Abstract 15229: Quantitative Analysis of Global Left Ventricular Contraction Dyssynchrony by 256 Slice CT
Aim: The aim of this study was to assess whether CT could be feasible to detect the cardiac conduction dyssynchrony, this study included three aims to assess;1) the global contraction variation in left ventricle (GCV) in normal patients compared with the baseline of patients with cardiac resynchronization therapy (CRT).2) the GCV compared with left ventricular ejection fraction (EF).3) response to CRT using GCV
Method: 25 patients (Gr-N) were identified by normal 12-lead electrocardiogram (ECG). 14 CRT patients (Gr-CRT) were identified and divided into two groups by EF recovery from the baseline; 7 patients (Gr-G) with increased EF, and 7 patients (Gr-P) with decreased EF.256-slice CT was used with common helical protocol .Images were reconstructed at 20 phases(3mm-thickness) on one beat. We developed a method to determine the GCV automatically.The sampling points were placed on 360 degrees of endocardial border from apex to base. The point which was most close to the center of left ventricular (LV) cavity was defined as the 100% contraction (MaxC). Regional points with MaxC were summed at each phase. Using histogram, the maximum contraction was defined as %MC which was standardized by whole points and the standard deviation (SD) was calculated as GCV(%CSD) which was standardized by mean heart rate. %MC, %CSD and EF by CT and QRS by ECG were investigated.We compared Gr-N and the baseline in Gr-CRT(Gr-preCRT) and also compared pre- and post-CRT in Gr-G and Gr-P. Simple liner regression was used to assess the relationship between EF and %CSD
Results: EF and %MC were greater in Gr-N than in Gr-preCRT (78.8+-5.6, 33.4+-16.0, 81.5+-7.9, 50.5+-14.3, p<0.001). %CSD and QRS were shorter in Gr-N than in Gr-preCRT(5.8+-1.8, 21.1+-6.1, 97.2+-8.3, 162.4+-20.5, p<0.001).%CSD was in inverse proportion to EF(r20.89, p<0.001).In Gr-G at pre and post-CRT, EF and %MC were increased (31.7 +- 15.6 to 57.1+-22.8 p<0.001, 43.9+-10.6 to 64.1+-14.3, p<0.05). %CSD and QRS were reduced (22.4+-4.0 to 12.5+-3.5, p<0.001, 163.7+-19.1 to 123.6+-41.6, p<0.05). In Gr-P, EF was significantly reduced at post CRT (35.1+-17.2 to 24.8 +-10.1, p<0.05).
Conclusion: %CSD would be a good predictor of conduction dyssynchrony associate with EF. CT could detect cardiac conduction abnormality.
- © 2011 by American Heart Association, Inc.