Massin M M, Maeyns K, Withofs N, Gérard P
Division of Pediatric Cardiology, CHR Citadelle, University of Liège, Belgium.
Cardiology. 2000;93(1-2):70-3. doi: 10.1159/000007004.
The aim of the present study was to identify and quantify the rate dependence of premature ventricular contractions (PVC) during childhood. A 24-hour Holter recording was performed in 16 consecutive children, aged 22 days to 11 years (mean age 5.6 years), with frequent (>5,000/day), isolated monomorphic PVC. Those PVC were identified and the length of the preceding sinus cycle was measured. The values were ordered into 50-ms class intervals, and the percentage of PVC for each class was calculated and then analyzed by linear regression analysis. On the basis of the significance of the p value, and the positive or negative value of the slope, we identified a tachycardia-enhanced, a bradycardia-enhanced, and an indifferent pattern. Chronobiologic analysis was made by the cosinor method. All the patients had upper and lower limits of cycle length beyond which PVC disappeared. A tachycardia-enhanced pattern was present in 7 patients and an indifferent one in 9 patients. In the latter a second-degree polynomial correlation was systematically found. Children but not infants had a significant circadian variation in the frequency of PVC with a very variable time of highest incidence. In conclusion, it is possible to identify a circadian rhythm of PVC and a spontaneous trend between their incidence and the length of the preceding cardiac cycle in children.
本研究的目的是确定并量化儿童期室性早搏（PVC）的频率依赖性。对16名年龄在22天至11岁（平均年龄5.6岁）、频发（>5000次/天）、孤立性单形性PVC的连续儿童进行了24小时动态心电图记录。识别出这些PVC，并测量其前窦性周期的长度。将这些值按50毫秒的组距进行排序，计算每组PVC的百分比，然后通过线性回归分析进行分析。根据p值的显著性以及斜率的正负值，我们确定了心动过速增强型、心动过缓增强型和无差异型模式。采用余弦法进行时间生物学分析。所有患者的周期长度均有上限和下限，超过此范围PVC消失。7例患者呈现心动过速增强型模式，9例患者呈现无差异型模式。在后者中，系统地发现了二次多项式相关性。儿童而非婴儿的PVC频率存在显著的昼夜变化，最高发生率的时间变化很大。总之，在儿童中可以确定PVC的昼夜节律以及其发生率与前一心搏周期长度之间的自发趋势。
