Detection of electrocardiographically imperceptible ventricular pre‐excitation by phase imaging

Abstract

Summary:The sequence of vcntricular contraction was studied by radionuclide phase imaging in 25 patients with Wolff-Parkinson-White syndrome. The studies were perfomied when no signs of precontraction were present in the electr[)cardiogram; in these cascs pre-excitation was either intermittent o r suppressable by injection of ajmaline. In 1 1 of the 16 patients with free wall accessory pathways, precontraction could be detected in spite of electrocardioEraphicaIly absent pre-excitation. Discrete precontraction was seen also in 2 of the 9 patients with paraseptal accessory pathways. We conclude (1) that antegrade conduction through the accessory pathway does not need to bc completely blocked if signs of pre-excitation are absent on the electrocardiogram, and ( 2 ) that phase imaging is, at least in some patients (especially those with free wall accessory pathways), a more sensitive technique for detection of pre-excitation (precontraction) than the electrocardiogram.

Decreased amplitude of left ventricular posterior wall motion with notch movement to determine the left posterior septal accessory pathway in Wolff-Parkinson-White syndrome

“…Therefore these reports did not provide sufficient information for precise sublocation of the accessory pathway 12. Recently, more complicated methods, such as phase analysis of echocardiographic images13 14 and radionuclide ventriculography,15 have been employed to detect the accessory site. These methods have focused mainly on pre-excitation ventricular motion through the accessory pathway, but the diagnostic criteria are complicated and the accuracy of the methods is limited.…”