Yamada A, Hayano J, Sakata S, Okada A, Mukai S, Ohte N, Kimura G
Third Department of Internal Medicine, Nagoya City University Medical School, Nagoya, Japan.
Circulation. 2000 Jul 18;102(3):300-6. doi: 10.1161/01.cir.102.3.300.
BACKGROUND-Variations in the ventricular response interval (VRI) during atrial fibrillation (AF) may be reduced in patients with adverse clinical outcomes. The properties of VRI dynamics associated with prognosis remain undetermined. METHODS AND RESULTS-In 107 patients with chronic AF (age, 64+/-9 years), we analyzed a 24-hour ambulatory ECG for VRI variability (SD, SD of successive differences, and SD of 5-minute averages) and VRI irregularity (Shannon entropy of histogram, symbolic dynamics, and approximate entropy of beat-to-beat and minute-to-minute fluctuations [ApEn(b-b) and ApEn(m-m)]). During a follow-up period of 33+/-16 months, 18 patients died (17%), 9 from cardiac causes, 7 from fatal strokes, and 2 from malignancies. Reductions in all VRI variability and irregularity measures were associated with an increased risk for cardiac death but not for fatal stroke. A significant association with cardiac death was also found for ejection fraction (relative risk, 1.10; 95% confidence interval [CI], 1.04 to 1.17, per 1% decrement) and ischemic AF (relative risk, 6.52; 95% CI, 1.62 to 26. 3). After adjustment for these clinical variables, all irregularity measures except symbolic dynamics had predictive value (relative risks [95% CIs] per 1SD decrement: Shannon entropy of histogram, 2. 03 [1.14 to 3.61]; ApEn(b-b), 1.72 [1.14 to 2.60]; and ApEn(m-m), 1. 90 [1.03 to 3.52]); however, the predictive power of variability measures was no longer significant. When the patients were stratified with the 33rd and 67th percentile values of ApEn(b-b) (1. 83 and 1.94, respectively), the 5-year cardiac mortality rates for the upper, middle, and lower tertiles were 0%, 13%, and 43%, respectively (log-rank test, P=0.04). CONCLUSIONS-Reduced VRI irregularity in a 24-hour ambulatory ECG has an independent prognostic value for cardiac mortality during long-term follow-up in patients with chronic AF.
背景——房颤（AF）患者心室反应间期（VRI）的变异性在临床预后不良的患者中可能会降低。与预后相关的VRI动态特性仍未确定。方法与结果——在107例慢性AF患者（年龄64±9岁）中，我们分析了24小时动态心电图的VRI变异性（标准差、逐差标准差和5分钟平均值标准差）和VRI不规则性（直方图的香农熵、符号动力学以及逐搏和每分钟波动的近似熵[ApEn(b-b)和ApEn(m-m)]）。在33±16个月的随访期内，18例患者死亡（17%），9例死于心脏原因，7例死于致命性卒中，2例死于恶性肿瘤。所有VRI变异性和不规则性指标的降低都与心脏死亡风险增加相关，但与致命性卒中无关。射血分数（相对风险，1.10；95%置信区间[CI]，1.04至1.17，每降低1%）和缺血性AF（相对风险，6.52；95%CI，1.62至26.3）也与心脏死亡显著相关。在对这些临床变量进行校正后，除符号动力学外的所有不规则性指标都具有预测价值（每降低1个标准差的相对风险[95%CI]：直方图的香农熵，2.03[1.14至3.61]；ApEn(b-b)，1.72[1.14至2.60]；ApEn(m-m)，1.90[1.03至3.52]）；然而，变异性指标的预测能力不再显著。当根据ApEn(b-b)的第33和67百分位数（分别为1.83和1.94）对患者进行分层时，上、中、下三分位数的5年心脏死亡率分别为0%、13%和43%（对数秩检验，P=0.04）。结论——24小时动态心电图中VRI不规则性降低对慢性AF患者长期随访期间的心脏死亡率具有独立的预后价值。
