The synthesized vectorcardiogram resembles the measured vectorcardiogram in patients with dyssynchronous heart failure

Background: The use of vectorcardiography (VCG) has regained interest, however, original Frank-VCG equipment is rare. This study compares the measured VCGs with those synthesized from the 12-lead electrocardiogram (ECG) in patients with heart failure and conduction abnormalities, who are candidate for cardiac resynchronization therapy (CRT). Methods: In 92 CRT candidates, Frank-VCG and 12-lead ECG were recorded before CRT implantation. The ECG was converted to a VCG using the Kors method (Kors-VCG) and the two methods were compared using correlation and Bland-Altman analyses. Results: Variables calculated from the Frank- and Kors-VCG showed correlation coefficients between 0.77 and 0.90. There was a significant but small underestimation by the Kors-VCG method, relative bias ranging from -1.9%+/- 4.6% (QRS-T angle) to -9.4%+/- 20.8% (T area). Conclusion: The present study shows that it is justified to use Kors-VCG calculations for VCG analysis, which enables retrospective VCG analysis of previously recorded ECGs in studies related to CRT.