Department of Translational Medicine, Clinical Cardiology, Università del Piemonte Orientale, Azienda Ospedaliera Universitaria "Maggiore della Carità", Corso Mazzini 18, 28100, Novara, Italy.
Clin Res Cardiol. 2018 Apr;107(4):329-337. doi: 10.1007/s00392-017-1188-9. Epub 2017 Nov 27.
Diastolic dysfunction promotes atrial fibrillation (AF) inducing left atrial (LA) remodeling, with chamber dilation and fibrosis. Predominance of LA phasic conduit (LAC) function should reflect not only chamber alterations but also underlying left ventricular (LV) filling impairment. Thus, LAC was tested as possible predictor of early AF relapse after electrical cardioversion (EC).
96 consecutive patients, who underwent EC for persistent non-valvular AF, were prospectively enrolled. Immediately after successful EC (3 h ± 15 min), an echocardiographic apical four-chamber view was acquired with transmitral velocities, annular tissue Doppler and simultaneous LV and LA three-dimensional full-volume datasets. Then, from LA-LV volumetric curves we computed LAC as: [(LV maximum - LV minimum) - (LA maximum - LA minimum) volume], expressed as % LV stroke volume. LA pump, immediately post-EC, was assumed and verified as being negligible. Sinus rhythm persistence at 1 month was checked with ECG-Holter monitoring.
At 1 month 62 patients were in sinus rhythm and 34 in AF. AF patients presented pre-EC higher E/é values (p = 0.012), no major LA volume differences (p = NS), but a stiffer LV cavity (p = 0.012) for a comparable LV capacitance (p = 0.461). Conduit contributed more (p < 0.001) to LV stroke volume in AF subpopulation. Multiple regression revealed LAC as the most significant AF predictor (p = 0.013), even after correction for biometric characteristics and pharmacotherapy (p = 0.008).
Our data suggest that LAC larger contribution to LV filling soon after EC reflects LA-LV stiffening, which skews atrioventricular interaction leading to AF perpetuation and makes conduit dominance a powerful predictor of early AF recurrence.
舒张功能障碍可导致左心房（LA）重构，引起心房颤动（AF），导致心房扩张和纤维化。LA 相腔（LAC）功能的主导地位不仅应反映腔室改变，还应反映潜在的左心室（LV）充盈受损。因此，我们测试了 LAC 是否可以作为电复律（EC）后早期 AF 复发的预测因子。
前瞻性纳入 96 例因持续性非瓣膜性 AF 而行 EC 的连续患者。在成功进行 EC 后立即（3 小时±15 分钟），获取心尖四腔切面的超声心动图，测量二尖瓣血流速度、环组织多普勒速度，并同时获取 LV 和 LA 三维全容积数据集。然后，我们从 LA-LV 容积曲线上计算 LAC 为：[（LV 最大- LV 最小）-（LA 最大- LA 最小）容积]，以 LV stroke volume 的百分比表示。假设 LA 泵在 EC 后即刻可以忽略不计，并对其进行验证。通过心电图- Holter 监测检查 1 个月时窦性心律的持续情况。
1 个月时，62 例患者为窦性心律，34 例为 AF。AF 患者在 EC 前具有更高的 E/é 值（p=0.012），LA 容积无明显差异（p=NS），但 LV 腔室更僵硬（p=0.012），LV 电容相似（p=0.461）。在 AF 亚组中，LAC 对 LV stroke volume 的贡献更大（p<0.001）。多元回归显示，LAC 是 AF 的最显著预测因子（p=0.013），即使在校正了生物学特征和药物治疗后（p=0.008）。
我们的数据表明，EC 后不久 LAC 对 LV 充盈的贡献更大，反映了 LA-LV 的僵硬，这种僵硬改变了房室相互作用，导致 AF 持续存在，并使腔道优势成为早期 AF 复发的有力预测因子。
