Spatial Ventricular Gradient in Patients withWolff-Parkinson-White Syndrome in Comparison withNormal Subjects. Vectorcardiographic Evidence forSignificant Repolarization Changes due to Preexcitation.

Abstract

We investigated the use of the spatial ventricular gradient (VG) from vectorcardiogram (VCG) to determine whether significant repolarization differences were present in patients with WPW syndrome compared with normal subjects and also examined which VGparameter (i.e., elevation, azimuth, and magnitude) reflected the differences in repolarization properties during preexcitation. VG was calculated in 49 patients ofWolff-Parkinson-White (WPW) syndrome (group A: left-sided accessory pathway, n=29; group B: right-sided, n=20). Group N consisted of 607 normal subjects. In group A, the azimuth ofVG was significantly (p<0.01) greater than in groups B and N. In group B, the elevation of VGwas significantly (p<0.01) greater than in groups A and N. There were no significant differences in the magnitude of VGamonggroups. QRSduration was significantly (p<0.01) related with the elevation ofVG in group B. These findings suggested that VGis useful for spatial evaluation of repolarization abnormalities during preexcitation, which are related to the site of the accessory pathway. (Internal Medicine 34: 738-743, 1995)

Comparison of Vectorcardiographic and 12-lead Electrocardiographic Detections of Abnormalities in Repolarization Properties due to Preexcitation in Patients with Wolff-Parkinson-White Syndrome.

“…We have previously reported repolarization abnormalities in patients with manifest WPW syndrome using QRST isointegral mapping (87-lead body surface QRST time integral values), 25,26) QRST time integral values in 12-lead ECG, 27) activation-recovery interval obtained from body surface mapping, 23) and spatial VG from VCG. 18) Sawada, et al 18) reported that VG were directed more anteriorly in patients with manifest left-sided accessory pathways and more superiorly in patients with manifest rightsided accessory pathways compared with normal subjects. In the present study, although we found that abnormalities in direction of VG before ablation did not normalize significantly 1 day after ablation in patients with manifest WPW syndrome, they showed significant changes toward the normal mean 1 week after ablation.…”

“…Electrophysiologic study and radiofrequency catheter ablation: Antiarrhythmic drugs were discontinued for at least 5 elimination half-lives before the preablation maps were recorded. Multiple 6F multipolar electrode catheters were introduced percutaneously into the femoral and subclavian veins for 18,21) so we will describe them only briefly. Frank X, Y, and Z ECGs and unipolar ECGs with Wilson's central terminal used as a reference were recorded simultaneously.…”

“…The spatial vectorcardiogram (VCG) is of great value in three-dimensional analysis of repolarization abnormalities in various settings including abnormal activation sequences. 6,7,[17][18][19][20] Recently, Shvilkin, et al 7) utilized VCG to investigate long-term cardiac memory in canine experiments. They also demonstrated that a change in the pathway of activation induced long-term cardiac memory resulting from new protein synthesis and changes the action potential duration in ventricular myocytes.…”