Abstract 14884: Association of Pacing Induced Septal Mechanical Propagation Delay With Decline in Left Ventricular Function After Atrioventricular Node Ablation
Background: Chronic right ventricular (RV) pacing has variable and unpredictable effects on left ventricular (LV) function. Patients with atrial fibrillation (AF) requiring atrioventricular node (AVN) ablation become RV pacer dependent.
Objectives: To test the hypothesis that a specific mechanical activation pattern can be identified using speckle tracking strain echocardiography that is associated with deterioration of LV function in RV paced patients after AVN ablation.
Methods: We studied 91 refractory AF patients with normal ejection fraction (EF) at baseline who had AVN ablation. Echocardiography was performed before, shortly after and ≥ 2 years after AVN ablation. Speckle tracking longitudinal strain determined regional mechanical activation and strain propagation times from apical four chamber views and anteroseptal posterior wall delay from short axis views after start of RV pacing (median of 4.4 months).
Results: Patient’s age was 71±9 years, with baseline EF of 59±5 %. After 28 months of follow-up, 28 patients (31%) had ≥5% absolute decrease in EF. In a univariable logistic regression, septal and lateral mechanical propagation delay (MPD), global longitudinal strain, anteroseptal posterior wall delay, β-blockers use and native QRS width were associated with a ≥5% reduction in EF (all p<0.05). In multivariable analysis, only septal MPD delay was independently associated with a ≥5% absolute decrease in EF (p=0.003). Using ROC curve analysis, septal MPD > 50 ms had a sensitivity of 81% and a specificity of 88% associated with a ≥5% reduction in EF over long term follow up (AUC 0.84, 95% CI 0.745 to 0.913; P=<0.0001).
Conclusions: In patients with normal EF and refractory AF undergoing AVN ablation and RV pacing, speckle tracking septal MPD is significantly associated with subsequent LV dysfunction. This observation might help selection of patients for biventricular pacing following AVN and warrants further study.
- © 2013 by American Heart Association, Inc.