Heart Rhythm Disorders

Dr Riyaz Somani is a specialist in the branch of cardiology called electrophysiology. An electrophysiologist is an expert at treating patients with heart rhythm abnormalities.

If you’re experiencing symptoms of palpitations, a regular or irregular rapid heart rate, breathlessness, chest pain, dizziness, general tiredness and weakness or blackouts, then you can book an appointment with Dr Somani for specialist advice and care.

What is an Abnormal Heart Rhythm?

At rest the heart usually beats between 60-100 times per minute. Electrical impulses keep the heart beating steadily like a clock. That’s why we call the heart your “ticker”.

When the heart fails to keep it’s rhythm, it’s because something has disturbed these electrical impulses, resulting in the heart beating faster, slower, or irregularly.

In cardiology, we call it arrhythmia.

Symptoms of Arrhythmia

Some people with arrhythmia may not experience any symptoms at all but when symptoms do occur they can be quite broad and may include one or more of the following:

  • Palpitations – pounding or fluttering in your chest
  • Tiredness and weakness
  • Dizziness
  • Feeling like you might faint or actually blacking out
  • Breathlessness
  • Chest pain or pressure

In more severe cases, arrhythmia could cause collapse or rarely cardiac arrest.

How is Arrhythmia Diagnosed?

If you or your GP suspects you have an arrhythmia you should be referred to a specialist with an interest in arrhythmia which can be an important step in helping to diagnose the specific type of abnormality. Arrhythmia can present differently in each patient. Dr Somani will take a full history of your symptoms and a full medical examination at your initial consultation before recommending appropriate investigations to confirm the diagnosis.

Further tests will depend on the suspected diagnosis but may include:

  • Routine blood tests, including checking salts in the blood and thyroid function.
  • A tracing of the heart – Electrocardiogram (ECG).
  • A heart monitor (for between 24-hours and up to 2 weeks) to wear at home.
  • An ultrasound scan of the heart – Echocardiogram.
  • An exercise treadmill test for palpitations provoked during/after exercise.
  • An implantable loop recorder – a small monitor can be implanted under the skin on the left side of the chest – useful to diagnose symptoms that occur infrequently.

Common conditions that cause arrhythmia

Atrial fibrillation (AF) – irregular heart rhythm

Atrial fibrillation is the most common form of heart rhythm disorder. It results in the heart beating irregularly and quite often too quickly. (Over 100 beats per minute at rest).

Whilst atrial fibrillation is not usually life threatening, it is important to see a specialist if you begin to experience symptoms or if AF is suspected. AF can be associated with an increased risk of stroke and can lead to a deterioration in heart function in some patients.

If you are diagnosed with atrial fibrillation, Dr Somani will carefully assess your overall risk of stroke and provide clear instructions and treatment to reduce this risk. In addition, there are various treatments available for AF including medication, cardioversion (delivering a controlled shock to the heart to ‘stun’ the heart back into normal rhythm), cardiac ablation procedures such as pulmonary vein isolation (PVI) to specifically target areas in the heart where AF arises from and by doing so restoring a normal heart rhythm, and occasionally implanting a pacemaker.

A single lead electrocardiogram (ECG) showing an irregularly irregular heart rhythm, which is characteristic of Atrial Fibrillation (AF).

A 3D map of the left atrium and pulmonary veins during an ablation procedure for Atrial Fibrillation. The red and blue balls represent ablation lesions delivered to target the pulmonary veins.

A single lead electrocardiogram (ECG) showing Atrial Flutter with the characteristic sawtooth pattern. This common arrhythmia can give rise to high heart rates and palpitations.

A 3D map of the right atrium during an ablation procedure for Atrial Flutter. The red balls represent ablation lesions delivered to target the atrial flutter circuit.

Atrial Flutter

This is the second most common arrhythmia, often occurring due to a ‘short circuit’ in the top right chamber (right atrium) of the heart. It usually results in a rapid heart rhythm and is also associated with a risk of stroke. Atrial flutter differs from Atrial fibrillation in that it often results in a rapid and regular heartbeat, whereas atrial fibrillation usually causes a more chaotic and irregular heartbeat.

