From the Guidelines
The differential diagnosis for lead reversal includes limb lead misplacement, precordial lead misplacement, and mirror-image dextrocardia.
Key Considerations
- Limb lead misplacement can result in inversion of limb lead I, switch of leads II and III, and switch of leads aVR and aVL, whereas aVF remains unaltered 1.
- Precordial lead misplacement, such as transposition of lead wires to V1 and V2, can cause a reversal of R-wave progression that simulates anteroseptal wall infarction 1.
- Mirror-image dextrocardia can be distinguished from lead misplacement by the discordance between lead I and V 1.
Diagnostic Approach
- Suspected lead switches can be confirmed by reference to a prior or subsequent tracing with correct lead placement 1.
- Computerized electrocardiography can aid in the standardization of measurements and improve the separation of normal from abnormal ECGs 1.
- Technical factors, such as operator selection of inadequate bandwidth and misplacement of limb or precordial electrodes, can limit the reliability of measurements and introduce artifactual deviations 1.
From the Research
Differential Diagnosis for Lead Reversal
The differential diagnosis for lead reversal in an electrocardiogram (ECG) includes various conditions that can mimic or be mimicked by lead reversal errors. Some of these conditions include:
- Inferior wall myocardial infarction (IWMI) 2, 3
- High lateral wall myocardial infarction (LWMI) 3
- Nonsinus atrial rhythm 2
- Benign early repolarization or J-point elevation 4
- STEMI mimic 4
Lead Reversal Errors
Lead reversal errors can occur due to various reasons, including:
- Improper placement of recording electrodes on the skin 2
- Inadvertent interchange in the lead cables at the point where they insert into the cable junction box of the ECG machine 5
- Exchanging the right arm and left leg leads, which can create what seems to be an inferior wall myocardial infarction and a nonsinus atrial rhythm in normal patients 2
- Reversal of the right arm and right leg connections, which can create a unique pattern of diffuse low voltage in the limb leads 2
- Precordial lead switches, which can be recognized by the abnormal R wave progression that is created 2
Detection and Reconstruction of Lead Reversal
Detection and reconstruction of lead reversal can be done using various methods, including:
- Simulating arbitrary electrode reversals in standard 12-lead ECG 6
- Using algebraic transformation for simulation of all possible ECG cable reversals, including those with displaced Wilson's central terminal (WCT) potential 6
- Applying 'Forward' and 'Inverse' transformations to detect and reconstruct lead reversals 6
- Using the REVERSE mnemonic to identify possible lead reversal 4