Yamashita T, Murakawa Y, Sezaki K, Inoue M, Hayami N, Shuzui Y, Omata M
The Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Circulation. 1997 Sep 2;96(5):1537-41. doi: 10.1161/01.cir.96.5.1537.
Circadian variation in the incidence of acute cardiovascular events is well known but has not been extensively investigated in paroxysmal atrial fibrillation, although the significance of this arrhythmia is growing in our society with the increasing number of aged people.
We detected 150 patients with paroxysmal atrial fibrillation in a drug-free state from among 25,500 consecutive Holter recordings. To determine whether the onset, maintenance, and termination of paroxysmal atrial fibrillation were random events, we analyzed the total recorded duration of arrhythmia and the incidence of and number of patients with the onset, maintenance, and termination of this arrhythmia as hourly data and as hourly probabilities. A prominent circadian rhythm of the total duration of atrial fibrillation, approximately 90% of which was well explained by a single cosinusoidal function, was detected with a nadir around 11 AM. Because the onset of the arrhythmia had little or no circadian rhythm, this finding was due to a diurnal pattern of maintenance and termination, both of which were well expressed by a double-harmonic density function. Maintenance showed a trough at 11 AM, and termination showed a peak at the same time, leading to the nonuniform duration of single episodes of atrial fibrillation throughout the 24-hour day.
Paroxysmal atrial fibrillation showed a unique circadian variation that differed from the well-known pattern for acute cardiovascular events, a point that should be kept in mind when antiarrhythmic therapy is evaluated. Identification of factors that regulate the circadian pattern of the maintenance and termination of paroxysmal atrial fibrillation may lead to better chronotherapy for preventing perpetuation of this arrhythmia.
急性心血管事件发生率的昼夜变化已为人熟知，但阵发性心房颤动方面尚未进行广泛研究，尽管随着老年人口数量的增加，这种心律失常在社会中的重要性日益凸显。
我们从连续25500份动态心电图记录中检测出150例处于无药状态的阵发性心房颤动患者。为确定阵发性心房颤动的发作、持续和终止是否为随机事件，我们将心律失常的总记录时长以及该心律失常发作、持续和终止的发生率及患者数量作为每小时数据和每小时概率进行分析。检测到心房颤动总时长存在显著的昼夜节律，其中约90%可用单一余弦函数很好地解释，最低点出现在上午11点左右。由于心律失常的发作几乎没有昼夜节律，这一发现归因于持续和终止的昼夜模式，二者均可用双谐波密度函数很好地表示。持续在上午11点出现低谷，终止在同一时间出现高峰，导致心房颤动单次发作在24小时内的时长不均一。
阵发性心房颤动呈现出独特的昼夜变化，与急性心血管事件的知名模式不同，在评估抗心律失常治疗时应牢记这一点。识别调节阵发性心房颤动持续和终止昼夜模式的因素可能会带来更好的时间治疗方法，以预防这种心律失常的持续发作。
