- Poster presentation
- Open Access
Assessment of intra- and inter-ventricular cardiac dyssynchrony in patients with repaired Tetralogy of Fallot: a cardiac magnetic resonance study
© Jing et al.; licensee BioMed Central Ltd. 2014
- Published: 16 January 2014
- Outflow Tract
- Right Bundle Branch Block
- Cardiac Magnetic Resonance Study
- Dyssynchrony Index
- Early Contraction
Patients with repaired tetralogy of Fallot (TOF) frequently have right bundle branch block. However, the contribution of cardiac dyssynchrony to dysfunction remains controversial. To better understand this phenomenon and ultimately study therapies, we developed a method to quantify left (LV), right (RV) and inter-ventricular cardiac dyssynchrony using standard cine CMR.
30 patients with repaired TOF (age 28 ± 16, 46% female) and 17 healthy controls (age 29 ± 7, 12% female) underwent cine CMR. Patients were imaged twice to assess inter-test reproducibility. Circumferential strain vs time curves were generated with a custom feature tracking algorithm for 12 LV and 12 RV segments in 4-7 slices encompassing the ventricles. For each segment, the temporal offset (TO) of the strain curve relative to a global reference curve derived from the controls was calculated and expressed as a percent of the cardiac cycle. The intra-ventricular dyssynchrony index (DI) for each ventricle was computed as the standard deviation (SD) of the TOs (more dyssynchrony increases the SD). The inter-ventricular DI was calculated as the difference in median RV and median LV TOs. Regional dyssynchrony was quantified in 3 LV (septum, infero-lateral and antero-lateral wall) and 3 RV (septum, sinus, outflow tract) regions using median TOs.
Patients with repaired TOF suffer from left, right and inter-ventricular cardiac dyssynchrony which can all be quantified from standard cine CMR with good inter-test reproducibility. Future studies need to determine whether these patients may benefit from resynchronization therapy.
This work was supported by a National Institutes of Health (NIH) Director's Early Independence Award (1DP5OD012132-01), and NIH grant number KL2 RR033171 from the National Center for Research Resources and the National Center for Advancing Translational Sciences. The content is solely the responsibility of the authors and does not necessarily represent the official views of NIH.
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