Neonatal atrial flutter is a rare arrhythmia of the newborn. Often the fast heart rate in the fetus is considered a sign of fetal distress. In this ECG the ventricular rate is over 200 per minute. The ‘saw tooth’ shaped flutter waves are seen well in the lead II rhythm strip. The negative flutter waves suggest typical atrial flutter with counter-clockwise re-entry loop. There is one QRS complex for every two flutter waves. Hence the conduction ratio is 2:1, indicating atrial rate over 400 per minute. Dominant R wave in V1, right axis deviation and clockwise rotation in the frontal plane QRS pattern are suggestive of neonatal ECG pattern. The atrial and ventricular rates are faster than the usual flutter rates in the adult, which is typically and atrial rate of 300 per minute and ventricular rate of 150 per minute in case of 2:1 conduction.
In a series of 50 infants reported by Texter TM et al, almost three fourth presented within first two days of life and one fifth had features of congestive heart failure. Spontaneous conversion to sinus rhythm occurred in about one fourth of them. Of the 23 in whom cardioversion was attempted, 20 could be successfully cardioverted. Reversion by transesophageal pacing was attempted in 22, but only 7 were successful. 7 infants required anti arrhythmic medications.