Atrial flutter: definition, causes, symptoms, diagnosis and treatment
Atrial flutter is a cardiac arrhythmia that can occur in the atria, characterised by frequent contractions, irregular heartbeat and sudden onset. Depending on the mode of onset, two forms of atrial flutter can be distinguished: a paroxysmal form, with abrupt, short-lasting episodes, and a permanent form
The causes of the disorder may be physiological in nature, may be due to underlying pathologies or may depend on external factors.
The diagnosis of atrial flutter is based on a thorough cardiological examination that includes an electrocardiogram. Its treatment may vary from patient to patient.
What is atrial flutter?
Atrial flutter is an alteration in cardiac rhythm that originates in the atrium and can spread to the ventricle, affecting cardiac output and blood circulation; given its area of onset, it is classified as an ectopic supraventricular arrhythmia.
Episodes of atrial flutter are characterised by an irregular heartbeat with frequent contractions and accelerated pulsations; flutter means ‘rapid heartbeat’, and patients affected by this condition may have a heart rate of more than 200 beats per minute (bpm).
Two forms of atrial flutter can be distinguished: a paroxysmal form and a permanent form
Paroxysmal atrial flutter: the paroxysmal form is characterised by a sudden onset of attacks, which are usually of short duration.
The heart rate of a patient suffering from atrial flutter can be as high as 120/180 beats per minute, but the episodes usually end within a few hours, or a few days at most.
This type of disorder affects healthy individuals, who may experience isolated attacks, and therefore does not usually require drugs or other therapeutic interventions.
Permanent atrial flutter: In the permanent form, the development of the disorder is often gradual.
However, in this case the disorder may last for years and be synonymous with an associated pathology; due to its latent nature, the diagnosis of atrial flutter is often not immediate and the condition may go undetected.
Specific targeted therapy is usually required to treat this condition.
Atrial flutter and atrial fibrillation: characteristics and differences
The characteristics of atrial flutter are similar to those of atrial fibrillation, but flutter differs from the latter in that the changes in the heartbeat are less pronounced and have a different impact on the ventricles: in fact, while atrial fibrillation can lead to an increase in the heartbeat of up to 400 bpm, during a flutter the heartbeat rate can rise to a maximum of 240-300 bpm.
This also means that, compared to fibrillation, the beat is less disordered, as a reduced frequency results in fewer contraction impulses.
Generally speaking, during these arrhythmias, a blockage is established at the level of the atrioventricular node, which stops part of the impulses directed towards the ventricle; this occurs particularly during atrial flutter, so much so that in subjects affected by this condition, the ventricular contraction can be as much as ¼ of the atrial contraction.
In fact, flutter is distinguished as 2:1, 3:1 or 4:1, indicating that only one out of every 2, 3 or 4 stimuli manages to pass through the block.
This is an extremely important detail, as it is often the case that the flutter goes unnoticed for this very reason.
Sometimes the patient may experience both flutter and atrial fibrillation: these are quite serious cases, which require special attention from doctors.
What are the symptoms
Patients suffering from atrial flutter may present with different symptoms, which may vary depending on the form of the disorder: in general, the paroxysmal form presents more evident symptoms with more intense attacks, but it is the disorders due to the permanent form that pose the most serious risk to the patient.
The main symptoms of atrial flutter include:
- Palpitation or heart palpitation;
- Angina pectoris or chest pain;
- Dyspnoea or breathlessness;
- Asthenia or weakness;
The symptoms of atrial flutter should not be underestimated, as one of the most serious complications induced by this disorder is the sufferer’s predisposition to develop an ischaemic stroke.
This is because the frequent irregular contractions of the heart muscle tend to adversely affect cardiac output and impair blood circulation, leading to a high probability of forming thrombi that can travel to the brain and prevent proper cerebral irradiation.
The causes of atrial flutter are numerous and can be of a different nature.
As in the case of fibrillation, one of the main causes is the presence of heart disease.
Among non-pathological causes, the circumstances that can trigger the onset of atrial flutter are:
- Alcohol abuse;
- Drug taking;
- Anxiety states;
- Excess caffeine or other exciting substances;
- Side effects of drug therapies;
How to diagnose atrial flutter
As already mentioned, because of its characteristics, the diagnosis of atrial flutter is by no means simple and often this condition can go undetected for a long time, despite the patient undergoing clinical examinations: for this very reason, it is necessary to consult an expert cardiologist, who will carry out a thorough analysis of the heart’s state of health and prescribe targeted tests.
During a cardiologist’s examination, the most suitable test to detect any arrhythmia or atrial flutter is the electrocardiogram; in some cases, the cardiologist may also prescribe a dynamic electrocardiogram according to Holter, for monitoring over an extended period of time.
Therapy and treatment of the disorder
The most suitable therapy for treating atrial flutter or other cardiac arrhythmias varies considerably from case to case.
What influences treatment is first and foremost the type of disorder, depending on whether it is a paroxysmal or permanent atrial flutter; any associated pathologies and the subject’s general health conditions may also influence the choice of therapy.
In general, if it is a paroxysmal flutter there are two main intervention strategies:
- Pharmacological therapy: the patient may be given digital drugs to slow the heart rhythm, or an antiarrhythmic treatment may be prescribed; these drugs are also indicated for maintenance therapy and to prevent further flutter episodes;
- Electrical treatment: cardioversion is a non-invasive therapeutic procedure that uses an electric shock to restore sinus rhythm in patients suffering from cardiac arrhythmias;
- Permanent atrial flutter, on the other hand, often indicates the presence of other heart diseases or pathological disorders of a different nature; for this reason, both general therapy to treat the underlying condition and specific therapy to treat atrial flutter are required.
The latter generally involves:
- Anticoagulants to prevent the formation of thromboembolic phenomena;
- Transcatheter radiofrequency ablation; this is a particular, more invasive intervention strategy, which, thanks to the insertion of a catheter led up to the heart, is able to generate a radiofrequency electric discharge, hitting the myocardial area responsible for the arrhythmic phenomenon. The area affected by the discharge is thus destroyed, restoring the regular number of impulses sent by the sinoatrial node.