A New Electrocardiographic Criterium to Estimate a Septal or Lateral Location of a Right-Sided Accessory Pathway

Abstract

There are algorithms to estimate the location of an accessory pathway (AP), but they tend to present low accuracy in right-sided APs. This paper presents a new electrocardiographic criterium to estimate the location of a right-sided AP. Rest ECGs from patients with manifest preexcitation of right-sided APs were evaluated and the SV2/RV3 ratio was calculated, considering values < 1 for lateral (anterior or posterior) and ≥ 1 for septal (anterior or posterior) APs. This ratio was compared with other signs already described in literature. In 175 consecutive patients, 60 met the inclusion criteria. For APs located in superior portions of the tricuspid ring, the SV2/RV3 ratio < 1 was 80% accurate for anteroseptal location (specificity: 75%), where His electrograms were recorded. For APs located in inferior portions of the tricuspid ring a SV2/RV3 < 1 was 82,86% accurate for mid and posteroseptal location (specificity: 95.38%). This work reports a new and simple criterium that can accurately distinguish right-sided lateral and septal APs with good specificity: SV2/RV3 ratio.

Keywords

• ardiac arrhythmia
• electrocardiography
• accessory atrioventricular pathway.