Body surface Laplacian maps for patients with left or right ventricular bundle branch block

The objective of this study was to test the clinical utility of body surface Laplacian maps (BSLMs). BSLMs were studied during ventricular depolarization for complete right or left ventricular bundle branch block (CRBBB or CLBBB). Ten patients in each group were studied. 128 electrodes were placed on the entire torso. BSLMs were computed using an algorithm developed in our laboratory. BSLMs showed multiple and more localized positive and negative activities compared with body surface potential maps (BSPMs). In the patients with CRBBB, BSLMs showed more localized left ventricle (LV) apex breakthrough, LV anterolateral breakthrough, separated LV lateral and posterior wall activation. In the patients with CLBBB, BSLMs showed multiple right ventricle (RV), LV anterior wall activation, and propagating activation from LV lateral to posterior wall. The present results indicate that BSLMs provide enhanced capability in detecting multiple ventricular electrical events associated with conduction abnormalities and more detailed activation sequences of both ventricles revealed in the patients with CRBBB and CLBBB. The BSLM may provide an important alternative to other imaging modalities in localizing cardiac electrical activity non-invasively.