Atrial flutter
Definition
Atrial Flutter is a common abnormal heart rhythm that starts in the atrial chambers of the heart. It is characterized by a rapid but regular rhythm, which distinguishes it from the more chaotic rhythm of atrial fibrillation.
Epidemiology
Atrial flutter is less common than atrial fibrillation, but it is not rare. It is estimated to affect around 200,000 to 1 million individuals in the United States each year. The incidence increases with age, with the majority of cases occurring in individuals over 60 years of age.
Pathophysiology
Atrial flutter is caused by a re-entry circuit within the right atrium. The most common form is 'typical' atrial flutter (also known as 'type I' or 'cavotricuspid isthmus-dependent' atrial flutter), which involves a large re-entry circuit that travels up the right atrial septum, across the roof of the atrium, down the lateral wall, and then through the cavotricuspid isthmus.
Clinical Features
Symptoms of atrial flutter can vary significantly between individuals. Some people may be asymptomatic, while others may experience symptoms such as palpitations, fatigue, shortness of breath, or chest pain. In some cases, atrial flutter can lead to serious complications such as stroke or heart failure.
Diagnosis
The diagnosis of atrial flutter is typically made based on the clinical history and physical examination, supported by electrocardiogram (ECG) findings. The ECG in atrial flutter typically shows a 'sawtooth' pattern of regular atrial activity at a rate of 240-340 beats per minute.
Management
The management of atrial flutter involves three main strategies: rate control, rhythm control, and prevention of thromboembolic complications. Rate control is achieved with medications such as beta-blockers or calcium channel blockers. Rhythm control may be achieved with antiarrhythmic drugs or with a procedure called catheter ablation. Anticoagulation with drugs such as warfarin or direct oral anticoagulants is often necessary to prevent stroke.
Prognosis
The prognosis of atrial flutter is generally good, especially with appropriate treatment. However, it can be a cause of significant morbidity due to symptoms and the risk of complications.