Atrial fibrillation and atrial flutter are common abnormal heart rhythms (arrhythmias) which cause the upper chambers of the heart (atria) to beat too fast. The heart rhythm in atrial flutter is more regular and less chaotic than is seen with atrial fibrillation. Atrial fibrillation (AFib) is significantly more common than atrial flutter. These two arrhythmias can occur together or independently of one another. Atrial flutter, which is sometimes referred to as A flutter or aflutter, can occur in athletes but is uncommon in this population in the absence of other risk factors.
Atrial flutter symptoms can include palpitations (sensation of the heart a flutter), decreased exercise tolerance, shortness of breath, fatigue, chest pain and lightheadedness. Many of these symptoms are due to the elevated A flutter heart rate. As with atrial fibrillation, atrial flutter can cause blood clots to form in the heart which leads to a stroke. A flutter treatment focuses on managing the abnormal rhythm and decreasing risk of stroke, heart failure and other complications.
Atrial flutter is a type of arrhythmia which is caused by abnormal electrical signals that originate in the atria. These rapid, regular electrical signals override the heart’s internal pacemaker and cause the heart to beat too fast, often 100 to 150 beats per minute. Atrial flutter diagnosis is made with a cardiac rhythm monitor such as an electrocardiogram (EKG).
There are 2 types of atrial flutter, typical atrial flutter and atypical atrial flutter. Typical atrial flutter originates in the right upper heart chamber. Atypical flutter can come from either the left or right atria. In both typical and atypical atrial flutter, an abnormal electrical circuit causes the repeated, rapid beating of the atria. The electrical circuit creates its own circular pattern of stimulation. This means that once atrial flutter gets started, it often continues until something interrupts the electrical circuit. Electrical cardioversion, medications, or an ablation procedure can be used to revert the heart to sinus rhythm. Catheter ablation is a minimally-invasive procedure which creates scar lines in the heart to interrupt abnormal electrical signals. It has a high cure rate for atrial flutter and is often recommended as a first-line treatment option for typical atrial flutter.
A variety of conditions can predispose a person to developing atrial flutter. Causes of atrial flutter include:
The most common complications of atrial flutter are heart failure and stroke. Atrial flutter can cause the heart to beat too rapidly. If the heart rate is uncontrolled over a prolonged period of time it can cause heart failure (tachycardia-mediated cardiomyopathy). Your pulse is determined by how many times the bottom chambers of your heart (ventricles) beats per minute. In atrial flutter, the atrial rate is often 2 times as fast as the ventricular rate. This means that if your pulse in atrial flutter is 150 bpm your atria are actually beating 300 times per minute. This very rapid atrial rate increases the risk of blood pooling in the sac-like structure which protrudes off the left upper heart chamber (left atrial appendage). The pooled blood is more likely to form a clot which can break off and cause a stroke.
Some people with atrial flutter do not have any symptoms. However, many people have significant symptoms which interfere with their ability to do the activities they enjoy and this affects quality of life. Adequate treatment of atrial flutter is therefore important not just to reduce risk of stroke, heart failure, or other complications but also to improve daily quality of life.
There are 4 treatment goals for atrial flutter:
Medications, electrical cardioversion or ablation can all be used to restore sinus rhythm. Atrial flutter catheter ablation is safe, well-tolerated, and has a very high cure rate. Radiofrequency ablation is especially effective for typical atrial flutter. Because of the high cure rate, ablation is usually preferred over antiarrhythmic medications, which can have a number of undesirable side effects.
C: Congestive heart failure – 1 point
H: High blood pressure (hypertension) – 1 point
A: Age greater than 75 years – 2 points
D: Diabetes mellitus – 1 point
S: History of stroke, transient ischemic attack or blood clots – 2 points
V: Vascular disease (i.e. heart attack, peripheral or coronary artery disease) – 1 point
A: Age 65-74 years – 1 point
Sc: Female – 1 point
Anticoagulation is recommended for men with a score of 2 or greater and for women with a score of 3 or greater. Because of the high cure rate of atrial flutter ablation, anticoagulation can generally be discontinued 4 weeks after atrial flutter ablation if there has been no recurrence of arrhythmia. However, if a person also has a history of atrial fibrillation, anticoagulation should be continued regardless of atrial flutter ablation success.
Atrial flutter usually results in a regular heart rhythm. Atrial flutter occurs when the atria beat too rapidly, which overrides the heart’s natural pacemaker (the sinus node). Luckily, the heart has a backup pacemaker called the AV node. The AV node acts as a gatekeeper between the upper chambers (atria) and lower chambers (ventricles) of the heart. In atrial flutter, the AV node filters out some of the frequent atrial impulses it receives. It is common for the AV node to only allow every other atrial beat to conduct to the ventricles. In this example, atrial flutter will occur in a pattern of 2 atrial beats for every 1 ventricular beat (2:1). Sometimes the AV node allows fewer atrial impulses through and atrial flutter may occur in other patterns such as 3 atrial beats to 1 ventricular beat (3:1) or 4 atrial beats to 1 ventricular beat (4:1). The AV node is usually quite regular in its filtering of the atrial beats it allows to conduct to the ventricles. This is why atrial flutter typically results in a regular heart rhythm and why a person who is in atrial flutter often reports a regular pulse.
The most dangerous form of atrial flutter is when the AV node allows every atrial impulse to conduct to the ventricles and there is 1 ventricular beat for every 1 atrial beat (1:1). The typical atrial rate in atrial flutter is 240 to 300 beats per minute. Therefore, if a person develops 1:1 atrial flutter the heart rate would be 240 to 300 beats per minute. This is not a sustainable heart rate and can lead to other, more dangerous abnormal heart rhythms. 1:1 atrial flutter has been noted to occur rarely amongst people taking certain antiarrhythmic medications, such as flecainide or propafenone. Fortunately this is very uncommon and is usually prevented by also prescribing a rate controlling medication like beta-blocker or calcium channel blocker.
Sometimes atrial flutter can go away on its own. However, even when it does go away spontaneously there is a high risk of recurrence. Therefore, your doctor may recommend certain treatments which may include medications and/or procedures. One of the most important parts of an effective atrial flutter treatment plan is to treat any underlying risk factors which are contributing to the arrhythmia. Most risk factors for atrial fibrillation or atrial flutter are what we call modifiable risk factors. The notable exceptions are age, gender and genetics.
Modifiable risk factors
Atrial fibrillation and atrial flutter can occur in athletes. In fact some studies have shown an increased incidence of atrial fibrillation amongst high intensity, competitive endurance athletes. In general however, athletes have improved cardiovascular fitness and less obesity, high blood pressure, diabetes, and sleep apnea. All of these have a positive effect on decreasing an athlete’s risk of developing atrial fibrillation and atrial flutter.