sinus tachycardia occus when your sinoatrial node which is your heart’s natural pacemaker sends out abnormally fast electrical signals. This can be your body responding to stressors like extreme emotional distress, fever, anxiety, fright, or intense exercise. In some cases, this can happen inexplicably, a condition which is known as “inappropriate sinus tachycardia”.29 30 Sinus tachycardia can also sometimes be caused by:
1. Anemia
A condition where you have a low red blood count which means that your blood is unable to carry sufficient oxygen to the rest of the body
2. Hemorrhage
A condition where you experience excessive blood loss.
3. Hyperthyroidism
A condition where your thyroid gland makes too much thyroid. This can be caused by Graves disease or an inflammation of the thyroid because of certain medications, viral infections, or post pregnancy. Taking excessive amounts of thyroid hormone, non cancerous growths in the pituitary or thyroid gland as well as tumors in the testes or ovaries can also cause this condition.31 32
What Can You Do About It?
The treatment for tachycardia varies according to its cause. It can include:
Lifestyle Changes
Healthy habits like reducing stress, consuming less alcohol or caffeine, getting sufficient sleep, and quitting smoking can be helpful.
Treatment For Medical Conditions
As we saw a variety of health issues can cause tachycardia and treating these will take care of the abnormal heart rhythm too. For instance, fever can be treated with medicines to bring down the temperature, or antibiotics in case it’s caused by a bacterial infection. Blood loss is treated with intravenous fluids and blood transfusions before the injury which caused it is dealt with. Hyperthyroism is treated with antithyroid medication, surgery, or radioactive iodine and conditions that affect the lung like pneumonia or pulmonary embolism are usually treated with appropriate medications.
Treatment For Cardiac Conditions
Treatment for cardiac conditions which cause tachycardia depend on the condition. The treatment depends on the cause of the arrhythmia. Some people respond to massage of the carotid sinus which is present in the neck, others require medicines which slow down the heart rate. In some cases, you might need a surgical procedure known as radiofrequency catheter ablation which destroys small part of the heart which are causing electrical problems. Electrical cardioversion, a process where an electrical shock is delivered to restore the normal rhythm of the heart is also used to treat tachycardia.33 34
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