Abstract 11371: A Novel, Comprehensive RV Strain Analysis: Frequently Encountered Ventricular Activation Abnormalities in the Systemic Right Ventricle

Abstract

Introduction: To assess the utility of 18 segment (SEG) RV regional strain analysis, patients with d-transposition of the great artery (dTGA) post atrial switch operation were studied. They rely on a systemic right ventricle (SRV) that frequently suffers from progressive failure and an array of conduction abnormalities. Altered conduction patterns precipitate abnormal activation and may lead to activation induced heart failure (AIHF). AIHF has been previously identified in a failing LV population by a classic strain pattern of activation delay (early contraction in one ventricular wall along with early bulge followed by late contraction in the opposing wall) and is an excellent predictor of CRT response. Specific goals were: (1) to compare strain measures to other echo markers in our subjects; (2) determine if strain analysis using our 18-SEG model adds significant value, (3) discover the frequency of the classic pattern for AIHF in this SRV population. Hypothesis: The 18-SEG RV strain analysis will provide an improved understanding of RV regional mechanics and show that many SRV patients possess a pattern consistent with AIHF.

Methods: Seventeen dTGA and 25 young, healthy controls were studied using a previously described novel 3 apical view, 18-SEG RV model.

Results: Results for controls were previously reported. In the SRV group, the mean age was 34.3 years (range 22-49, 65% male) with 41% NYHA class II and 47% classes III/IV. All SRV subjects were LV paced (41%) or had RBBB/IRBBB (59%) by ECG. Global peak longitudinal systolic strain (GPLSS) was diminished vs controls (-10.8±3.6%; -23.5±2.4%; p<0.0001). Across all subjects, GPLSS related well to TAPSE (r²=0.82). Using timing analysis, standard deviation of time to peak intervals were elevated in the SRV vs controls (92.1±30.5 ms; 26.7±8.15 ms; p<0.0001). A classic pattern was seen in 11/17 of SRV subjects. These patterns would have been missed in 4/11 based on the 6-SEG model.

Conclusion: RV function and timing patterns were different in normal and SRV populations. Importantly, the classic pattern for AIHF that may predict response to CRT was seen in 65% of SRV subjects. Examining this population with our comprehensive RV approach revealed more potentially important information than the traditional method.