Ectopic beats

Table Of Contents

1. What is Ectopic Beats?

Ectopic beats are also known as Ectopic Heart Rhythm or cardiac ectopy. It is produced when the heart creates a premature beat, usually followed by a brief pause.

Types of Ectopic Beats

There are specifically two types of ectopic heart beats. They are:

1. premature ventricular contraction (PVC), or ventricular ectopics (VE),

This single lead electrocardiogram (ECG) shows a single ventricular ectopic beat (6th heart beat). This is also know as premature ventricular contraction (PVC) or ventricular ectopics (VE).

2. premature atrial contraction (PAC), or supraventricular ectopy (SVE)

This single lead electrocardiogram (ECG) shows 3 beats of atrial ectopy which occur in a flurry of rapid heart beats lasting under 3 seconds, before resumption of normal heartbeat. These beats are also know as premature atrial contraction (PAC) or supraventricular ectopy (SVE), or atrial ectopic beats.

You may have come across these terms when looking at the results of a 24 Holter or electrocardiogram (ECG),or been informed that you have ectopic beats by your doctor.

Premature ventricular contraction (PVC) originates from the ventricles or the lower chambers of the heart are the main pumping chambers of your heart.

Risk factors for PVC include ageing, past history of heart attack, cardiomyopathy (heart muscle weakness), or valvular heart disease, usually due to mitral valve prolapse or a floppy mitral valve.

However, if you are fit and well without any of these risk factors, the most common cause of PVCs are PVCs that arise from the outflow tract which can be from the right (RVOT) or left (LVOT) ventricular outflow tracts.

PACs are premature heart beats originate from the heart’s upper chambers or atria. PACs are usually considered harmless, but if they occur repeatedly in a continous manner, then you may be at risk of developing atrial fibrillation (AF), which is when there is continuous irregular PACs which occur continuosly for more than 30 seconds at a time.

Occasionally, we experience an ectopic beat when we exercise, are stressed or consume stimulants such as coffee. However, if it persists, medical practitioners investigate the underlying cause of such irregular beats. This may be due to heart disease or injury or an electrolyte imbalance in the blood

2. Causes of Ectopic Beats

Other Causes of ectopic heart beats include:

• Excessive alcohol consumption
• Excessive caffine consumptionPrescription drugs
• Stress (which produces high adrenaline levels)
• Exercise
• Diarrhoea and vomitting, which may disturb electrolyte levels (typically low potassium levels)
• Heart muscle damage from a heart attack
• Heart enlargement (cardiomyopathy)
• Valvular heart disease, such as a floppy mitral valve (mitral valve prolapse)

3. Signs and Symptoms of Ectopic Beats

You may feel the following:

• Palpitations or as if your heart is pounding
• Occasional forceful heart beats
• Faintness or dizziness
• Hyper awareness on your heartbeat
• Chest discomfort (short-lived lasting 1 or 2 seconds only coincident with the ectopic beat)

Sometimes, you may feel no symptoms at all.

4. Diagnostic Investigations of Ectopic Beats

Following these are performed to pinpoint the causes of irregular heart rhythms:

• Physical Exam: Your doctor may be able to detect occasional uneven beats, including a rapid/quick heartbeat, followed usually by a compensatory pause. Blood pressure is often normal.
• Electrocardiogram (ECG): This is performed to record the electrical activity of the heart using electrodes placed on the chest’s surface. Your doctor may sometimes record a prolonged ECG lasting 2 minutes, whilst asking you to take deep breaths, to try to capture these ectopic beats “live” on the ECG, in order to accurately diagnose your condition. ECG test is useful for Cardic Screening or Cardic Monitoring.
• Holter monitoring: a monitoring device worn 24 to 48 hours that records your heart rhythm. It is important that you write any symptoms down in a diary, so that your doctor can analyse the ECG monitor at the precise time that you experience symptoms, in order to make a diagnosis.
• Echocardiography: a test that uses ultrasound (high frequency sound waves) to create images of the heart to explore the heart’s structure and function.

