A new approach to confirming or excluding ventricular pre-excitation on a 12-lead ECG.

AIMS

The purpose of this study was to determine simple features of the standard 12-lead electrocardiogram (ECG) and incorporate them in a stepwise algorithm that would help confirm or exclude the presence of ventricular pre-excitation.

METHODS AND RESULTS

We retrospectively analysed multiple variables on pre- and post-ablation ECGs in 238 patients with manifest accessory pathways that had been successfully ablated. A new variable, PR dispersion, was defined as a difference between maximum and minimum PR intervals on a single 12-lead ECG. A logistic regression analysis showed the combination of the following criteria to be powerful in the confirmation of the diagnosis in patients with suspected delta wave: presence of both PR interval < or = 120 ms and PR dispersion > or = 20 ms, absence of initial positive deflection (septal R wave) in lead augmented voltage right arm (aVR), and horizontal QRS transition in lead V1 or before. A stepwise algorithm was developed based on these criteria. Of the total 476 ECGs, seven patients with pre-excitation and one patient with normal ECG were misdiagnosed using the algorithm. Even though the retrospectively determined sensitivity and specificity of the three stepwise criteria were high (97% and 99%, respectively) a prospective study evaluating the algorithm is needed.

CONCLUSION

Using a stepwise approach is a very sensitive and specific technique for excluding or confirming ventricular pre-excitation on a 12-lead ECG.