ECG differential diagnosis of narrow QRS complex tachycardia in the emergency department: A review of common rhythms and distinguishing features

Borloz MP, Mark DG, Pines JM, Brady WJ

The differentiation of narrow complex tachycardias (NCT) is a commonly encountered

diagnostic dilemma in the adult emergency department. Some NCTs (e.g., sinus

tachycardia) are secondary to the presenting complaint (e.g., fever, anxiety, pain) and will

respond to appropriate treatment of the inciting pathologic insult. Alternatively, other

NCTs (e.g., atrial fibrillation, AV nodal reentrant tachycardia) may indeed be the cause of

the chief complaint (e.g., palpitations, lightheadedness from poor perfusion) and must be

positively identified and primarily managed. An appreciation of the similarities and

differences among these NCTs is necessary for appropriate recognition. This article

delineates which demographic, historical, and electrocardiographic characteristics are

helpful in identifying the following rhythms: sinus tachycardia, sinus node reentrant

tachycardia, unifocal atrial tachycardias, multifocal atrial tachycardia, atrial fibrillation,

atrial flutter, atrioventricular nodal reentrant tachycardia, and atrioventricular reentrant

tachycardia. In addition, a discussion of various diagnostic maneuvers, such as adenosine

administration, is included.

Borloz MP, Brady WJ, Mark DG, Pines JM