Some people with tachycardia may have no symptoms or complications. It may, however, significantly increase the risk of stroke, sudden cardiac, and death.
Tachycardia refers to a high resting heart rate. A resting adult heart generally beats between 60 and 100 times per minute. When an individual has a fast heartbeat, the upper or lower chambers of the heart beat significantly faster.
When the heart beats too rapidly, the pumping is less efficient and the flow of blood to the rest of the body, including the heart, is reduced. As a result, the muscles of the heart or myocardium need more oxygen because of the quicker beating of the heart. If the condition persists, it could lead to the death of oxygen-starved myocardial cells, leading to a heart attack.
The human heart has four chambers:
- Atria – The heart has two upper chambers – the left and the right atria
- Ventricles – The heart has to lower chambers – the left and the right ventricles
The heart has a sinus nude, its natural pacemaker, which is located in the right atrium. It produces electrical impulses. Each impulse causes an individual heartbeat.
The electrical impulses depart the sinus node and proceed across the upper chambers, which results in the contraction of the atria muscles. The contraction of the atria muscles pushes blood into the ventricles.
The electrical impulses proceed to the atrioventricular node, which is a cluster of cells. The AV node slows down the electrical sends them after to the ventricles.
By delaying the electrical signals, the AV signals and node gives the ventricles time to fill with blood first. When the muscles of the ventricle receive the electrical signals, they contact, pumping blood either to the lungs or the rest of the body.
When a problem occurs with the electrical signals, it could result in a faster-than-normal heartbeat. The individual has a fast heartbeat or tachycardia.
It is normal for the heart rate to rise during a workout or as a physiological response to trauma, stress, or illness. But in tachycardia, the heart is beating faster than normal in its upper or lower chambers, or both while resting.
Types of tachycardia
There are various types of abnormal fast heartbeat, classified according to origin and cause. Common types of fast heartbeat or tachycardia include:
- Atrial fibrillation – It is a rapid heart rate due to irregular and chaotic impulses of the atria. The signals result in uncoordinated, rapid and weak contractions of the upper chambers or atria. Atrial fibrillation may be temporary, but will not end unless it is treated. Most people with atrial fibrillation have some structural abnormalities of the heart, usually caused by high blood pressure or heart disease. Hyperthyroidism, a disorder of the valve, or heavy alcohol use may cause the problem.
- Atrial flutter – This condition has the heart beating very fast but at a regular rate. This is often the result of weak contractions of the upper chambers or atria. It is often caused by irregular circuitry within the atria. It usually resolves by itself but there are times when it needs treatment.
- Supraventricular tachycardia – It is an abnormally fast heartbeat originating somewhere above the ventricles. It is usually caused by abnormal circuitry in the heart, usually starting from birth. It creates a loop of overlapping signals.
- Ventricular tachycardia – It is a rapid heart rate originating from abnormal electrical signals in the ventricles. The rapid heart rate prevents the ventricles from filling up and contacting efficiently to pump enough amount of blood to the body.
- Ventricular fibrillation – It occurs when chaotic and rapid electrical impulses cause the ineffective quivering of the ventricles instead of pumping blood to the body. It can be fatal if the normal heart rhythm is not restored within minutes using an electric shock to the heart – defibrillation. It usually occurs during or after a heart attack.
Symptoms of fast heartbeat or tachycardia
A heart that beats too fast may not pump blood effectively to the rest of the body, depriving organs and tissues of oxygen and causing the following symptoms:
- Shortness of breath
- Rapid pulse rate
- Chest pain
- Heart palpitations
Some people with tachycardia manifest no symptoms, and the condition is discovered only during a heart-monitoring test or physical examination.
Tachycardia or fast heartbeat is generally caused by a disruption in the electrical impulses that control the pumping action of the heart. The following conditions, situations, and illnesses are the possible causes:
- Congenital abnormalities of the heart
- A reaction to certain medications
- Consumption of cocaine and other recreational drugs
- Consuming too much alcohol
- Heart disease resulting in poor blood supply and damage to heart tissues, such as heart valve disease, coronary artery disease, heart muscle disease, heart failure, infections, and tumors.
- An overactive thyroid gland
- Certain lung diseases
- Electrolyte imbalance
Sometimes, the exact cause of the tachycardia cannot be identified.
