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

Choi, Kee Joon; Han, Kyoo Rok; Zo, Joo Hee; Kim, Hyo Soo; Kim, Cheol Ho; Sohn, Dae Won; Oh, Byung Hee; Lee, Myoung Mook; Park, Young Bae; Choi, Yun Shik; Seo, Jung Don; Lee, Young Woo

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, p<0.01), VApace-VAsvt(135.3+/-15.7 vs 55.0+/-33.5msec,p<0.01), and VAsvt/VApace(0.15+/-0.10 vs 0.75+/-0.14,p<0.05) were useful. Cutoff values were 95msec in VAsvt, 110msec in VApace-VAsvt and 0.5 in VAsvt/VApace. 2) There were no overlaps in VA intervals between the AV nodal reentry group and the AV reentry group with posteroseptal accessory pathway.3) In AV reentry tachycardia, VApace-VAsvt>50msec(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.