Causes, Symptoms and Treatment of Arrhythmia
Arrhythmia is when the heart rhythm is irregular in some way, or if the heartbeat is either too fast or too slow. In most cases, arrhythmia is nothing to worry about, although sometimes it can be very serious, leading to damage to the brain and other organs due to lack of blood supply.
In order to understand the condition it is worth knowing more about how the heart actually does its job. The heart has four chambers – the left and right atrium and the left and right ventricle. The ventricles are below the atria.
The heart beats in two main stages known as diastole and systole. The systole stage can be further split up into atrial systole and ventricular systole. In the diastole stage, all four chambers of the heart relax and start to fill up with blood. In the next step – atrial systole – an electrical signal generated by the sinoatrial node (SA node) in the right atrium causes the two atria to contract and pump blood into the ventricles.
The electrical signal is then transmitted to the atrioventricular (AV) node between the atria and ventricles, and then goes down to the ventricles via a path known as the bundle of His. This initiates the last part of the cycle (ventricular systole) where the ventricles contract and pump blood out to the lungs and the rest of the body.
It is faults in the electrical signaling described above which result in arrhythmia and inappropriate coordination or spacing of the contractions lead to reduced blood supply to the rest of the body.
Fast Facts about Arrhythmia
- Arrhythmia is an irregular or abnormally slow or fast heartbeat
- You may experience a mild form of arrhythmia known as premature beats, which takes the form of short-lived palpitations after strenuous exercise or drinking too much caffeine
- There are many other kinds of arrhythmia, the more serious forms of which include atrial fibrillation and Wolff-Parkinson-White syndrome
- Symptoms of serious arrhythmia include constant palpitations, chest pain, dizzy spells, fainting, breaking out in a sweat, shortness of breath, anxiety and even a “full” sensation in the throat or neck
- The most common method used to diagnose arrhythmias is electrocardiography (EKG) but there are many other methods
- Lifestyle changes will control symptoms for many people but if necessary, arrhythmias can be treated with drugs, medical procedures (e.g. pacemaker implants, cardioversion or catheter ablation) or by surgery such as coronary artery bypass grafting
Types of Arrhythmia
There are several main kinds of arrhythmia:
- Premature beats. This is the term given to arrhythmias where extra beats occur, either in the atria or ventricles. Symptoms include fluttering or feeling that your heart has skipped a beat, although there may not be any symptoms at all. Premature beats are the type of arrhythmia related to consuming too much caffeine or nicotine, or over-exercising.
- Tachycardia (a heart rate that is too fast). Specific types include ventricular tachycardia and paroxysmal supraventricular tachycardia (PSVT). PSVT is a type of tachycardia where electrical signals travel to from the atria to the ventricles as they should, but re-enter the atria and cause extra heartbeats. Alternatively there may be an extra signaling path from the atria to the ventricles – this type of PSVT is known as Wolff-Parkinson-White syndrome and is very serious.
- Bradycardia (a heart rate that is too slow)
- Fibrillation, i.e. very fast, irregular heartbeat. Atrial fibrillation (AF) is the most common kind – in fact, it is the most common of the serious arrhythmias. Rather than starting in the SA node, the electrical signal begins elsewhere and travels too fast and in a haphazard way, causing the walls of the atria to quiver rather than beating properly. This can result in blood clotting and hence stroke or heart failure.
- Flutter. Atrial flutter is the most well-known type. It is similar to atrial fibrillation in terms of symptoms, but the electrical signals are regular rather than irregular.
Other Names for Arrhythmia
- Bradyarrhythmia (another term for bradycardia or slow heart rate)
- Atrial flutter
- Atrial fibrillation
- Ventricular arrhythmia
- Ventricular fibrillation
- Ventricular tachycardia
- Heart block, though often considered as a separate type of arrhythmia
- Long QT syndrome
- Sinus node dysfunction
- Wolff-Parkinson-White syndrome (a type of PSVT)
- Torsades de pointes (a type of ventricular fibrillation)
- Accessory pathway tachycardia and AV nodal reentrant tachycardia (both types of PSVT)
Common Causes of Arrhythmia
Some types of arrhythmia can be caused by excessive use of stimulants (including caffeine, cocaine and amphetamines), alcohol abuse, smoking and certain kinds of medication – including (ironically) some kinds of antiarrhythmic agents. Emotional stress, strenuous physical activity and electrolyte imbalance can also be a trigger.
Arrhythmia may also be caused by other heart conditions such as hypertension (high blood pressure) and coronary heart disease, or by thyroid disorders.
Certain congenital heart problems are associated with particular types of arrhythmia including long QT syndrome and Wolff-Parkinson-White syndrome.
