Arrhythmia
What is arrhythmia?
Arrhythmia refers to a condition associated with an irregular heartbeat. Often arrhythmias occur in normal functioning hearts. It is quite common for them to be benign, and, in many cases, they are described as nothing more serious than a heart flutter or abnormal heartbeat. But, they can cause some uncomfortable symptoms, which affect the quality of life, and can lead to serious heart conditions.
Arrhythmias are assessed by cardiac electrophysiologists. Factors such as the patient’s symptoms and clinical situation are taken into account when formulating the most suitable treatment option.
Types of arrhythmia
There a number of types of arrhythmia. These include:
- Arrhythmia - When the heartbeat is irregular, or if it originates in an area of the heart other than the sino-atrial node, it is called arrhythmia.
- Bradyarrhythmia - Bradyarrhythmia is a heart rhythm that is too slow. When the heart’s rhythm is too slow to meet the metabolic demands of the body, you may experience symptoms like shortness of breath, dizziness and fainting. Your cardiologist may recommend a pacemaker for bradyarrhythmia.
- Tachyarrhythmias - Tachyarrhythmias occur when electrical impulses are generated in an area of the heart other than the sino-atrial node, and the heart beats too fast. These arrhythmias sometimes occur in normal functioning as well as abnormal hearts. Symptoms of a tachyarrhythmia include heart palpitations, chest pains, shortness of breath, dizziness and fainting. If the tachyarrhythmia originates in the atria, it is known as a supraventricular. If the tachyarrhythmia originates in the ventricles, it is known as ventricular tachycardia.
Supraventricular tachyarrhythmia or atrial arrhythmiascan be categorised into four types. These are:
- Atrio-ventricular nodal re-entry tachycardia
This condition occurs when electrical impulses move in a self-perpetuating and abnormal manner (also known as a circus movement) in and around the atrioventricular node. This kind of arrhythmia can often be treated with prescription medication, but in some cases, your cardiologist may recommend a heart ablation procedure. In this case, a cardiac electrophysiologist will perform the procedure. The heart ablation procedure has a success rate of around 95 per cent.
- Atrioventricular re-entry tachycardia and Wolf-Parkinson White syndrome
This type of arrhythmia occurs when electrical impulses move in a self-perpetuating and abnormal manner (also known as a circus movement) between the atria and the ventricles. The condition typically occurs when there is an extra electrical connection (known as an accessory pathway or bypass tract) between the atria and the ventricles. If electrical impulses move from the atria down the AV node to the ventricles and then use the bypass tract to move from the ventricles to the atria, a particular movement known as the orthodromic-ventricular tachycardia occurs between the atria and ventricles. This kind of movement can be reversed. In this case, the electrical impulses move along the bypass tract from the atria to the ventricles and subsequently use the AV node to move from the ventricles to the atria. This movement is called antidromic atrioventricular tachycardia. Atrial fibrillation that conducts impulses to the ventricles by means of the accessory pathway is known as pre-excited atrial fibrillation. This disorganised atrial arrhythmia can lead to malignant arrhythmia, which can be treated with medication, but in some cases, your cardiologist may recommend a heart ablation procedure. - Atrial flutter
Atrial flutter can be either sporadic (also known as paroxysmal) or persistent and last for days or weeks at a time. In some cases, the condition can be permanent. Symptoms of atrial flutter vary but often include heart palpitations, shortness of breath, dizziness and fainting. The condition can cause an enlarged left ventricle, which increases the risk of heart failure. Typical atrial flutter, the most common kind of atrial flutter, occurs in the right atrium. Your cardiologist may prescribe anticoagulants for this condition in order to decrease the risk of stroke, heart disease, and other conditions. In some cases, a rate versus rhythm strategy may form part of your treatment plan. If you choose a rhythm strategy, a heart ablation procedure may be recommended, as it is generally a favourable alternative to medication. Typical atrial flutter can occur alongside both atrial defibrillation and atypical atrial flutter. This may only become evident weeks, months or years after an atrial flutter ablation procedure. Atypical atrial flutter can also be treated with heart ablation and electro-anatomical mapping, although the success rates are not as high.
- Atrial fibrillation
Atrial fibrillation occurs when there is chaotic electrical activity in the atrium, causing an irregular heartbeat. It is a common and persistent type of arrhythmia. When atrial fibrillation occurs, the sinus node is not the primary impulse generator, and abnormal electrical impulses move via the AV node to the ventricles causing irregular ventricular rates.
Heart flutter
Sometimes atrial fibrillation is an indication that there is an underlying condition such as ischemic heart disease, cardiomyopathy, vascular heart disease and heart failure. Sometimes, atrial fibrillation can occur in normal hearts as a result of any of the following factors:
- Over-active thyroid
- Too much caffeine
- Exercise
- Sleep
- Obesity
- Obstructive sleep apnoea
Atrial fibrillation can also occur alongside atrial flutter, which will need to be treated.
Atrial fibrillation can be sporadic (also known as paroxysmal) or persistent and last for days or weeks, or in some cases, the condition can be permanent. Symptoms of this condition include:
- Heart palpitations
- Shortness of breath
- Fatigue
- Dizziness
The condition can also lead to an enlarged ventricle and heart failure.
Your cardiologist may prescribe anticoagulants for this condition in order to decrease the risk of stroke and other conditions. There are a number of anticoagulants available, including those that require regular monitoring and new oral anticoagulants (NOAC) that do not need to be monitored. Ask your doctor about the benefits of each type of medication and help you find one, which can be tailored to your needs.
Depending on your symptoms and the severity of your condition, your cardiologist may recommend a treatment plan, which includes a rate versus rhythm strategy. As part of the rate control strategy, your medication will enhance the function of the AV node. In the rhythm strategy, the sinus rhythm will be maintained with medication that includes an AV nodal blocking agent.
In some cases, your cardiologist may recommend an atrial fibrillation ablation procedure, the aim of which is to decrease the impact of atrial fibrillation and the need for large amounts of medication and improve quality of life. During the procedure, the pulmonary veins are separated from the atrial tissue.
