Atrial flutter is a relatively common heart rhythm disturbance encountered by doctors, although not as common as atrial fibrillation (AF). The precise incidence of atrial flutter is not known, but it affects around 1 in 1,000 people in the UK. It can affect adults of any age, but is more common in older patients and is also seen more often in men.
Atrial flutter has many clinical aspects that are similar to AF and the two arrhythmias often occur in the same patient. However, there are important diff erences with respect to the electrical origins of these rhythm disturbances, and this can have a bearing on the treatment.
What is atrial flutter?
Atrial flutter is an abnormality in the rhythm of the heart (arrhythmia). In this arrhythmia, the upper chambers of the heart (atria) beat very rapidly. Unlike atrial fibrillation (AF), atrial flutter is a more organised electrical disturbance which originates in the right atrium in the majority of patients. The atria in atrial flutter beat very quickly and regularly, at around 300 beats per minute, and hence take over from the sinus node in controlling the heart rate. The AV node will not conduct all of these atrial beats to the ventricles but tends, instead, to only allow every second, third or fourth beat through, creating an often-regular heart rate of around 150, 100 or 75 beats per minute. Other ratios can occur, and often the ratio changes.
This increased heart rate may contribute to symptoms of palpitations, shortness of breath, chest discomfort, light headedness or fatigue when atrial flutter occurs. As with AF, there are two main goals in the treatment of atrial flutter. First is the control of the rhythm itself, either by restoring normal heart rhythm or normal heart rate and hence reducing the majority of the symptoms caused by the arrhythmia. Second is to prevent complications of atrial flutter, which are mainly due to an increased risk of stroke.
What causes atrial flutter?
As atrial flutter and AF share many similarities and can occur in the same patient, the two arrhythmias share many causes. atrial flutter is more likely to occur as one gets older, and is more common in patients who have a history of previous heart disease. Men are more than twice as likely to get atrial flutter as women. Often there is no single factor that causes atrial flutter; rather there are a number of factors and conditions that increase the likelihood of atrial flutter.
Some of the risk factors for developing atrial flutter are shown below:
- High blood pressure Congenital heart disease (abnormality of the heart present since birth)
- Ischaemic heart disease Pericarditis (inflammation of the heart lining)
- Disease of the heart valves
- Over active thyroid
- Cardiomyopathy Chronic airways disease (COPD)
- Excess alcohol
- Cardiac surgery
- Pulmonary embolism (clot on the lung)
However these are not the only causes for developing atrial flutter and for some here may appear to be no obvious reason.
What are the symptoms of atrial flutter?
Some people with atrial flutter experience no symptoms and the arrhythmia can be a chance fi nding on a routine ECG. Common symptoms are:
• Palpitations (awareness of rapid or irregular heart rate)
• Fatigue or poor exercise tolerance
• Mild shortness of breath
• Less common symptoms include chest pain and fainting
Treatment of atrial flutter
The treatment of atrial flutter follows similar lines to the treatment of AF. Treatment is centred round reducing symptoms and reducing risk of stroke, so
the treatment for individuals may vary depending upon their symptoms and their stroke risk.