Risk Factors for Arrhythmia
Serious arrhythmias like atrial fibrillation are more likely to affect you if you’re over sixty, particularly if you’re on medications including beta blockers, appetite suppressants and certain drugs used to treat thyroid conditions or asthma.
You are more at risk of developing arrhythmia if you have or have had a condition that weakens the heart, such as coronary heart disease, faulty heart valves, a congenital heart disorder, hypertension, heart attack (myocardial infarction), cardiomyopathy or an infection of the heart.
People with a family history of arrhythmia are at greater risk.
Symptoms of Arrhythmia
If symptoms occur, they may include palpitations and the feeling that your heart has missed a beat. This is nothing to worry about if it only occurs after specific events such as strenuous exercise or if you’ve had a stressful experience.
However, if you have constant palpitations this may be the sign of serious arrhythmia. Other possible symptoms include chest pain, dizzy spells, fainting, breaking out in a sweat, shortness of breath, anxiety and even a “full” sensation in the throat or neck.
Initially your doctor will want to know about any symptoms you might be having, plus details of medications you’re on and any possible family history of heart disease. He or she may also take your pulse, listen to your heart with a stethoscope and examine your legs/feet for signs of swelling.
To confirm a diagnosis of arrhythmia, other tests must be carried out. The most important and commonly used of these is the electrocardiogram (EKG), which monitors the electrical activity of the heart throughout the heartbeat cycle and produces a graph that shows whether the heart is beating irregularly or too fast or too slow.
The standard EKG is a one-off test that will only detect arrhythmia if it occurs during the test. Since arrhythmia often comes and goes, a technique known as stress testing may be used in combination with the standard EKG. During a stress test, you do some vigorous exercise or take a drug in order to make your heart beat faster. Alternatively you may be asked to wear or carry a monitor (known as a Holter monitor or event monitor) all the time. The Holter monitor records your heartbeat continuously, while the event monitor is only used when you experience symptoms.
Another type of device to detect abnormal heart rhythms – an implantable loop recorder – can be inserted surgically under the skin. This is useful for people who don’t experience symptoms very often, as it can be left in place for up to two years.
Other tests that may be carried out include blood tests, echocardiography, chest X-ray, and coronary angiography (a type of X-ray involving a contrast dye).
If you are already known to have serious arrhythmia you may be given a test known as an electrophysiology study, which involves inserting a wire into a vein and threading it up to your heart, where it can be used to record electrical signals and even trigger arrhythmia by stimulating the heart electrically, so that antiarrhythmic drugs can be tried out to see if they work.
If you suffer from fainting spells, a tilt table test can be used in combination with EKG.
Treatment Options for Arrhythmia
There are several treatment routes: medication, non-surgical medical procedures, and full-on surgery.
Suitable medications include beta blockers and calcium channel blockers (both of which slow the heart rate down) and digoxin. You might also be given anticoagulants and antiplatelet agents such as warfarin or aspirin.
Medical procedures include cardioversion or insertion of a pacemaker (both of which involve applying an electrical current to the heart), and catheter ablation. Pacemakers are used to treat various kinds of arrhythmias including bradycardias, which don’t respond well to drugs. Cardioversion may be used to treat atrial fibrillation or flutter. Catheter ablation involves inserting a catheter into a blood vessel – often the femoral vein in the upper thigh or the jugular vein in the neck – and then threading it towards your heart. When the end of the catheter reaches the correct spot, radiofrequency energy (radio waves) are emitted through it in order to scar (ablate) the cells that are responsible for causing the arrhythmia.
There is also a system of exercises known as vagal maneuvers which can be effective for people with some types of arrhythmia.
Surgical options for treating arrhythmia include coronary artery bypass grafting (if coronary heart disease is what’s causing your arrhythmia), or a technique known as maze surgery which involves making small incisions or burns in the atria to control the electrical signaling there.
Prevention of Arrhythmia
There are no guaranteed methods of preventing arrhythmia although you can reduce the risk of premature beats by controlling or eliminating your intake of stimulants and minimizing stress levels.
Coping with Arrhythmia
- Mild forms of arrhythmia like premature beats are common and harmless
- Even if you have a more serious form of arrhythmia, you can still lead a normal life provided you take any medication as directed and inform your doctor if you get any side effects or new symptoms
- Learn how to take your pulse
- Give up smoking, cut down your alcohol intake and avoid illicit drugs
- Eat a healthy diet with plenty of fresh fruit and vegetables, wholegrains, fiber, pulses and “good” proteins such as lean meat and fish. Avoid too much sodium, sugar and saturated or trans fat
- Try relaxation techniques and learn to avoid things that increase your stress/anger levels
- It’s worth discussing vagal maneuvers with your doctor but they don’t work for everyone
Where to Get More Information: American Heart Association