Brouwer Tom F, Smeding Lonneke, Berger Wouter R, Driessen Antoine H G, DE Groot Joris R, Wilde Arthur A M, Knops Reinoud E
Department of Clinical and Experimental Cardiology, Amsterdam, the Netherlands.
Department of Cardiothoracic Surgery, Heart Center, Amsterdam Medical Center, University of Amsterdam, Amsterdam, the Netherlands.
J Cardiovasc Electrophysiol. 2017 Jun;28(6):674-676. doi: 10.1111/jce.13195. Epub 2017 Apr 4.
The objective of this study was to assess feasibility of ventricular pacing and thresholds from within the substernal space to examine a new extravascular ICD configuration with pacing capabilities.
In patients undergoing midline sternotomy, a duodecapolar diagnostic pacing catheter was positioned in the substernal space anterior to the pericardium, and a cutaneous patch in left lateral position. Different unipolar and bipolar pacing configurations were assessed. Strength-duration curves were performed to identify the optimal output, starting at 25 mA with a pulse width of 10 milliseconds.
Eight patients with mean age 69 ± 9 years were included. In 5, ventricular capture was achieved in ≥1 configuration. The mean bipolar pacing thresholds at PW 10, 5, 3, 1 milliseconds were 12.4 ± 3.7 mA (5 patients), 13.3 ± 5.8 mA (3 patients), 18.3 ± 5.7 mA (3 patients), and 25 ± 0 mA (2 patients), respectively. The 60-mm electrode spacing was the most successful bipolar configuration. Unipolar pacing was successful in 3 out of 4 patients with mean thresholds of 10 ± 0 mA at 10 milliseconds (3 patients), 15 ± 0 mA at 5 milliseconds (3 patients), 16.7 ± 2.9 mA at 3 milliseconds (3 patients), and 20 ± 7.1 mA at 1 milliseconds (2 patients).
Ventricular pacing from the substernal space in patients with midline sternotomy is feasible. Closed sternum studies are needed to determine pacing thresholds more accurately.
本研究的目的是评估经胸骨后间隙进行心室起搏及测定阈值的可行性，以研究一种具有起搏功能的新型血管外植入式心律转复除颤器（ICD）配置。
在接受正中开胸手术的患者中，将一根十二极诊断性起搏导管置于心包前方的胸骨后间隙，并在左侧卧位放置一个皮肤贴片。评估了不同的单极和双极起搏配置。从25 mA开始，脉冲宽度为10毫秒，进行强度-时间曲线测定以确定最佳输出。
纳入8例平均年龄为69±9岁的患者。其中5例患者至少有一种配置实现了心室夺获。在脉冲宽度为10、5、3、1毫秒时，平均双极起搏阈值分别为12.4±3.7 mA（5例患者）、13.3±5.8 mA（3例患者）、18.3±5.7 mA（3例患者）和25±0 mA（2例患者）。60毫米的电极间距是最成功的双极配置。4例患者中有3例单极起搏成功，在10毫秒时平均阈值为10±0 mA（3例患者），5毫秒时为15±0 mA（3例患者），3毫秒时为16.7±2.9 mA（3例患者），1毫秒时为20±7.1 mA（2例患者）。
正中开胸手术患者经胸骨后间隙进行心室起搏是可行的。需要进行胸骨闭合研究以更准确地确定起搏阈值。
