Stafford P J, Robinson D, Vincent R
Cardiac Department, Royal Sussex County Hospital, Brighton and Trafford Centre for Medical Research, University of Sussex, Falmer.
Br Heart J. 1995 Oct;74(4):413-8. doi: 10.1136/hrt.74.4.413.
To define the ability of analysis of the signal averaged P wave to identify patients with paroxysmal atrial fibrillation (AF) and establish whether differences in quantitative variables between patients and controls are due to concurrent cardiopulmonary disease, greater atrial dimension, or to unrelated changes in atrial electrophysiology.
An observational parallel group study.
Cardiac department of a busy district general hospital.
58 participants without cardiopulmonary disease (24 with paroxysmal AF and 34 controls, group A) and 57 with cardiac or respiratory conditions (31 with paroxysmal AF and 26 controls, group B). Mean (range) age of patients was 54 (25-71) and controls 53 (34-78) for group A and 65 (45-81) and 62 (36-78) respectively for group B. Left atrial size was similar in patients and controls in each group (mean (SEM)) group A: 2.39 (0.1) v 2.19 (0.07) cm; group B: 2.51 (0.10) v 2.71 (0.12) cm).
Analysis of the P wave after P-wave-specific signal averaging. Filtered P wave duration and spatial velocity were calculated. Energies contained in frequency bands from 20, 30, 40, 60, and 80 to 150 Hz after spectral analysis were expressed as absolute values (P20, P30 etc) and ratios of high to low frequency energy (PR20, PR30, etc).
Duration and peak spatial velocity were increased in patients with paroxysmal AF (median (interquartile range) duration group A: 144 (137-155) v 136 (129-143) ms, P = 0.007; group B: 155 (144-159) v 142 (136-151) ms, P = 0.002; peak spatial velocity group A: 16.5 (14.1-21.2) v 14.5 (11.7-18.1) mV/s, P = 0.02; group B: 18.9 (14.8-21.8) v 14.3 (12.6-17.6) mV/s, P = 0.01). Energy contained in frequency bands from 20, 30, 40, 60 and 80 to 150 Hz was expressed as absolute values (P20, P30, P40, P60, and P80) and percentage energy ratios. P30, P60, and P80 were significantly greater in patients with AF in group A (for example P60: 3.9 (3.0-5.3) v 3.1 (2.0-4.3) microV2.s, P = 0.02) and P20, P30, and P40 were increased in those with AF in group B (for example P40: 16.7 (9.9-20.8) v 10.8 (8.1-14.8) microV2.s, P = 0.02). A score developed from logistic regression analysis of duration and P60 identified patients with paroxysmal AF with a sensitivity of 81% and specificity of 73%.
Increased P wave duration and magnitude are associated with paroxysmal AF with and without additional cardiopulmonary disease. The discriminant ability of the signal averaged P wave is improved by analysis of duration and a magnitude variable. These results invite prospective assessment of the ability of the signal averaged P wave to predict paroxysmal AF in unselected patients.
确定信号平均P波分析识别阵发性心房颤动（AF）患者的能力，并确定患者与对照组之间定量变量的差异是由于并发心肺疾病、心房尺寸增大，还是由于心房电生理学的无关变化。
一项观察性平行组研究。
一家繁忙的地区综合医院的心脏科。
58名无心肺疾病的参与者（24名阵发性AF患者和34名对照组，A组）和57名患有心脏或呼吸疾病的患者（31名阵发性AF患者和26名对照组，B组）。A组患者的平均（范围）年龄为54（25 - 71）岁，对照组为53（34 - 78）岁；B组患者平均年龄为65（45 - 81）岁，对照组为62（36 - 78）岁。每组患者和对照组的左心房大小相似（平均（标准误））：A组：2.39（0.1）对2.19（0.07）cm；B组：2.51（0.10）对2.71（0.12）cm）。
在进行P波特异性信号平均后分析P波。计算滤波后的P波持续时间和空间速度。频谱分析后，20、30、40、60和80至150Hz频段内包含的能量以绝对值（P20、P30等）以及高频与低频能量之比（PR20、PR30等）表示。
阵发性AF患者的持续时间和峰值空间速度增加（中位数（四分位间距）持续时间：A组：144（137 - 155）对136（129 - 143）ms，P = 0.007；B组：155（144 - 159）对142（136 - 151）ms，P = 0.002；峰值空间速度：A组：16.5（14.1 - 21.2）对14.5（11.7 - 18.1）mV/s，P = 0.02；B组：18.9（14.8 - 21.8）对14.3（12.6 - 17.6）mV/s，P = 0.01）。20、30、40、60和80至150Hz频段内包含的能量以绝对值（P20、P30、P40、P60和P80）以及能量百分比比值表示。A组AF患者的P30、P60和P80显著更高（例如P60：3.9（3.0 - 5.3）对3.1（2.0 - 4.3）μV².s，P = 0.02），B组AF患者的P20、P30和P40增加（例如P40：16.7（9.9 - 20.8）对10.8（8.1 - 14.8）μV².s，P = 0.02）。根据持续时间和P60的逻辑回归分析得出的评分识别阵发性AF患者的敏感性为81%，特异性为73%。
P波持续时间和幅度增加与有无额外心肺疾病的阵发性AF相关。通过分析持续时间和一个幅度变量可提高信号平均P波的判别能力。这些结果促使对信号平均P波在未选择患者中预测阵发性AF的能力进行前瞻性评估。
