# A Study of the Frequency of Lead Reversal at a Tertiary Care Institution

## TL;DR

This study finds that lead reversal in ECG recordings occurs in 1.5% of cases at a tertiary hospital, emphasizing the need for proper training to avoid misdiagnosis.

## Contribution

The study quantifies the frequency of ECG lead reversal in a clinical setting and identifies common patterns of misplacement.

## Key findings

- Lead misplacement occurred in 1.5% of 1,000 ECGs reviewed.
- Limb lead reversal was most common, with LA-LL reversal at 0.8% and RA-LA reversal at 0.3%.
- Chest lead reversal was observed in 0.4% of cases.

## Abstract

Background: Electrocardiography (ECG) remains an important point-of-care investigative modality in the screening and diagnosis of cardiac diseases due to rapidity, cost-efficiency, and a gentle learning curve for most emergent patterns. Mechanistical problems in recording ECGs can lead to distorted graphical representations of cardiac electrophysiology, which can lead to incorrect or obstructed care for the patient.

Aim: To identify the prevalence of ECG lead reversal in a tertiary care hospital over two months and to discuss the various patterns of ECG lead misplacement.

Methods: A total of 1,000 ECGs were screened over a period of two months. ECGs with features suspicious for lead misplacement were identified, the corresponding patients had a repeat ECG taken under supervision, and the presence or absence of lead misplacement was verified on the basis of chest lead progression, inverted limb complexes, and isolated flatlines. ECGs of paediatric patients (<18 years) and patients with cardiac axis abnormalities (e.g., dextrocardia) were excluded.

Results: Fifteen out of 1,000 ECGs were confirmed to have lead misplacement (1.5%). Eleven (1.1%) of these had limb lead reversal, of which eight were LA-LL reversal (0.8%) and three were RA-LA reversal (0.3%). Four ECGs had evidence of chest lead reversal (0.4%).

Conclusion: It is important for healthcare professionals to learn to recognize electrical patterns of lead reversal, as the ECG must be retaken promptly and carefully after repositioning the leads correctly, in order to avoid delays or disturbances in the care of patients.