The impact of sick sinus syndrome on flow velocity of the left atrial appendage in patients with atrial fibrillation

Abstract

Abstract Background Sick sinus syndrome (SSS) itself has been suspected as one of potential embolic stroke sources, however, the mechanism remains unclear. Reduced flow velocity of left atrial appendage (LAAFV) plays a major role in thrombus formation in patients with atrial fibrillation (AF). We evaluated the contribution of SSS to LAAFV in patients with AF. Methods We studied 153 consecutive patients (age 69±10, 100 males, 79 paroxysmal AF, CHADS2 score 1.6±1.2) who underwent catheter ablation (CA) for AF at our hospital and our college of medicine. All patients enrolled in this study underwent transesophageal echocardiography (TEE) and transthoracic echocardiography prior to CA. LA global mean voltage and LA activation time were also measured using High-density LA mapping during CA. Clinical characteristics and laboratory data was obtained before CA for AF. SSS was defined as sinus arrest with 3 seconds or more by Holter ECG, or pacemaker implantation due to SSS. Results Reduced LAAFV was associated with old age (R²=0.0783, P=0.0005), female (R²=0.0260, P=0.0285), non-paroxysmal AF (R²=0.1403, P<0.0001), hypertension (R²=0.0226, P=0.0338), history of congestive heart failure (R²=0.0890, P=0.0007), high CHADS2 score (R²=0.1248, P<0.0001), high level of BNP (R²=0.2054, P<0.0001), AF rhythm during TEE (R²=0.1577, P<0.0001), low LV ejection fraction (R²=0.0255, P=0.0488), large LA diameter (R²=0.1544, P<0.0001), high E wave (R²=0.1168, P<0.0001), low LA global mean voltage (R²=0.1775, P<0.0001), long LA activation time (R²=0.1383, P<0.0001) and SSS (n=29, R²=0.0957, P=0.0002). On multiple linear regression analysis, SSS, AF rhythm during TEE, BNP, female was independently related to reduced LAAFV (Table). Conclusion SSS itself might be related to reduced LAAFV in patients with AF.Table