Barton C, Manning J E, Batson N
Department of Emergency Medicine, University of North Carolina-Chapel Hill, USA.
Ann Emerg Med. 1996 May;27(5):610-6. doi: 10.1016/s0196-0644(96)70165-8.
To determine whether the computer-derived measures of median frequency or peak amplitude of ventricular fibrillation (VF), obtained by fast Fourier transform of the VF waveform, change during selective aortic arch perfusion in a canine model of cardiac arrest.
Eight mongrel dogs (including 4 control animals) were sedated, intubated, catheterized, and instrumented to record the electrocardiogram (digitally at 100 Hz, filtered with a finite impulse response filter at 2 Hz), right atrial pressure, and aortic pressure during resuscitation in a model of VF-induced cardiac arrest. After 10 minutes of VF-induced arrest, cardiopulmonary resuscitation (CPR) with a mechanical chest compression device was initiated. Beginning 2 minutes later, the 4 study animals received, every 2 minutes, 45 seconds of selective aortic arch perfusion (SAAP) with autologous blood infusions under high pressure. Defibrillation was attempted after 3 minutes of CPR and every minute thereafter. Both study and control groups received standard-dose epinephrine (.01 mg/kg) every 3 minutes by means of an intraaortic catheter. The median frequency, peak amplitude, and coronary perfusion pressure (CPP) during the 5-second period just before defibrillation were obtained with the use of computer algorithms.
All SAAP animals and 1 control animal were resuscitated. Baseline measures of median frequency (8.4 +/- 1.5 versus 6.6 +/- 1.0 Hz) and peak amplitude (.18 +/- .05 versus .36 +/- .13 mV) were not different between the SAAP and control groups, respectively, at the start of CRP. SAAP infusion resulted in significant increases in the SAAP group compared with the control group: median frequency, 9.6 +/- .4 versus 7.3 +/- 1.4 Hz; peak amplitude, .74 +/- .21 versus .39 +/- .15 mV; and CPP, 40.5 +/- 7.1 versus 18.0 +/- 15.0 mm Hg, respectively. Median frequency correlated with CPP (r2 = .67). Peak amplitude did not correlate with CPP (r2 = .06).
Median frequency and peak amplitude increase with SAAP during cardiac arrest in a canine model. This method of resuscitation was reliable in allowing restoration of a stable perfusing rhythm after defibrillation. Changes in measures of peak amplitude and median frequency may reflect interventions that enhance the likelihood of successful defibrillation and may thereby offer a noninvasive means of monitoring interventions during cardiac arrest.
通过对室颤（VF）波形进行快速傅里叶变换获得计算机推导的室颤中位频率或峰值幅度测量值，以确定在犬心脏骤停模型的选择性主动脉弓灌注过程中这些测量值是否会发生变化。
八只杂种犬（包括4只对照动物）接受镇静、插管、导管插入，并在VF诱导的心脏骤停模型复苏过程中进行仪器监测，以记录心电图（以100Hz数字记录，用2Hz的有限脉冲响应滤波器滤波）、右心房压力和主动脉压力。在VF诱导的心脏骤停10分钟后，启动使用机械胸外按压装置的心肺复苏（CPR）。2分钟后开始，4只研究动物每2分钟接受45秒的选择性主动脉弓灌注（SAAP），通过高压输注自体血。在CPR 3分钟后及此后每分钟尝试除颤。研究组和对照组均通过主动脉内导管每3分钟接受标准剂量肾上腺素（0.01mg/kg）。使用计算机算法获得除颤前5秒期间的中位频率、峰值幅度和冠状动脉灌注压（CPP）。
所有接受SAAP的动物和1只对照动物均复苏成功。在CRP开始时，SAAP组和对照组的基线中位频率测量值（分别为8.4±1.5对6.6±1.0Hz）和峰值幅度测量值（分别为0.18±0.05对0.36±0.13mV）无差异。与对照组相比，SAAP输注导致SAAP组显著增加：中位频率，9.6±0.4对7.3±1.4Hz；峰值幅度，0.74±0.21对0.39±0.15mV；以及CPP，分别为40.5±7.1对18.0±15.0mmHg。中位频率与CPP相关（r2 = 0.67）。峰值幅度与CPP不相关（r2 = 0.06）。
在犬模型心脏骤停期间，SAAP可使中位频率和峰值幅度增加。这种复苏方法在除颤后恢复稳定灌注节律方面是可靠的。峰值幅度和中位频率测量值的变化可能反映了增强成功除颤可能性的干预措施，从而可能提供一种在心脏骤停期间监测干预措施的非侵入性方法。
