单次血液透析中QT间期离散度的变化及其影响因素

目的 :研究维持性血液透析 (MHD)患者QT间期离散度 (QTd)的变化以及透析相关因素对其的影响。方法 :49例MHD患者分别于透析前静卧 15min及透析后立即记录 12导联同步心电图 ,计算QTd值 ,同时采取外周血测定生化指标 ,记录超滤脱水量、超滤率及血压等生理指标。结果 :MHD患者透析前QTd明显高于正常对照组 (P <0 .0 0 1) ,透析后QTd进一步增高 (P <0 .0 0 1) ;回归分析表明 ,透析后QTd增幅与透后HCO3 -的增高及透析脱水量呈正相关 (分别为r =0 .5 3 ,P <0 .0 0 1;r =0 .5 6,P <0 .0 0 1) ;合并高血压及心室肥厚组QTd分别显著高于非高血压及非心室肥厚组 (分别为P <0 .0 5、P <0 .0 1)。结论 :MHD患者QTd增高 ,透析使QTd进一步增高 ,其发生机制与透析脱水及快速纠正酸中毒有关。

Changes of the QT interval dispersion in the electrocardiogram and associated factors during single hemodialysis session

Objective To determine whether changes occur in the QT interval dispersion (QTd) in maintenance hemodialysis patients (MHD) and to assess the effect of hemodialysis on QTd. Methods Serial 12-lead electrocardiogram (ECG) recordings were carried out in 49 MHD patients starting just before a routine dialysis session and ending after dialysis immediately. Plasma electrolyte concentrations, bicarbonate, plasma creatinine, blood pressure, ultrafiltration volume and body weight were assessed before and after each hemodialysis session. Results In MHD patients, QTd was higher than that in control. After the hemodialysis session, we found a significant increase (P<0.001) in QTd and a significant increase in plasma bicarbonate concentration (P<0.001). A correlation was observed between the increase of QTd and the increase of plasma bicarbonate, ultrafiltration volume respectively (r=0.53,P<0.001;r=0.56,P<0.001, respectively). In hypertension subgroup and left ventricular hypertrophy subgroup, QTd was higher than that in patients without hypertension and left ventricular hypertrophy (P<0.05;P<0.01, respectively). Conclusions QTd is significantly increased in MHD patients compared with that in control subjects. Hemodialysis can increase the QTd in patients with terminal-stage renal failure and these changes may be attributed to ultrafiltration and increase of plasma bicarbonate during hemodialysis session.