Other tests include:

• Stress Test
• Cardiac Magnetic resonance imaging (MRI)
• Heart CT Scan
• Coronary angiography

5. Ectopic Beats Treatment

If possible, avoiding the triggers of ectopic beats is also key in reducing its incidences as most ectopic beats need not to be treated. However, your doctor might ask you to avoid excessive alcohol and caffeine.

Your doctor might suggest regular physical activity if you are inactive. If the triggers are related to stress, self-help methods such as meditation or mindfulness or other relaxation therapies might help.

However, if ectopic heart beats persist and are bothersome, treatment is based on the underlying cause based on the tests performed.

Reassurance

In most cases where the cause of ectopy are minimal PVC or PAC – usually quantified as < 1% on 24h Holter monitoring, then most patients can be safely reassured. With reassurance, and breaking the cycle of panic and anxiety, which in turn releases adrenaline, triggering further ectopy, patients can experience a significant improvement in symptoms.

Drugs

Your doctor may consider a trial of drugs such as:

1. Beta-blockers – these are of “anti-adrenaline” drugs which serve to calm the flight or fright response, which may be useful in minimising ectopy. Examples include bisoprolol, metoprolol and atenolol, and most drugs ending with “…lol”
2. Calcium channel blockers – these block calcium channels in the cardiac cells, which may lead to reduction in ectopy.
3. Flecainide – this is a specialist drug which should be prescribed by a cardiologist with an interest in heart rhythm disorders (electrophysiologist)
4. Amiodarone – this is a drug which may be very effective in treating most arrhythmias, but which may have a long term side effect profile including abnormal thyroid function, liver function, skin sensitivity to sunlight and lung abnormalities. It may be useful for acute / immediate treatment of heart rhythm abnormalities. Howver, if prescribed, be sure to check the duration of this prescription.

Catheter ablation

Rarely, if the ectopy burden is significant (typically more than 10% , or 10,000 ectopic beats out of the typical 100,000 normal heart beats in a day), with significant symptoms which continue despite medication and reassurance, a catheter ablation procedure may be performed.
Other indications for ablation include:

1. Ventricular tachycardia from the outflow tract (right ventricular outflow (RVOT) or left ventricular outflow tract (LVOT).
2. Significant deterioration in pump function (usually determined on echocardiogram) due to frequent ectopics seen
3. Intolerance of symptoms or drugs

In a catheter ablation procedure, small electrical wires are inserted through a keyhole approach in your groin, and these are advanced into your heart. You are usually awake, and given sedation and local anaethetic for this procedure.

The source of ectopic beats are mapped precisely in the heart using X-ray and modern 3D mapping equipment (electroanatomical mapping), which can then be targeted using radiofrequency (burning) to cauterise the area in the heart which cause ectopy.

The procedural success rates are usually above 80% for this procedure, and complications include 3% risk of groin bruising, 1% risk of pericardial effusion (small collection of fluid around the heart), and <0.5% risk of cardiac perforation leading to emergency surgery. The risk of stroke and heart attack is < 0.5%.

Prognosis (Outlook)

Minor infrequent ectopic or skipped beats beats which do not cause any other symptoms can usually be safely ignored and treated with reassurance and avoidance of triggers.

If your catheter ablation is succesful, you can usually come off all drugs and be discharged from your doctor, as this is likely to be a curative procedure, with a low risk of recurrence.

Top 3 signs which may indicate that you need urgent assessment and treatment

1. Ectopic beats which are continuous and rapid, which lead to acute shortness of breath, chest pain or dizziness
2. Sudden blackout, or loss of consciousness
3. Worsening long-term shortness of breath

Have you ever felt significant symptoms of palpitations/skipped beats? Contact Dr. Lim, voted best cardiologist in London and an expert in palpitations, for a thorough assessment, including state-of-the-art diagnostics, and comprehensive treatment plan.