Reappraisal of classical electrocardiographic criteria in detecting accessory pathways with a strict para-Hisian location

BackgroundIdentification of electrocardiographic (ECG) criteria for para-Hisian accessory pathways (APs) is based on a small series of patients. The presence of a negative delta wave in leads V1 and V2 has been suggested as an ECG marker of this AP location.ObjectiveTo validate these ECG findings in a large series of patients with strict invasive criteria for that location.MethodsWe included 105 patients (39 women, 66 men; mean age 26±12 years, range 5–82 years) with an ECG pattern compatible with preexcitation through an anteroseptal or midseptal AP following established ECG criteria. A para-Hisian AP was defined when the location of its successful catheter ablation coincided with either the largest recordable His bundle electrogram or a His bundle potential of>0.1 mV. Patients without that definition were included in the control group.ResultsA para-Hisian location of the AP was found in 52 patients. AP locations of the remaining 53 patients (control group) were anteroseptal (n = 39), midseptal (n = 9), and fasciculoventricular (n = 5). A negative delta wave in leads V1 and V2 was observed in 13 patients with para-Hisian APs (sensitivity 25%; specificity 92%). However, the sum of initial r-wave amplitudes in those leads was<0.5 mV in 44 of the patients with para-Hisian APs and in 13 patients of the control group (sensitivity 85%; specificity 75.5%; area under receiver-operator characteristic curve 0.85).ConclusionsThe presence of negative delta waves in leads V1 and V2 indicates a poor sensitivity and high specificity to detect APs with a strict definition of para-Hisian location. The sum of initial r-wave amplitudes in those ECG leads could be a useful, adjunctive marker in the noninvasive identification of these challenging APs.