School of Clinical Medicine, University of Cambridge, Cambridge, UK.
Europace. 2013 Sep;15(9):1249-58. doi: 10.1093/europace/eut038. Epub 2013 Feb 28.
To develop electrocardiogram (ECG) tools to quantify the number of sources for atrial fibrillation (AF), i.e. spatially stable rotors and focal impulses, and whether they lie in right or left atrium. Intracardiac mapping has recently shown that paroxysmal and persistent AF is sustained by rotors or focal sources that are stable in location and thus targets for limited ablation [focal impulse and rotor modulation (FIRM)] to eliminate AF. Importantly, the numbers and locations of concurrent sources determine both the complexity of AF and the approach for ablation.
In 36 AF patients (n = 29 persistent, 63 ± 9 years) in the CONventional ablation with or without Focal Impulse and Rotor Modulation (CONFIRM) trial, we developed phase lock (PL) to quantify spatial repeatability of ECG 'F-waves' between leads over time. Phase lock spectrally quantifies the angle θ between F-wave voltages in planes formed by ECG leads I, aVF, and V1 at successive points in time. We compared PL with ECG spectral dominant frequency (DF) and organizational index (OI) to characterize stable rotors and focal sources validated by intracardiac FIRM mapping. Focal impulse and rotor modulation ablation alone at ≤3 sources acutely terminated and rendered AF non-inducible or substantially slowed AF in 31 of 36 patients. Receiver operating characteristics of PL for this endpoint had area under the curve (AUC) = 0.72, and the optimum cut-point (PL = 0.09) had 74% sensitivity, 92% positive predictive value (PPV). Receiver operating characteristics areas for OI and DF were 0.50 and 0.58, respectively. Left (n = 28) or right (n = 3) atrial sources were localized by PL with AUC = 0.85, sensitivity 100%, PPV 30%, and negative predictive value 100%. Spectral DF provided AUC = 0.79. Notably, PL did not comigrate with diagnosis of paroxysmal or persistent AF (P = NS), unlike ECG DF.
The novel metric of ECG PL identifies patients with fewer (≤3) or greater numbers of stable rotors/focal sources for AF, validated by intracardiac FIRM mapping, and localized them to right or left atria. These data open the possibility of using 12-lead ECG analyses to classify AF mechanistically and plan procedures for right- or left-sided FIRM ablation.
开发心电图（ECG）工具来量化心房颤动（AF）的源数量，即空间稳定的转子和灶性冲动，以及它们位于左心房还是右心房。心脏内映射最近表明，阵发性和持续性 AF 由位置稳定的转子或灶性源维持，因此是有限消融的目标[灶性冲动和转子调制（FIRM）]以消除 AF。重要的是，并发源的数量和位置决定了 AF 的复杂性和消融的方法。
在 CONventional ablation with or without Focal Impulse and Rotor Modulation（CONFIRM）试验中的 36 名 AF 患者（n = 29 名持续性，63 ± 9 岁）中，我们开发了相位锁定（PL）来量化 ECG“F-波”在 leads 之间随时间的空间重复性。相位锁定通过在 ECG 导联 I、aVF 和 V1 形成的平面中，以连续时间点之间的 F 波电压之间的角度 θ 来对频谱进行量化。我们比较了 PL 与 ECG 频谱主导频率（DF）和组织指数（OI），以表征由心脏内 FIRM 映射验证的稳定转子和灶性源。单独进行 FIRM 消融≤3 个源可在 36 名患者中的 31 名中急性终止并使 AF 不能诱发或使 AF 明显减慢。PL 对该终点的受试者工作特征曲线（AUC）为 0.72，最佳截断点（PL = 0.09）的灵敏度为 74%，阳性预测值（PPV）为 92%。OI 和 DF 的接收器操作特征面积分别为 0.50 和 0.58。PL 以 AUC = 0.85、灵敏度 100%、PPV 30%和阴性预测值 100%定位左（n = 28）或右（n = 3）心房源。频谱 DF 的 AUC = 0.79。值得注意的是，PL 与阵发性或持续性 AF 的诊断并不一致（P = NS），而不像 ECG DF。
新的 ECG PL 指标可识别出 AF 中稳定的转子/灶性源数量较少（≤3）或较多的患者，并通过心脏内 FIRM 映射进行验证，并将其定位到右心房或左心房。这些数据为使用 12 导联 ECG 分析对 AF 进行机制分类和规划右侧或左侧 FIRM 消融提供了可能性。
