Chorro Francisco J, Millet José, Ferrero Angel, Cebrián Antonio, Cánoves Joaquín, Martínez Alvaro, Mainar Luis, Porres Juan Carlos, Sanchis Juan, López Merino Vicente, Such Luis
Servicio de Cardiología del Hospital Clínico Universitario de Valencia. España.
Rev Esp Cardiol. 2002 Nov;55(11):1143-50. doi: 10.1016/s0300-8932(02)76777-8.
The aim of this study was to analyze the effects of myocardial stretching on excitation frequencies, as determined by spectral analysis, during ventricular fibrillation.
In 12 isolated rabbit heart preparations, ventricular activation during ventricular fibrillation was recorded with multiple electrodes. Recordings were obtained before, during and after ventricular dilatation produced with an intraventricular balloon. The dominant frequency of the signals obtained with each of the electrodes was determined by spectral analysis.
During the control phase, the mean, minimum and maximum dominant frequencies were, respectively, 14.3 1.7, 12.5 1.7, and 16.2 1.4 Hz, and the average difference between the maximum and minimum frequencies was 3.6 2.1 Hz. This difference was over 4 Hz in four cases, and in no case did it exceed 8 Hz. During ventricular stretching, the mean dominant frequency increased significantly (21.1 6.1 Hz; p < 0.0001), as did the minimum values (14 2.6 Hz; p < 0.05) and especially the maximum values (26.6 7.7 Hz; p < 0.0001). The difference between the maximum and minimum frequencies (12.6 6.4 Hz; p < 0.001) was over 4 Hz in all cases except one, and over 8 Hz in 9 cases. The maximum values were distributed heterogeneously during ventricular stretching. Upon suppressing ventricular stretching, the dominant frequency did not differ from controls.
Myocardial frequency maps during ventricular fibrillation show limited variations in the dominant frequency of the signals recorded in the lateral wall of the left ventricle. During stretching, the patterns were heterogeneous, due mainly to the marked increase in the maximum dominant frequency. In the experimental model used, the effects of stretching remitted after suppressing ventricular dilatation.
本研究旨在分析心肌拉伸对心室颤动期间通过频谱分析测定的激动频率的影响。
在12个离体兔心标本中，用多个电极记录心室颤动期间的心室激动。在心室球囊扩张前后及扩张过程中进行记录。通过频谱分析确定每个电极获得信号的主导频率。
在对照阶段，平均、最小和最大主导频率分别为14.3±1.7Hz、12.5±1.7Hz和16.2±1.4Hz，最大频率与最小频率的平均差值为3.6±2.1Hz。4例差值超过4Hz，无一例超过8Hz。在心室拉伸期间，平均主导频率显著增加（21.1±6.1Hz；p<0.0001），最小值（14±2.6Hz；p<0.05）尤其是最大值（26.6±7.7Hz；p<0.0001）也显著增加。除1例外在所有情况下最大频率与最小频率的差值（12.6±6.4Hz；p<0.001）均超过4Hz，9例超过8Hz。心室拉伸期间最大值分布不均一。抑制心室拉伸后，主导频率与对照无差异。
心室颤动期间的心肌频率图显示左心室侧壁记录信号的主导频率变化有限。拉伸期间，模式不均一，主要是由于最大主导频率显著增加。在所用实验模型中，抑制心室扩张后拉伸效应消失。