Once the diagnosis has been confirmed on an ECG, the treatment options are also very similar to those for atrial fibrillation and include assessment and treatment to reduce the risk of stroke, medication to slow the heart rate or to prevent recurrence, cardioversion to ‘stun’ the heart back into a normal rhythm or a specific type of cardiac ablation procedure to target the ‘short circuit’ within the right atrium. Occasionally a pacemaker may be recommended if other treatments have not been successful at restoring the heart’s normal rhythm.

Ventricular tachycardia (VT)

Ventricular tachycardia is a heart rhythm disorder that arises in the lower chambers of the heart (ventricles) causing the heart to beat too quickly. When this happens, your atria don’t have time to send enough blood into the ventricles before they contract again, which affects the volume of blood being pumped around your body.

Ventricular tachycardia is more common in people with existing heart conditions or damage from previous heart disease although certain types of VT can occur in patients with a heart that is otherwise normal. If you’re experiencing symptoms, or if VT is suspected, then it’s important to be assessed by an expert.

A single lead electrocardiogram (ECG) showing a rapid broad regular heart rhythm characteristic of Ventricular Tachycardia (VT).

A 3D map of the Left Ventricle in a patient suffering with Ventricular Tachycardia (VT). The red balls represent ablation lesions successfully delivered to target scar from where the VT was arising from.

A single lead electrocardiogram (ECG) showing a single ventricular ectopic beat (5th beat). This is also known as a premature ventricular contraction (PVC) or ventricular ectopic (VE).

Ventricular ectopics

Ventricular ectopic beats are common, and are caused by extra beats in the heart outside of your normal heart rhythm. This can feel like a fluttering or pounding sensation or even a feeling that the heart has skipped a beat. This is because the heart rhythm resets after an ectopic beat, resulting in a short pause between beats.

If ectopic beats occur infrequently, then they are often benign and unlikely to be dangerous. Ectopic beats can lead to more serious problems if frequency of the ectopics is excessive or if there is underlying heart disease or an underlying heart condition. Most people with ectopic beats experience minimal symptoms and may not require  treatment. However, it is important to exclude any underlying cardiac abnormalities  and if symptoms are present, seeing a specialist may be helpful to allow a full assessment and to discuss treatment options.

Supraventricular Tachycardia (SVT) – fast regular heart rhythm

If you regularly experience periods where the heart suddenly beats much faster than normal at rest, you may be experiencing SVT.

SVT is not life threatening, but it can be uncomfortable and painful and may also cause dizziness and breathlessness. SVT can be tricky to diagnose as it often occurs intermittently and may be infrequent and the symptoms can sometimes be mistaken for anxiety or panic attacks. If the diagnosis is confirmed following appropriate investigations, SVT does not always need treatment, and sometimes lifestyle changes may be all that is required.

Treatment will depend on how intrusive the symptoms are but can include medication or procedures such as catheter ablation to target the precise area in the heart responsible for the arrhythmia.

A single lead electrocardiogram (ECG) showing a rapid regular heart rhythm characteristic of Supraventricular Tachycardia (SVT).

A single lead electrocardiogram (ECG) showing a pause in the heart rhythm which may lead to symptoms of dizziness or blackouts.

Bradycardia – slow heart rate

Generally, we consider a heart rate below 60 beats per minute as slow. However, it does depend on your age, fitness, medication and other factors that could mean a resting heart rate of below 60 beats per minute is normal for some people. Bradycardia may be caused by the heart’s own natural pacemaker not functioning appropriately or due to possible ‘wear and tear’ of the heart’s natural conduction system (wiring).

Ultimately, if the heart rate is too slow, it may result in a reduction in blood flow to other organs and this in turn may cause some patients to experience some of the symptoms described at the top of this page. Common symptoms include unsteadiness, weakness, a reduction in exercise capacity, tiredness, dizziness, breathlessness and blackouts.

Treatment for bradycardia is not always required and may simply be resolved by adjusting existing medication. However, seeing a specialist  is important to identify the cause and receive treatment if required. Bradycardia may require treatment with implantation of an artificial  permanent pacemaker.

Pacemakers & ICDs

Here is a selection of images that show the kinds of different devices that may be used to treat heart rhythm disorders. 


Pacemaker implanted visible beneath the skin

Diagram of pacemaker inside the body

Micra leadless pacemaker

Micra leadless pacemaker

Medtronic ICD Device