Atrial flutter is another narrow complex tachyarrhythmia that is rare but can occur in infants and children with normal hearts. More commonly, atrial flutter may be associated with congenital heart disease or cardiac surgery.
Atrial flutter occurs because of a reentry circuit within the atria that allows the depolarization cycle to travel in a circle within the atria. This causes the atria to rapidly depolarize over and over independently of the ventricles.
Atrial rates can independently exceed 300/min. This rapid depolarization of the atria creates the classical sawtooth presentation of the P-waves on an ECG.
Since the AV node is not part of this reentry circuit, the ventricular conduction and depolarization may be variable, and the ventricular rate can be regular or irregular.
Once SVT is recognized, it should be managed with one of the tachycardia algorithms.
For the management of SVT use these three questions to determine which tachycardia algorithm to use. These questions will also direct the management within the algorithm:
1. Is a pulse present?
2. Is perfusion adequate?
3. Is the QRS complex normal/narrow or wide (narrow complex QRS (≤ 0.09 sec) or wide complex QRS (>0.09)?
(Note about atrial fibrillation:
Atrial fibrillation is extremely rare among infants and children. If atrial fibrillation is present, expert consultation is indicated.)
If there is a drop in cardiac output, an infant or child may experience the following signs and symptoms.
Shortness of air
Palpitation feeling in chest
Ongoing chest pain
Altered or complete loss of consciousness
Capillary refill > 2 sec.
Other signs of shock
Characteristics of the ECG for atrial flutter include:
Heart Rate: Ventricular rate will vary from the atrial rate. Atrial rates may exceed 300/min. Ventricular rate may be irregular.
P waves: Classical sawtooth pattern
R to R interval: may be variable
QRS complex: Usually narrow. May be wide of an aberrancy is present, but this is rare.
Perfusion status is the decision point for determining which tachycardia algorithm is used.
Note: Procainamide is effective for the treatment of atrial flutter and atrial fibrillation. (Seek expert consultation when using procanamide.)
Definitive treatment for infants and children with unstable (poor perfusion) atrial flutter is synchronized cardioversion.
If the infant or child is stable (good perfusion) expert consultation should be obtained prior to treatment.