Abstract 15826: Impact of the Type of Pattern of Intra-LV Dyssynchrony in Patients Randomized to Two Modes of CRT (LV vs. BiV): Insights From the Evaluation of Resynchronization Therapy for Heart Failure (EARTH) Trial
Background: Cardiac Resynchronization Therapy (CRT) is accepted for patients (pts) with heart failure (HF) and wide QRS. Whether the pattern of contraction (septum or lateral wall first) is important for response and whether the type of CRT (LV or BiV) should be individualized according to the type of pattern encountered remain unanswered.
Methods and Results: GREATER-EARTH is a multicenter, double-blinded randomized trial with a cross-over design aiming to determine whether CRT with LV pacing provides a superior response to BiV pacing. 121 HF pts (NYHA II-IV), LVEF: 24±7% and QRS: 155±23ms were randomized and an echocardiography was performed at baseline and after 6months of CRT with both pacing modes. Two patterns of intra-LV contraction were observed by TDI: the “common pattern” (CP) where the septum is contracting before the lateral wall and the “reverse pattern” (RP) where the lateral wall is contracting before the septum. 104 pts have complete follow-up data: 49CP and 55 RP. At baseline, RP was associated with increased LVESVol (166±56 vs. 151±86mL) and LVEDVol (217±63 199±52mL) but similar LVEF (25±7 and 24±5). At follow-up: TABLE
Conclusions: Dyssynchrony is generally reported in absolute values (all positive) despite the fact that 2 opposite patterns of intra-LV exist in pts with low LVEF: a common pattern where the lateral wall contracts after the septum and a reverse pattern (lateral wall before septum). The reverse pattern was associated with larger LV volumes (even with similar LVEF) compared to the common pattern. Contrary to our hypothesis, improvement in LV function and remodelling was similar with BIV and LV-CRT, in both patterns of mechanical dyssynchrony.
- © 2010 by American Heart Association, Inc.