Treating atrial flutter

Atrial flutter is an arrhythmic condition of the heart where there is very rapid electrical circuit which originates in the right atrial chamber which leads to desynchronisation of the heartbeat between the top (atrial) and bottom (ventricles) chambers of the heart. In this article, renowned consultant cardiologist and electrophysiologist Dr Boon Lim explains how atrial flutter occurs, and what treatment options are available.

What is atrial flutter?

The heart beats due to the transmission of electrical impulses, facilitating the muscular contraction and release, which keeps the blood flowing constantly into the heart, through its chambers, and then off to the rest of the body.

With atrial flutter, there is an error with the electrical impulses, and the top right atrium begins to beat faster than normal, nearly five times the typical rate (300 bpm as compared to 60 – 90 bpm). This causes desynchronisation with the ventricles, which receive blood after the atria, which are typically at 100 – 150 bpm. In all, the effect is that the heart is less efficient and a patient with this condition can be at risk of strokes due to the pooling of blood and the opportunity for blood clots to form, which can break off and make their way into the brain.

Atrial flutter may be in itself a symptom of an underlying heart condition, such as:

Cardiomyopathy
Coronary heart disease
Valvular disease
Hypertension (high blood pressure)
Myocarditis
Congenital heart disease
Atrial flutter can also be related to a pulmonary or respiratory condition like chronic obstructive airway disease (COPD) and obstructive sleep apnoea (OSA).

What are the symptoms of atrial flutter?

Not all patients will have outward symptoms of atrial flutter, but others may experience:

A consistent and rapid heart rate
Tightness, heaviness, or pain in the chest
Feeling faint (syncope)
Periods of intensified heart rate (palpitations)
Fatigue
Shortness of breath (dyspnoea)

How is atrial flutter diagnosed?

Atrial flutter can present very similarly to other arrhythmias, particularly atrial fibrillation, so it is important to get a reading and map of the heart’s electrical activity in order to correctly diagnose the ailment.

This can include tests and scans such as:

Blood tests to check hormone levels and rule out possible contributing factors, like the thyroid
Chest x-rays to check on the physical structure of the chest and its organs
Echocardiograms, which are a type of ultrasound that can be used to detect structural heart abnormalities which may pre-dispose to atrial flutter
Electrocardiograms (ECGs), which record the heartbeat pattern. This is one of the most utilised and efficient ways to diagnose arrhythmias. An atrial flutter on an electrocardiogram will appear with what is referred to as a ‘sawtooth’ pattern. In some cases, the EGC can be conducted over several days (between 24 and 73 hours), thanks to a smaller device called a Holter monitor, which is worn on the shoulder or around the waist. This helps to contextualise the arrhythmia and doctors decipher if there is anything else to the pattern, and if there are any particular triggering activities.
Mobile ECG devices, which are typically consumer grade devices (think Apple Watch, or Kardia Mobile), which can record an ECG; there is a caveat though, which is on a simple 2 lead ECG recorded by the device, it may not be possible to be definitive about a diagnosis of atrial flutter (but your electrophysiologist should be able to identify arrhythmia, and suggest further test to confirm a diagnosis of atrial flutter). The key points which would indicate flutter rather and fibrillation is the regularity of the rapid heart rhythm recorded. In typical cases of atrial flutter, there is often a high sustained fixed heart rate (say 150bpm) rather than the chaotic random irregularly irregular heartbeat which characterises atrial fibrillation.

How is atrial flutter treated?

Treatment for atrial flutter seeks to recalibrate the heartbeat and to decrease the patient’s risk of stroke. The first consideration (which you should speak to your GP about immediately), is your risk of stroke. Those at higher risk are those who are:

Are older than 65 (higher risk >65 if female)
Have congestive heart failure, diabetes, or vascular disease
Have high blood pressure (hypertension)
Have had previous strokes or transient ischaemic attacks

If you have any of these risk factors, your doctor is likely to start you on an anticoagulant. This is usually a direct oral anticoagulant (DOAC) with some examples of these being edoxaban, rivaroxaban, apixaban and dabigatran. Patients are rarely given warfarin nowadays, which is a fairly old anticoagulant drug which is more inconvenient, needed frequent blood checks of warfarin levels to arrive at the correct dosing. These anticoagulants are given to minimize the risk of stroke.

Another class of drugs may also be given which are called antiarrhythmic drugs. These are usually a beta blocker (such as bisoprolol or metoprolol) or calcium blocker, such as verapamil or diltiazem. The aim of these drugs is to slow down the heart rate.

Other options include a cardioversion, which aims to restore normal heart rhythm with an electrical shock delivered whilst under a short duration general anaesthetic.

However, the definitive treatment for atrial flutter is catheter ablation, which is typically performed in an hour under general or local anaesthetic, requires a small incision into the thigh to allow access to the femoral vein through which a catheter will be passed towards the heart (aided by 3D mapping or X-ray scans). Once the catheter is located in the appropriate area in the right atrium, radiofrequency energy is emitted to cauterise part of the tissue that allows the flutter circuit to exist. Once the area (termed cavo-tricuspid isthmis or CTI) is ablated, flutter can no longer continue, and the cure rate is typically in excess of 95% success, with a small risk of complications (<1% typically) of vascular damage in the groin, fluid build up around the heart (pericardial effusion) or inadvertent damage to AV node needing a pacemaker.

See this video for a 3D illustration showing how a catheter ablation for flutter is performed.

At Top Doctors, we find the best electrophysiologist (heart rhythm doctors) who are all able to assist with diagnosing and treating atrial flutter and other heart rhythm abnormalities. Contact Dr Lim today regarding your heart rhythm issues.