ASSESSMENT OF CARDIAC RESYNCHRONIZATION THERAPY BY NON-INVASIVE RECONSTRUCTION OF CARDIAC ACTIVATION TIMES

摘要

The compuational reconstruction of cardiac activation times in a noninvasive manner was performed in ten pa tients with congestive heart failure (CHF), complete left bundle branch block (LBBB) patients undergoing cardiac resynchronization therapy (CRT) and ten patients with out structural heart disease undergoing an EP study (con trol group). The noninvasive funtional imaging technique employed in this study fused data from high-resolution ECG mapping with a model of the patient's individual car diac and thoracic anatomy obtained by magnetic resonance imaging. Single beat endo- and epicardial ventricular acti vation sequences were computed during native rhythm and ventricular pacing. A bidomain theory based algorithm was employed solving the underlying ill-posed inverse problem of electrocardiography. The control group showed a dete rioration of the ventricular activation sequence during right ventricular pacing, which was found to be similar to the in trinsic activation pattern of CHF patients. CHF patients had a right-to-left septal activation with the latest activation in the epicardial lateral wall of the left ventricle. Biventricular pacing led to a resynchronization of biventricular activation sequences and to a significant decrease of the total left ven tricular activation duration compared to intrinsic conduc tion and RV pacing (129 ± 16 versus 157 ± 28 and 173 ± 25 ms; both p < 0.05). Endocardial and epicardial ven tricular activation of structurally healthy individuals and of patients with CHF or LBBB can be visualized in a nonin vasive manner by the method proposed in this study. Thus noninvasive determination of individual patients' ventricu lar activation properties might help to further improve pos itive responses to CRT by pacemaker therapy tailored to a patient's specific needs.