Nairn Deborah, Lehrmann Heiko, Müller-Edenborn Björn, Schuler Steffen, Arentz Thomas, Dössel Olaf, Jadidi Amir, Loewe Axel
Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Department of Electrophysiology, University-Heart-Center Freiburg-Bad Krozingen, Bad Krozingen, Germany.
Front Physiol. 2020 Nov 26;11:575846. doi: 10.3389/fphys.2020.575846. eCollection 2020.
Presence of left atrial low voltage substrate in bipolar voltage mapping is associated with increased arrhythmia recurrences following pulmonary vein isolation for atrial fibrillation (AF). Besides local myocardial fibrosis, bipolar voltage amplitudes may be influenced by inter-electrode spacing and bipole-to-wavefront-angle. It is unclear to what extent these impact low voltage areas (LVA) in the clinical setting. Alternatively, unipolar electrogram voltage is not affected by these factors but requires advanced filtering. To assess the relationship between bipolar and unipolar voltage mapping in sinus rhythm (SR) and AF and identify if the electrogram recording mode affects the quantification and localization of LVA. Patients ( = 28, 66±7 years, 46% male, 82% persistent AF, 32% redo-procedures) underwent high-density (>1,200 sites, 20 ± 10 sites/cm, using a 20-pole 2-6-2 mm-spaced Lasso) voltage mapping in SR and AF. Bipolar LVA were defined using four different thresholds described in literature: <0.5 and <1 mV in SR, <0.35 and <0.5 mV in AF. The optimal unipolar voltage threshold resulting in the highest agreement in both unipolar and bipolar mapping modes was determined. The impact of the inter-electrode distance (2 vs. 6 mm) on the correlation was assessed. Regional analysis was performed using an 11-segment left atrial model. Patients had relevant bipolar LVA (23 ± 23 cm at <0.5 mV in SR and 42 ± 26 cm at <0.5 mV in AF). 90 ± 5% (in SR) and 85 ± 5% (AF) of mapped sites were concordantly classified as high or low voltage in both mapping modes. Discordant mapping sites located to the border zone of LVA. Bipolar voltage mapping using 2 vs. 6 mm inter-electrode distances increased the portion of matched mapping points by 4%. The unipolar thresholds (y) which resulted in a high spatial concordance can be calculated from the bipolar threshold (x) using following linear equations: = 1.06 + 0.26 ( = 0.994) for SR and = 1.22 + 0.12 ( = 0.998) for AF. Bipolar and unipolar voltage maps are highly correlated, in SR and AF. While bipole orientation and inter-electrode spacing are theoretical confounders, their impact is unlikely to be of clinical importance for localization of LVA, when mapping is performed at high density with a 20-polar Lasso catheter.
双极电压标测中左心房低电压基质的存在与房颤（AF）肺静脉隔离术后心律失常复发增加相关。除了局部心肌纤维化外，双极电压幅度可能受电极间距和双极与波前夹角的影响。在临床环境中，这些因素对低电压区域（LVA）的影响程度尚不清楚。另外，单极心电图电压不受这些因素影响，但需要先进的滤波。为了评估窦性心律（SR）和AF中双极和单极电压标测之间的关系，并确定心电图记录模式是否影响LVA的量化和定位。患者（n = 28，66±7岁，46%为男性，82%为持续性AF，32%为再次手术）在SR和AF中接受高密度（>1200个位点，20±10个位点/cm，使用20极2 - 6 - 2 mm间距的Lasso导管）电压标测。双极LVA使用文献中描述的四种不同阈值定义：SR中<0.5 mV和<1 mV，AF中<0.35 mV和<0.5 mV。确定了在单极和双极标测模式下导致最高一致性的最佳单极电压阈值。评估了电极间距（2 vs. 6 mm）对相关性的影响。使用11段左心房模型进行区域分析。患者存在相关双极LVA（SR中<0.5 mV时为23±23 cm，AF中<0.5 mV时为42±26 cm）。在两种标测模式下，90±5%（SR中）和85±5%（AF中）的标测位点被一致分类为高电压或低电压。不一致的标测位点位于LVA的边界区域。使用2 vs. 6 mm电极间距的双极电压标测使匹配标测点的比例增加了4%。可使用以下线性方程从双极阈值（x）计算出导致高空间一致性的单极阈值（y）：SR中y = 1.06 + 0.26x（r = 0.994），AF中y = 1.22 + 0.12x（r = 0.998）。在SR和AF中，双极和单极电压图高度相关。虽然双极方向和电极间距是理论上的混杂因素，但当使用20极Lasso导管进行高密度标测时，它们对LVA定位的影响在临床上不太可能具有重要意义。
