Cai N S, Dohnal M, Olsson S B
Department of Medicine I, Sahlgrenska Hospital, Gothenberg, Sweden.
Cardiovasc Res. 1987 Jun;21(6):455-62. doi: 10.1093/cvr/21.6.455.
A new computer assisted method for analysing RR interval histograms was devised in 32 patients with sustained atrial fibrillation. Twenty four hour ECG recordings were divided consecutively into periods with 64 heart beats and mean heart rates calculated for each period. Using increments of 10 beats.min-1 serial heart rate stratified histograms with 5120 RR intervals were constructed according to the calculated heart rate. In all histograms the RR intervals were sorted into 20 ms wide subgroups between 180 and 2100 ms. The analysis showed a bimodal RR distribution in 26 patients. Several indices were chosen to characterise a given RR interval peak in the histogram analysis. The rate dependence of peak was calculated for each individual peak. In the presence of two or more peaks a peak dominance change value was defined. Furthermore, differences and ratios between peak values at peak dominance change value (peak gap and peak value ratio) were calculated. A contour index was used to describe the smoothness of the appearance of the histogram. Comparisons were made between the histograms with periods composed of different numbers of heart beats (8, 16, 32, 64) for the mean heart rate calculation and between the histograms constructed with different numbers of RR intervals (512, 1024, 2560, 5120, 10,240, pooled data) in six patients. A significant finding was that greater than 5000 RR intervals should be used for the construction of a heart rate stratified histogram. Comparison was also made between the repeated histograms with a mean time interval of 137 days (7-413 days) in eight patients. The findings showed a high reproducibility of the heart rate stratified histogram.
为32例持续性心房颤动患者设计了一种新的计算机辅助RR间期直方图分析方法。将24小时心电图记录连续划分为包含64次心跳的时段，并计算每个时段的平均心率。根据计算出的心率，以10次·分钟⁻¹的增量构建包含5120个RR间期的系列心率分层直方图。在所有直方图中，RR间期被分类为180至2100毫秒之间宽度为20毫秒的亚组。分析显示26例患者的RR分布呈双峰型。在直方图分析中选择了几个指标来表征给定的RR间期峰值。计算每个单独峰值的峰值速率依赖性。在存在两个或更多峰值的情况下，定义了峰值优势变化值。此外，计算了峰值优势变化值时峰值之间的差异和比率（峰值间隙和峰值比率）。使用轮廓指数来描述直方图外观的平滑度。对用于计算平均心率的由不同心跳次数（8、16、32、64）组成的时段的直方图之间以及对6例患者中用不同RR间期数量（512、1024、2560、5120、10240，汇总数据）构建的直方图之间进行了比较。一个重要发现是，构建心率分层直方图应使用超过5000个RR间期。还对8例患者中平均时间间隔为137天（7 - 413天）的重复直方图进行了比较。结果表明心率分层直方图具有高度可重复性。
