ABSTRACT
Noninvasive techniques for the localization of the accessory pathways [APs] might help guide mapping procedures and ablation techniques. We sought to examine the diagnostic accuracy of strain imaging for the localization of the APs in Wolff-Parkinson-White syndrome. We prospectively studied 25 patients [mean age = 32 +/- 17 years, 58.3% men] with evidence of pre-excitation on electrocardiography [ECG]. Electromechanical interval was defined as the time difference between the onset of delta wave and the onset of regional myocardial contraction. Time differences between the onset of delta wave [delta] and the onset of regional myocardial contraction [delta-So], peak systolic motion [delta-Sm], regional strain [delta-epsilon], peak strain [delta-epsilonp], and peak strain rate [delta-SRp] were measured. There was a significant difference between time to onset of delta wave to onset of peak systolic motion [mean +/- SD] in the AP location [A] and normal segments [B] versus that in the normal volunteers [C] [A: [57.08 +/- 23.88 msec] vs. B: [75.20 +/- 14.75] vs. C: [72.9 0 +/- 11.16]; p value [A vs. B] = 0.004 and p value [A vs. C] = 0.18] and [A: [49.17 +/- 35.79] vs. B: [67.60 +/- 14.51] vs. C: [67.40 +/- 6.06 msec]; p value [A vs. B] < 0.001 and p value [A vs. C] = 0.12, respectively]. Our study showed that strain imaging parameters [[delta-So] and [delta-Strain]] are superior to the ECG in the localization of the APs [84% vs. 76%]