Novel surface ECG criteria for differentiation between left- and right-sided manifest inferoseptal accessory pathways

Area of Science:

• Electrophysiology
• Cardiology
• Medical Diagnostics

Background:

• Inferoseptal accessory pathways can be difficult to differentiate between left- and right-sided locations using current electrocardiogram (ECG) algorithms.
• Accurate localization is crucial for successful radiofrequency ablation procedures.

Purpose of the Study:

• To evaluate the effectiveness of existing ECG criteria for differentiating left- and right-sided inferoseptal accessory pathways.
• To identify novel ECG criteria for improved localization of these pathways.

Main Methods:

• Retrospective review of 12-lead ECGs from 113 patients with successful ablation of a single manifest inferoseptal accessory pathway.
• Analysis of QRS polarity in inferior leads (II, III, aVF) and precordial lead V1 to predict pathway location (mitral or tricuspid annulus).
• Calculation of positive predictive value (PPV) and negative predictive value (NPV) for identified ECG criteria.

Main Results:

• A negative QRS polarity in all three inferior leads and V1 showed a high PPV (0.90) for right-sided pathways.
• A negative QRS polarity in at least two inferior leads and V1 also indicated a right-sided location (PPV 0.80).
• A positive QRS polarity in at least one inferior lead predicted a left-sided pathway location (PPV 0.54).
• A newly developed algorithm achieved an overall accuracy of 76% in differentiating pathway locations.

Conclusions:

• Existing ECG algorithms are unsatisfactory for differentiating left- and right-sided inferoseptal accessory pathways.
• Specific QRS polarity patterns in inferior leads and V1 can reliably predict pathway location.
• The developed algorithm offers improved accuracy for localizing inferoseptal accessory pathways, aiding ablation strategies.