Abstract 15765: Quantitative 3D Echocardiography in Children With Congenital Complete Heart Block: The Effect of Pacing and Lead Position on Ventricular Function and Synchrony
Background: Pacemakers in general and some lead positions in particular may adversely affect ventricular function (fxn) and synchrony (sync) in congenital complete heart block (CCHB). 3D echocardiography (3DE) can measure fxn & sync.
Aims: Compare fxn and sync in 1.normal vs CCHB. 2. LV apex epicardial (LVAE) vs RV apex transvenous (RVAT) pacing.
Methods: Retrospective review of medical records, standard echo and 3DE of 18 with CCHB vs. 20 normal controls. Fxn and sync were measured by M- mode, tissue Doppler (tdi) and 3DE. 3DE with Philips iE33 & 3DAQ software included 1. 3D LVEF; 2. 16SD% = standard deviation of the time to minimum systolic volume for 16 cardiac segments; 3. 16Diff% = maximum time difference between the first and last contracting segments. Both 2 & 3 are expressed as % of RR interval. Generalized linear model regression statistics were used.
Results: 1. CCHB vs normal:(table) CCHB has statistically slightly lower ventricular fxn vs. normals. The differences are small and CCHB fxn parameters remain within published norms. For sync parameters, CCHB tdi inter and intraventricular delays were statistically different vs normals, but remained within published norms. 16SD% and Diff16% were mildly abnormal in CCHB. 2. LVAE vs RVAT: (table) the LVAE group has slightly higher fxn and lower tdi interventricular delay. However, the LVAE were younger with shorter pacing duration.
Conclusions: Most with CCHB have preserved fxn and normal to mildly abnormal sync. Small but statistically significant differences in fxn and sync are present between various groups. These differences may not be of clinical significance. LVAE have statistically slightly higher fxn but similar sync parameters vs. RVAT. Different age and pacing duration confound reliable interpretation of LVAE vs RVAT results. These data do not strongly support changing the current strategy of early LVAE followed by later RVAT. Large groups and long term study are needed.
- © 2011 by American Heart Association, Inc.