An interesting electrocardiogram caused by lead reversal

Abstract

Abstract Background During normal sinus rhythm, atrial depolarization is conducted from right atrium to left atrium through Bachmann’s bundle, and a normal P wave axis which is measured on the frontal plane is between 0º and + 75º. The change of P wave polarity is helpful for the analysis of origin point. Case presentation We report a patient with negative P wave in lead I. The characteristics of QRS complex in leads V1 to V6 are helpful to preliminarily differential diagnosis. The 12-lead electrocardiogram (ECG) with correct limb leads (right arm-left arm) placement shows sinus rhythm with complete right bundle branch block (RBBB). Conclusions The change of P wave polarity as well as characteristics of QRS complex can help identify limb-lead reversals.

Keywords

• Limb-lead reversals
• Electrocardiogram
• Mirror-image dextrocardia
• Acquired dextrocardia
• Left atrial rhythm