Diagnosis and Treatment
A thorough physical exam, testing, and medical history are required in diagnosing tachycardia.
To diagnose your condition and identify the specific type of tachycardia, your doctor needs to evaluate your symptoms, ask about your medical history and health habits, and conduct a thorough physical examination.
Several tests may be necessary to diagnose your tachycardia.
An electrocardiogram is the most common tool used in diagnosing tachycardia. The test is painless as it detects and records the electrical activity of your heart using small sensors attached to your arms and chest. The device records the strength and timing of electrical signals traveling through your heart. Your doctor will look for patterns among those signals to determine the type of tachycardia you have and how heart abnormalities may contribute to the fast heart rate.
This test will confirm the diagnosis or pinpoint the location of problems in the heart’s circuitry. During the test, the doctor will insert catheters tipped with electrodes into your arm, neck, or groin and guides them through your blood vessels to different spots in your heart, precisely mapping the spread of electrical impulses during each beat. This can identify any abnormality in the circuitry.
Heart imaging may be performed to check for structural abnormalities affecting blood flow, which may contribute to tachycardia. The types of cardiac imaging that the doctor may use include:
- Echocardiogram – Using sound waves, it creates a moving picture of the heart. It identifies abnormal heart valves, poor blood flow, and heart muscle that does not work normally.
- Magnetic resonance imaging – It provides still or moving pictures of the blood flow through the heart, detecting irregularities.
- CT scan – It combines several X-ray images to provide a detailed cross-sectional view of the heart.
- Coronary angiogram – Using dyes and special X-rays, it shows the inside of your coronary arteries.
- Chest X-ray – It takes still pictures of the heart and lungs, detecting if the heart is enlarged.
The doctor will test your heart functions while it works hard during exercises or when medication is given to make it beat faster.
Tilt table test
In this test, you will lie flat on a special table. The table will be tilted as if you were standing up, with the doctor observing your heart and nervous system respond to changes in position.
Different treatment options are depending on the cause of the condition, the general health and the age of the person with tachycardia, and other factors.
Treatment aims to address the cause of the condition. When clinically applicable, the doctor may attempt to slow down the rate, prevent subsequent episodes, and reduce the risk of complications of tachycardia.
In cases where there is no underlying cause, the doctor may try out different therapies.
The vagal nerve helps in regulating the heartbeat. Maneuvers such as heaving, coughing, or placing an ice pack on the person’s face may regulate the heartbeat.
The administration of antiarrhythmic drugs, orally or by injection, can restore a normal heartbeat.
Patches or paddles will be used to deliver an electric shock to the heart. This will affect the heart’s electrical impulses and restore normal rhythm.
Some measures can prevent the heartbeat from becoming too fast.
- Radiofrequency catheter ablation – Electrodes at the end of a catheter inserted into the heart via blood vessels ablate the small sections of the heart that is responsible for the abnormal heartbeat.
- Medications – Anti-arrhythmic medication, taken regularly, can prevent tachycardia
- Implantable cardioverter-defibrillator – It is a device surgically implanted into the chest to continuously monitor the heartbeat.
- Surgery – This procedure involves removing a section of tissues or the creation of a pattern of scar tissue, which is a bad conductor of electricity.
- Novel oral anticoagulants or blood-thinners – They make it harder for the blood to clog to lower the risk of developing a stroke or a heart attack.
Risks of Having Fast Heartbeat
Any condition that puts a strain on the heart or damages the tissue can increase the risk of tachycardia. The following are the factors that may increase the risk of having tachycardia:
- Heart disease
- Sleep apnea
- High blood pressure
- Overactive or underactive thyroid
- Heavy caffeine use
- Heavy alcohol use
- Use or recreational drugs
- Psychological stress or anxiety
Other risk factors include:
- Older age
- Family history
When to Seek Medical Attention
Several conditions can cause a rapid heart rate and the symptoms of tachycardia. It is important to immediately get an accurate and prompt diagnosis, and appropriate care. You should see your doctor immediately if you or your child experiences any symptoms of tachycardia.
If you have difficulty breathing or have chest pain that lasts more than a few minutes, get emergency medical care.
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