OBJECTIVES This study assessed the impact of right-atrial (RA) pacing on left-atrial (LA) physiology and clinical outcome. BACKGROUND Data for the effects of RA pacing on LA synchronicity, function, and structure after cardiac resynchronization therapy (CRT) are scarce. METHODS The effect of RA pacing on LA function, morphology, and synchronicity was assessed in a prospective imaging cohort of heart failure (HF) patients in sinus rhythm with a guideline-based indication for CRT. Additionally, in a retrospective outcome cohort of consecutive HF patients undergoing CRT implantation, the relationship to RA pacing was assessed using various outcome endpoints. High versus low atrial pacing burden was defined as atrial pacing above or below 50% in both cohorts. RESULTS A total of 36 patients were included in the imaging cohort (68 ± 11 years of age). Six months after CRT, patients with high RA pacing burden showed less improvement in LA maximum and minimum volumes and total emptying fraction (p < 0.05). Peak atrial longitudinal strain and reservoir and booster strain rates but not conduit strain rate improved after CRT in patients with low RA pacing burden but worsened in patients with high RA pacing burden (p < 0.05 for all). A high RA pacing burden induced significant intra-atrial dyssynchrony (maximum opposing wall delay: 44 ± 13 ms vs. 97 ± 17 ms, respectively; p = 0.022). A total of 569 patients were included in the outcome cohort. After covariate adjustments were made, a high RA pacing burden was associated with reduced LV reverse remodeling (β = 8.738; 95% confidence interval [CI]: 3.101 to 14.374; p = 0.002) and new-onset or recurrent atrial fibrillation (41% vs. 22%, respectively, at a median of 31 months [range 22 to 44 months follow-up]; p < 0.001). There were no differences in time to first HF hospitalization or all-cause mortality (p = 0.185) after covariate adjustment. However, in a recurrent event analysis, HF readmissions were more common in patients exposed to a high RA pacing burden (p = 0.003). CONCLUSIONS RA pacing in CRT patients negatively influences LA morphology, function, and synchronicity, which is associated with worse clinical outcome, including diminished LV reverse remodeling, increased risk for new-onset or recurrent AF and heart failure readmission. Strategies reducing RA pacing burden may be warranted.

中文翻译：

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在心脏再同步治疗中，RA起搏对LA功能和临床结果的有害影响。

目的本研究评估了右心房（RA）起搏对左心房（LA）生理和临床结局的影响。背景技术关于在心脏再同步治疗（CRT）后RA起搏对LA同步性，功能和结构的影响的数据很少。方法在前瞻性影像学检查中，以窦性心律的心衰（HF）患者的前瞻性影像学队列评估RA起搏对LA功能，形态和同步性的影响，并以基于CRT的指征为基础。此外，在连续进行CRT植入的HF患者的回顾性结局队列中，使用各种结局终点评估了与RA起搏的关系。高和低心房起搏负担定义为两个队列中高于或低于50％的心房起搏。结果总共有36名患者被纳入影像学队列（68±11岁）。CRT后六个月，高RA起搏负担的患者在LA最大和最小容积以及总排空分数方面的改善较少（p <0.05）。RA起搏负荷低的患者在进行CRT后，峰值心房纵向应变和储液和助推器应变率增加，但导管应变率却没有改善，但RA起搏负荷高的患者则恶化了（p均<0.05）。较高的RA起搏负担会导致严重的心房内不同步（最大相对壁延迟：分别为44±13 ms和97±17 ms； p = 0.022）。结果队列共纳入569例患者。进行协变量调整后，较高的RA起搏负担与降低的左室反向重塑有关（β= 8.738； 95％置信区间[CI]：3.101至14.374； p = 0.002）和新发或复发性心房颤动（41％）相比22％中位时间分别为31个月[随访范围为22到44个月]；p <0.001）。协变量调整后，首次HF住院时间或全因死亡率（p = 0.185）没有差异。然而，在复发事件分析中，HF再次入院在暴露于高RA起搏负担的患者中更为常见（p = 0.003）。结论CRT患者的RA起搏会对LA的形态，功能和同步性产生负面影响，这与较差的临床结果相关，包括LV逆向重构减少，新发或复发性AF的风险增加以及心力衰竭重新入院。可以采取减少RA起搏负担的策略。185）进行协变量调整后。然而，在复发事件分析中，HF再次入院在暴露于高RA起搏负担的患者中更为常见（p = 0.003）。结论CRT患者的RA起搏会对LA的形态，功能和同步性产生负面影响，这与较差的临床结果相关，包括LV逆向重构减少，新发或复发性AF的风险增加以及心力衰竭重新入院。可以采取减少RA起搏负担的策略。185）进行协变量调整后。然而，在复发事件分析中，HF再次入院在暴露于高RA起搏负担的患者中更为常见（p = 0.003）。结论CRT患者的RA起搏会对LA的形态，功能和同步性产生负面影响，这与较差的临床结果相关，包括LV逆向重构减少，新发或复发性AF的风险增加以及心力衰竭重新入院。可以采取减少RA起搏负担的策略。新发或复发性房颤和心力衰竭再入院的风险增加。可以采取减少RA起搏负担的策略。新发或复发性房颤和心力衰竭再入院的风险增加。可以采取减少RA起搏负担的策略。