Hsia P W, Suresh G, Allen C A, Harrington G, Maskal S, Fain E, Damiano R J
Department of Biomedical Engineering, Medical College of Virginia, Virginia Commonwealth University, Richmond, USA.
Pacing Clin Electrophysiol. 1996 Nov;19(11 Pt 1):1537-47. doi: 10.1111/j.1540-8159.1996.tb03178.x.
The heart has been shown to be more susceptible to defibrillation at a higher absolute ventricular fibrillation voltage (AVFV) measured on the surface ECG. This study evaluated in a closed-chest canine model (n = 7) the clinical applicability of using a real-time VF waveform analysis system using an electrogram defined between the generator can and an RV endocardial electrode. Under fluoroscopic guidance, superior vena cava and RV spring coil catheter electrodes were inserted through the external jugular vein. A subcutaneous patch was placed on the left chest. A two-parameter tracking algorithm was used to dynamically identify the high AVFV area, and a biphasic shock was triggered synchronously at the next peak. The performance of this new peak shock method (PSM) was compared to the conventional method of shocking at a fixed time in 175 paired trials. Five shocks per voltage and five voltages per animal were randomized between the two methods to permit the generation of sigmoidal dose response curves for the estimation of 50% (E50), 75% (E75), and 100% (E100) success energies. Induction of VF and discharge voltage were kept constant while energy delivered, impedance (R), and AVFV at the point of shock were measured. Energy (8.63 +/- 0.40 vs 8.64 +/- 0.40 J), R (48.60 +/- 0.30 vs 48.59 +/- 0.30 omega), and current (7.50 +/- 0.18 vs 7.51 +/- 0.16 A) were not significantly different between trials for either the conventional or the PSM. The time from the onset of VF until the defibrillation shock was 7.98 +/- 1.44 seconds. Higher overall successes (46.3% vs 33.1%; P < 0.01) and lower E50, E75, and E100 were observed for the PSM. Finally, the significantly higher AVFV (9.12 +/- 0.32 vs 4.73 +/- 0.34 mV; P < 0.0001) with the peak method suggests that the high VF voltage could be detected as it occurred in real-time. The improved defibrillation success supports the use of this method for nonthoracotomy defibrillation.
研究表明，在体表心电图上测得的较高的绝对室颤电压（AVFV）时，心脏对除颤更敏感。本研究在一个开胸犬模型（n = 7）中评估了使用一种实时室颤波形分析系统的临床适用性，该系统使用在发生器罐和右心室心内膜电极之间定义的电描记图。在透视引导下，通过颈外静脉插入上腔静脉和右心室弹簧圈导管电极。在左胸放置一个皮下贴片。使用双参数跟踪算法动态识别高AVFV区域，并在下一个峰值处同步触发双相电击。在175对试验中，将这种新的峰值电击方法（PSM）的性能与在固定时间电击的传统方法进行了比较。在两种方法之间随机分配每个电压5次电击和每只动物5个电压，以生成S形剂量反应曲线，用于估计50%（E50）、75%（E75）和100%（E100）成功能量。室颤的诱发和放电电压保持恒定，同时测量电击时传递的能量、阻抗（R）和AVFV。传统方法或PSM的试验之间，能量（8.63±0.40 vs 8.64±0.40 J）、R（48.60±0.30 vs 48.59±0.30 Ω）和电流（7.50±0.18 vs 7.51±0.16 A）无显著差异。从室颤发作到除颤电击的时间为7.98±1.44秒。PSM观察到更高的总体成功率（46.3% vs 33.1%；P < 0.01）以及更低的E50、E75和E100。最后，峰值方法显著更高的AVFV（9.12±0.32 vs 4.73±0.34 mV；P < 0.0001）表明，高室颤电压可以在其实时发生时被检测到。除颤成功率的提高支持了这种方法用于非开胸除颤。
