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CHARACTERIZATION OF DIFFERENT LV ACTIVATION PATTERNS
BETWEEN HEART FAILURE PATIENTS WITH NARROW QRS,
NONSPECIFIC INTRAVENTRICULAR CONDUCTION DISTURBANCE
AND LEFT BUNDLE BRANCH BLOCK
Nicolas Derval, MD , Yuki Komatsu, MD, Frederic Sacher, MD, Sylvain Ploux, MD, Arnaud Denis,
MD, Hubert Cochet, MD, PhD, laurence jesel, MD, Han Lim, MBBS, Benjamin Berte, MD, saagar
mahida, MD, seigo yamashita, MD, Sana Amraoui, MD, Adlane Zemmoura, MD, Philippe Ritter, MD,
Meleze Hocini, MD, Michel Haissaguerre, PhD, Pierre Jais, MD and Pierre Bordachar, MD. CHU de
BORDEAUX, Hopital Cardiologique Haut Leveque, Institut LYRIC, Bordeaux France.
Background: There is a lack of precise and detailed invasive mapping investigation in heart failure
patients with narrow QRS or nonspecific intraventricular conduction disturbance (NICD). We aimed to
characterize the LV activation pattern in patients with heart failure and different ventricular conduction
disturbance to better understand the electrophysiological background for LV dysfunction and effect of
CRT.
Methods: LV activation sequence was studied in 49 heart failure patients (EF=30+/-7%) with narrow
QRS (n=16), left bundle branch block LBBB (n=11) and NICD (n=22) referred for catheter ablation of
ventricular tachycardia using 3D navigation system (Carto 3 - Biosense Webster or Ensite - SJM).
Results: During the mapping procedure an average of 261+/-200 equally distributed LV contact points
were acquired. The pattern of activation had important similarities in patients with LBBB: 1. Single LV
breakthrough in the septum recorded 45±16 ms after the beginning of the QRS complex traducing a
prolonged right-to-left transseptal activation time and absence of direct LV Purkinje activation; 2. Slow
homogeneous cell-to-cell propagation inside LV cavity; 3. Basal lateral wall as the latest activated
region.
The pattern of activation had both important similarities and differences in patients with NICD and
narrow QRS: 1. Multiple LV breakthrough along posterior and/or anterior fascicles: 4±2 in narrow QRS
(p=0,0004 vs LBBB), 4±2 in NICD (p<0,001 vs LBBB; p=ns vs narrow QRS); in these 2 groups,
recording of early/preQRS LV EGMs with Purkinje potentials; 2. Fast propagation in patients with
narrow QRS, more heterogeneous propagation in patients with NICD. 3. Presence of limited areas of
late activation in both narrow QRS and NICD patients with high interindividual heterogeneity in terms
of late activated areas.
Conclusion: We observed high homogeneity in the electrical activation of patients with LBBB in favor
of a positive predictable response to CRT. In contrast, patients with narrow QRS and NICD
demonstrated more heterogeneity and factors in favor of poor response: multiple LV breakthroughs,
preserved Purkinje activation and localized limited areas of delayed activation.