Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, United States of America.
Department of Cardiology, Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.
PLoS One. 2016 Oct 5;11(10):e0163445. doi: 10.1371/journal.pone.0163445. eCollection 2016.
Knowledge of atrial electrophysiological properties is crucial for clinical intervention of atrial arrhythmias and the investigation of the underlying mechanism. This study aims to evaluate the feasibility of a novel noninvasive cardiac electrical imaging technique in imaging bi-atrial activation sequences from body surface potential maps (BSPMs).
The study includes 7 subjects, with 3 atrial flutter patients, and 4 healthy subjects with normal atrial activations. The subject-specific heart-torso geometries were obtained from MRI/CT images. The equivalent current densities were reconstructed from 208-channel BSPMs by solving the inverse problem using individual heart-torso geometry models. The activation times were estimated from the time instant corresponding to the highest peak in the time course of the equivalent current densities. To evaluate the performance, a total of 32 cycles of atrial flutter were analyzed. The imaged activation maps obtained from single beats were compared with the average maps and the activation maps measured from CARTO, by using correlation coefficient (CC) and relative error (RE).
The cardiac electrical imaging technique is capable of imaging both focal and reentrant activations. The imaged activation maps for normal atrial activations are consistent with findings from isolated human hearts. Activation maps for isthmus-dependent counterclockwise reentry were reconstructed on three patients with typical atrial flutter. The method was capable of imaging macro counterclockwise reentrant loop in the right atrium and showed inter-atria electrical conduction through coronary sinus. The imaged activation sequences obtained from single beats showed good correlation with both the average activation maps (CC = 0.91±0.03, RE = 0.29±0.05) and the clinical endocardial findings using CARTO (CC = 0.70±0.04, RE = 0.42±0.05).
The noninvasive cardiac electrical imaging technique is able to reconstruct complex atrial reentrant activations and focal activation patterns in good consistency with clinical electrophysiological mapping. It offers the potential to assist in radio-frequency ablation of atrial arrhythmia and help defining the underlying arrhythmic mechanism.
了解心房的电生理特性对于临床干预心房心律失常和研究潜在机制至关重要。本研究旨在评估一种新型的无创心脏电成像技术在从体表电位图（BSPM）成像双心房激活序列方面的可行性。
该研究包括 7 名受试者，其中 3 名心房扑动患者，4 名正常心房激活的健康受试者。从 MRI/CT 图像获得个体心脏-胸廓几何形状。使用个体心脏-胸廓几何模型通过求解逆问题，从 208 通道 BSPM 中重建等效电流密度。从等效电流密度的时间历程中对应最高峰值的时间点估计激活时间。为了评估性能，共分析了 32 个心房扑动周期。从单心动周期获得的成像激活图与平均图和从 CARTO 测量的激活图进行比较，使用相关系数（CC）和相对误差（RE）。
心脏电成像技术能够成像局灶性和折返性激活。正常心房激活的成像激活图与离体人心的发现一致。在 3 名典型心房扑动患者中重建了依赖峡部的逆时针折返的激活图。该方法能够成像右心房的宏观逆时针折返环，并显示通过冠状窦的心房间电传导。从单心动周期获得的成像激活序列与平均激活图（CC=0.91±0.03，RE=0.29±0.05）和使用 CARTO 的临床心内膜发现具有很好的相关性（CC=0.70±0.04，RE=0.42±0.05）。
无创心脏电成像技术能够重建复杂的心房折返激活和局灶性激活模式，与临床电生理标测具有很好的一致性。它有可能协助心房心律失常的射频消融，并有助于确定潜在的心律失常机制。
