History
The setting and associated features of atrial flutter are an important aspect of the assessment of atrial flutter. This information may guide the design of a treatment plan, particularly in patients with repaired congenital heart disease.
Atrial flutter may be perceived as a regular or irregular palpitation, the latter suggesting variable atrioventricular (AV) conduction. The flutter may be associated with syncope, severe presyncope, or chest pain, suggesting either periods of 1:1 conduction ratio or associated ventricular dysfunction. Characterizing a history of previous self-terminating episodes is important. Rare and minimally symptomatic self-terminating episodes of atrial flutter are likely to require less treatment.
The presence of associated sinus node disease with episodes of sinus bradycardia may provide an indication for pacemaker therapy. This finding also adds to the antiarrhythmic medical options for atrial flutter.
Repaired congenital heart disease
Understanding the specific anatomy and surgical repair for each patient is important. Certain types of repair are more commonly associated with late atrial flutter than others.
In Fontan-type operations, atriopulmonary connections are associated with a risk of atrial flutter that is 2.5-fold higher than with the total cavopulmonary connection. Extracardiac Fontan repairs may have an even lower frequency of atrial flutter.
The type of repair may influence the technical approach to electrophysiological study, pacemaker placement, potential radiofrequency ablation therapy, or potential Fontan surgical revision. For example, patients who have the classic Fontan operation are amenable to ablation attempts of the atrial flutter in the electrophysiology laboratory because the right atrium can be approached via the inferior and/or superior vena cava. In addition, endocardial pacemaker leads can be inserted if the patient has sinus node dysfunction.
However, patients who have an extracardiac Fontan repair in which the right atrium has been bypassed with a baffle require open-heart surgery if ablation is contemplated, which is performed at the time of their Fontan revision. In addition, only epicardial pacemaker leads can be placed in these patients.
Atrial flutter also has prognostic significance in this setting. Several studies have shown that atrial flutter in the early postoperative period in patients who have undergone the Fontan operation predicts both early operative mortality and recurrence of the arrhythmia.
In patients with congenital heart disease who have undergone surgery, episodes of atrial flutter have been shown to increase in frequency over time.
Physical Examination
Physical examination in patients with atrial flutter should assess the likely conduction ratio and rate of flutter and assess for signs of associated ventricular dysfunction or heart failure. Depending on the ventricular rate and the individual's tolerance to that rate, symptoms may range from palpitations, dyspnea, presyncope, or syncope to sudden death. If the ventricular response is rapid, atrial flutter may cause significant morbidity secondary to hemodynamic deterioration due to low cardiac output.
If the ventricular response is slow enough to permit a sustained arrhythmia, atrial thrombosis with consequent thromboembolism may result. In patients who have undergone surgery for congenital heart disease, new onset of atrial arrhythmias such as atrial flutter may indicate elevated right atrial pressure and, thus, the need for surgery (eg, conduit obstruction in a patient with a Rastelli-type surgery).
In patients who have undergone the Fontan, Mustard, or Senning operation, the presence of superficial venous collateralization suggests associated obstruction of major venous pathways. This may interfere with evaluation and management.
Complications
Episodes of atrial flutter may be associated with low cardiac output, brain and other end-organ injury, and sudden or subacute death.
Heart failure, thrombosis, and thromboembolism are other recognized complications.
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Rhythm strip depicting lead II of a patient with atrial flutter with an atrial rate of 300 beats per minute (bpm). Atrioventricular conduction rate is variable at 2:1 and 3:1. Therefore, the ventricular rate ranges from 100-150 bpm.
