Correlation between areas of ventricular preexcitation and types of WPW QRS patterns by means of computer simulation of ventricular activation sequence.

Computer simulation of the ventricular activation sequence of the WPW syndrome was attempted by producing fusion beats in which localized ventricular myocardium was activated earlier than the "normal excitation". It suggested that the site of pre-excitation was; i) at the posterior or the lateral free wall of the left ventricle adjacent to the A-V groove in type A, ii) at the antero-lateral base of the right ventricle in type B, and iii) at the posterior paraseptal region of the right ventricle in type C. A mild degree of pre-excitation at the left ventricular postero-lateral region will result in type B QRS complexes.