Neonatal Atrial Flutter: A Novel Triad for Immediate Electrocardiographic Diagnosis

Neonatal atrial flutter (NAF) is a rare type of macroreentrant supraventricular tachycardia. In this report, we describe a case of atrial flutter in an 8-day-old neonate with a total anomalous pulmonary venous connection. Additionally, we introduce a diagnostic triad for electrocardiographic identification of this condition. This triad comprises three components: the Similar Shapes of Inter-QRS segments (SIS) in leads II, III, and aVF, Different Shapes of Inter-QRS Segments (DIS) in lead I, and the occurrence of one or multiple stretched M or inverted V shapes in the inter-QRS (IQS) segment in leads II, III, and aVF. We assessed the effectiveness of this triad through a validation cohort, using previously reported cases of neonatal atrial flutter from the literature. The sensitivity rates for detecting SIS and DIS patterns and the singular or multiple reversed W or V signs were 100%, 81%, and 100%, respectively. Furthermore, all three components of the triad were found in 81% of neonates diagnosed with atrial flutter. The emergence of this triad can be attributed to the elimination of the isoelectric segment in electrocardiography, caused by the extended duration of flutter waves originating from macro reentry within the atrium and the rapid atrial rate characteristic of atrial flutter.