VENTRICULAR PRESSURE AREA LOOP CHARACTERISTICS IN THE STAGE-16 TO STAGE-24 CHICK-EMBRYO
VENTRICULAR PRESSURE AREA LOOP CHARACTERISTICS IN THE STAGE-16 TO STAGE-24 CHICK-EMBRYO
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DOI：
10.1161/01.res.68.1.226
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发表时间：
1991-01-01
影响因子：
20.1
通讯作者：
CLARK, EB
中科院分区：
文献类型：
--
作者：
KELLER, BB;HU, N;CLARK, EB
胚胎心血管功能的准确描述需要标准的测量技术，以适应发展中的心脏的小尺度。 在成熟的心脏中，心室压力和容积的分析准确地定义了功能。 由于在胚胎心脏中的体积的体内测量是不可行的，我们测试的假设，心室压力面积环准确地定义心室功能的阶段16至阶段24白色来航鸡胚胎。 我们同时测量心室压力与伺服零位压力系统，并记录在60 Hz的视频图像。 将压力波形真实的叠加到视频图像上。 平面测量视频场的心外膜心室横截面积和心室压力。 使用快速傅立叶变换滤波器平滑压力和面积数据并绘图。 数据报告为平均值+/-SEM，n大于或等于4，并通过回归分析和方差分析进行检验（p < 0.05）。 心率从第16阶段的90+/-7次/分增加到第24阶段的130+/-13次/分。 所有压力-面积环均表现为舒张期充盈、等长收缩、射血和等长舒张，与成熟心脏的压力-容积环相似。 等长收缩时间从42+/-5增加到62+/-4毫秒（p < 0.05），而等长舒张时间在第16和24阶段之间分别为124+/-12和120+/-10毫秒（p > 0.05）。 最大瞬时心室压与面积比值比峰值心室压或最小心室面积更能识别收缩末期。 因此，压力-面积关系定义了鸡胚心脏的心室功能。
The accurate description of embryonic cardiovascular function requires the adaption of standard measurement techniques to the small scale of the developing heart. In the mature heart, the analysis of ventricular pressure and volume accurately defines function. Because in vivo measures of volume are not feasible in the embryonic heart, we tested the hypothesis that ventricular pressure-area loops accurately define ventricular function in the stage 16 to stage 24 white Leghorn chick embryo. We simultaneously measured ventricular pressure with a servo-null pressure system and recorded video images at 60 Hz. The pressure waveform was superimposed onto the video image in real time. Video fields were planimetered for epicardial ventricular cross-sectional area and ventricular pressure. Pressure and area data were smoothed using a fast Fourier transform filter and plotted. Data are reported as mean+/-SEM, n greater-than-or-equal-to 4, and were tested by regression analysis and analysis of variance (p < 0.05). Heart rate increased from 90+/-7 beats/min at stage 16 to 130+/-13 beats/min at stage 24. All pressure-area loops displayed diastolic filling, isometric contraction, ejection, and isometric relaxation, similar to pressure-volume loops of the mature heart. Isometric contraction time increased from 42+/-5 to 62+/-4 msec (p < 0.05), while isometric relaxation time was 124+/-12 and 120+/-10 msec (p > 0.05) between stages 16 and 24, respectively. The maximum ratio of instantaneous ventricular pressure to area identified end systole better than peak ventricular pressure or minimum ventricular area. Thus, pressure-area relations define ventricular function in the embryonic chick heart.