The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada; Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, Toronto, Ontario, Canada.
The Hull Family Cardiac Fibrillation Management Laboratory, Toronto General Hospital, Toronto, Ontario, Canada.
Can J Cardiol. 2021 Nov;37(11):1808-1817. doi: 10.1016/j.cjca.2021.07.013. Epub 2021 Jul 29.
We developed a multi-axes lead (Max) incorporating 4 electrodes arranged at the lead-tip, organized in an equidistant tetrahedron. Here, we studied Max performance in sensing, pacing, and activation wavefront-direction analysis.
Sixteen explanted animal hearts (from 7 pigs, 7 sheep, and 2 rabbits) were used. Pacing threshold was tested from all axes of Max from right-ventricular (RV) apex before and after simulated dislodgement. In addition, conduction-system pacing was performed in sheep heart preparations from all axes of Max. Sensing via Max positioned at RV apex was tested during sinus rhythm (SR), pacing from RV and left-ventricular (LV) free-wall, and ventricular fibrillation (VF). Max-enabled voltage (Max), defined as the largest span of the sensed electric field loop, was compared with traditional lead-tip voltage detection.
Pacing: Max minimized change in pacing threshold owing to lead dislodgement (average voltage change 0.2 mV; 95% confidence interval [CI], -0.5 to 0.9), using multiple bipoles available for pacing. In animals with high conduction system-pacing thresholds (> 2 mV) in 1 or more bipoles (3 of 7), acceptable thresholds (< 1 mV) were demonstrated in an average of 2.5 remaining bipoles. Sensing: Max of SR and VF was consistently higher than the highest bipolar voltage (voltage difference averaged -0.18 mV, 95% CI, -0.28 to -0.07), P = 0.001). Electric field-loop geometry consistently differentiated ventricular activation in SR from that during pacing from RV and LV free walls.
The multi-axes Max electrode showed advantages in pacing, sensing, and mapping and has the potential to allow for improvements in lead-electrode technology for cardiac-implanted electronic devices.
我们开发了一种多轴导联（Max），它包含 4 个电极，排列在导联尖端，呈等距四面体排列。在这里，我们研究了 Max 在感知、起搏和激活波前方向分析中的性能。
使用了 16 个动物心脏（来自 7 头猪、7 只羊和 2 只兔子）。在模拟脱位前后，从右心室（RV）心尖测试了 Max 的所有轴的起搏阈值。此外，还在绵羊心脏标本中从 Max 的所有轴进行了传导系统起搏。在窦性节律（SR）、RV 和左心室（LV）游离壁起搏以及室性颤动（VF）期间，通过位于 RV 心尖的 Max 进行了感知测试。Max 感知能力（Max）定义为所感知电场环的最大跨度，与传统的导联尖端电压检测进行了比较。
起搏：Max 最大限度地减少了由于导联脱位引起的起搏阈值变化（平均电压变化 0.2 mV；95%置信区间 [CI]，-0.5 至 0.9），同时使用了多个可用于起搏的双极。在 1 个或多个双极起搏阈值较高（7 个中有 3 个）的动物中，在其余 2.5 个双极中，可获得可接受的阈值（<1 mV）。感知：SR 和 VF 时的 Max 始终高于最高双极电压（电压差平均为-0.18 mV，95%CI，-0.28 至-0.07），P = 0.001）。电场环几何形状始终可区分 SR 中的心室激活与 RV 和 LV 游离壁起搏时的激活。
多轴 Max 电极在起搏、感知和映射方面具有优势，并有潜力改善心脏植入电子设备的导联电极技术。
