Katircibasi M T, Deniz F, Pamukcu B, Binici S, Atar I
Etimesgut Military Hospital, Department of Cardiology, Ankara, Turkey.
Exp Clin Endocrinol Diabetes. 2007 Jun;115(6):376-9. doi: 10.1055/s-2007-971066.
P-wave duration is defined as the time measured from the onset to the offset of the P-wave in surface electrocardiogram (ECG). Prolonged P wave duration and increased P wave dispersion (PWD) have been reported to carry an increased risk for atrial fibrillation.
Our aim was to evaluate the role of hyperthyroidism on P wave duration and dispersion, to investigate the effect of anti-thyroid therapy on P wave duration and dispersion.
A total of 44 consecutive subjects (22 patients with newly diagnosed overt hyperthyroidism and 22 randomly selected euthyroid healthy subjects) were enrolled in the study. Transthoracic echocardiography, 12 lead surface ECG and thyroid hormone levels were studied at the time of enrollment, in the first and third months of the 6-8 mg/kg/day propylthiouracil therapy. Patients were followed-up for 3 months.
Patient and control groups were consisted of age and sex matched subjects. Baseline left atrial diameter was similar between the patient and control groups (3.4+/-0.3 cm and 3.4+/-0.3 cm respectively, p=0.813). The maximum P-wave duration (P maximum) was 113.1+/-6.6 and 105.7+/-4.1 ms in patient and control groups (p=0.001). PWD was 31.5+/-9.5 and 25.2+/-5.9 ms in patient and control groups respectively (p=0.015). At the third month of propylthiouracil treatment P maximum and PWD were decreased in the patient group at statistically significant level and returned back in normal limits (p<0.001 and p=0.001).
P wave duration and PWD are found prolonged in hyperthyroid patients and propylthiouracil treatment decreased them effectively. This mechanism may establish how the anti-thyroid treatment may prevent the development of atrial fibrillation in hyperthyroid patients.
P波时限定义为体表心电图（ECG）中从P波起始到结束所测量的时间。据报道，P波时限延长和P波离散度（PWD）增加会使房颤风险升高。
我们的目的是评估甲状腺功能亢进对P波时限和离散度的作用，研究抗甲状腺治疗对P波时限和离散度的影响。
本研究共纳入44例连续受试者（22例新诊断的显性甲状腺功能亢进患者和22例随机选取的甲状腺功能正常的健康受试者）。在入组时、接受6 - 8mg/kg/天丙硫氧嘧啶治疗的第1个月和第3个月，对受试者进行经胸超声心动图、12导联体表心电图及甲状腺激素水平检查。患者随访3个月。
患者组和对照组由年龄和性别匹配的受试者组成。患者组和对照组的基线左心房直径相似（分别为3.4±0.3cm和3.4±0.3cm，p = 0.813）。患者组和对照组的最大P波时限（P最大值）分别为113.1±6.6和105.7±4.1ms（p = 0.001）。患者组和对照组的PWD分别为31.5±9.5和25.2±5.9ms（p = 0.015）。在丙硫氧嘧啶治疗的第3个月，患者组的P最大值和PWD在统计学显著水平下降并恢复到正常范围（p < 0.001和p = 0.001）。
甲状腺功能亢进患者的P波时限和PWD延长，丙硫氧嘧啶治疗可有效降低它们。这一机制可能解释了抗甲状腺治疗如何预防甲状腺功能亢进患者房颤的发生。
