The Value of Ventriculoatrial Intervals in Determining the Mechanism of PSVT and the Sites of Accessory Pathways

ABSTRACT

The ventriculoatrial(VA) intervals during supraventricular tachycardia(VAsvt) and during pacing with same cycle length as tachycardia(VApace) were analysed in 48 patients to evaluate the usefullness in determining the mechanism of paroxysmal supraventricular tachycardia(PSVT) and the sites of accessory pathways. The results are as follows 1)In differenciation AV nodal reentry from AV reentry mechanism, VAsvt(25.6+/-21.5 vs 148.0+/-27.7msec, p50msec(sensitivity 81%,specificity 100%) and VAsvt/VAace<0.7(sensitivity 71%, specificity 100%) suggested the high probability of left free wall accessory pathway. In Conclusion, VAsvt, VApace-VAsvt and VAsvt/VApace are useful parameters in determining the mechanism of PSVT and the sites of accessory pathways.