(Also known as: Heart rhythm disorders, irregular heartbeat)

An arrhythmia is a disorder that affects the normal heart rate. With an arrhythmia, the heart tends to beat too slow (bradycardia), too fast (tachycardia), or irregularly. These disorders can affect the amount of blood pumped by the heart.

The heartbeat is controlled by electrical impulses that normally travel on a smooth path through the heart, causing the ventricles and atria to contract in a specific order, pushing blood through the lungs and body. These electrical impulses are controlled by the heart’s sinoatrial (SA) node, or sinus node, the heart’s natural pacemaker.

Although many arrhythmias will never cause health problems, they can cause troublesome symptoms, such as dizziness or chest discomfort. Other, more dangerous arrhythmias can impact blood supply and require medical management. Left untreated, they can eventually lead to stroke, heart attackheart failure, or sudden death.

Atrial fibrillation (afib) is the most common arrhythmia. Different types of atrial fibrillation may last for seconds or be permanent. The condition is more common in older people and can have many different causes.

Ventricular fibrillation is the most dangerous type of arrhythmia. With this condition, the heart’s ventricles lose the ability to contract, stopping blood flow to the body and brain. Ventricular fibrillation rapidly leads to loss of consciousness and death, and requires electrical shock (defibrillation) to restart the heartbeat.



There are numerous arrhythmias, commonly known as an irregular heartbeat, of which the most common abnormal rhythm that doctors diagnose is atrial fibrillation. Various types of atrial fibrillation may last for a short time or be a permanent condition. Symptoms such as general fatigue, dizziness, chest discomfort, and shortness of breath can indicate a heart condition which you should have assessed by a professional doctor. Arrhythmias affect the amount of blood that your heart can pump around your body. While some conditions often don’t lead to more severe problems, you should ensure that you are monitored and treated by a qualified cardiologist.



A doctor will review your symptoms, medical history, perform a physical exam, and carry out one or more diagnostic tests to confirm atrial fibrillation.

  • Electrocardiogram: An ECG is a non-invasive test that can confirm an AF diagnosis. This test records your heart's rhythm and electrical activity by attaching sensors to the outside of your body. The sensors are connected to a machine that detects tiny electrical signals that make your heart pump blood around your body. It is a harmless and painless procedure.

  • Holter monitor: This test requires patients to wear a small, portable ECG for between one and two days. It is performed when an ECG test for an AF diagnosis is inconclusive or to assess how well your condition is controlled. You can wear the machine around your shoulder or waist while electrodes are attached to your chest. The monitor will record your heart rate and rhythm over a few days and, therefore, will provide your medical team with more information about your condition.

  • Event recorder: If you don’t get AF symptoms very often, your doctor may request an event recorder. This monitor is used over two to four weeks to record your heartbeat during times when you experience symptoms such as dizziness, blackouts, chest pain or palpitations.

Other diagnostic tools include an implantable loop recorder, blood tests, and an echocardiogram.


There are various treatment options for atrial fibrillation, such as cardioversions and medication. If these treatments fail to control your symptoms, your doctor may recommend an ablation.

  • It interrupts your heart’s abnormal electrical circuit: This procedure uses a catheter to destroy a small area in the heart that is causing an irregular rhythm. Pulmonary veins are often the leading cause of AF, so an ablation will target the area between each of the veins and the left atrium of your heart. However, depending on your type of AF, your doctor may also target other areas.

  • Your doctor will guide a long thin tube to your heart: Your doctor will guide a catheter through your groin and up to your heart using an x-ray camera. Radiofrequency or cryoablation from the tip of the tube will block the electrical signals in your heart that are causing an abnormal rhythm. This procedure is minimally invasive compared to open-heart surgery.

  • Your recovery time is fairly quick: Some patients may need to stay overnight, while others can go home on the same day as the procedure. While you may notice a slight soreness or discomfort, it should last no longer than a week, and most patients can return to doing their normal activities a few days after catheter ablation.



At South Island Heart, we provide premium cardiology services for various conditions. We offer short wait times for consultations and competitively priced services so that you can receive excellent care when you require it. Our resident cardiologist, Dr Krys Milburn, has extensive experience and provides a high standard of care when treating cardiac patients. Dr Milburn focuses on clinical and interventional cardiology with minimally invasive treatment options. Contact us for a consultation with a cardiologist that you can trust.