Pediatric Department, Section of Pediatric Cardiology, Skane University Hospital, Lund University, Lund, Sweden.
BMC Cardiovasc Disord. 2013 Sep 10;13:67. doi: 10.1186/1471-2261-13-67.
In adults, impaired myocardial repolarization and increased risk of arrhythmia are known consequences of open heart surgery. Little is known, however, about post-operative consequences of cardiopulmonary bypass surgery in children. The aim of this study was to assess ventricular repolarization and coronary perfusion after bypass surgery for atrial septal defect (ASD) repair in children.
Twelve patients with ASD were assessed one day before and 5-6 days after ASD repair. Myocardial repolarization (corrected QT interval, QTc, QT dispersion, QTd, and PQ interval) was determined on 12-lead electrocardiograms. Coronary flow in proximal left anterior descending artery (peak flow velocity in diastole, PFVd) was assessed by transthoracic Doppler echocardiography.
Ten of the 12 (83%) children had normal myocardial repolarization before and after surgery. After surgery, QTc increased 1-9% in 5 (42%) patients, decreased 2-11% in 5 (42%) patients and did not change in 2 (16%) patients. Post-op QTc positively correlated with bypass time (R=0.686, p=0.014) and changes in PFVd (R=0.741, p=0.006). After surgery, QTd increased 33-67% in 4 (33%) patients, decreased 25-50% in 6 patients (50%) and did not change in 2 (16%) patients. After surgery, PQ interval increased 5-30% in 4 (33%) patients, decreased 4-29% in 6 (50%) patients and did not change in 1 (8%) patient. Post-op PQ positively correlated with bypass time (R=0.636, p=0.027). As previously reported, PFVd significantly increased after surgery (p<0.001).
Changes in QTc, PQ and PFVd are common in young children undergoing surgery for ASD repair. Post-op QTc significantly correlates with bypass time, suggesting prolonged cardiopulmonary bypass may impair ventricular repolarization. Post-op QTc significantly correlates with PFVd changes, suggesting increased coronary flow may also impair ventricular repolarization. The clinical significance and reversibility of these alternations require further investigations.
在成年人中，已知心脏直视手术后会出现心肌复极异常和心律失常风险增加。然而，关于儿童体外循环手术后的后果知之甚少。本研究旨在评估房间隔缺损（ASD）修复术后儿童的心室复极和冠状动脉灌注。
12 例 ASD 患儿分别于术前 1 天和术后 5-6 天进行评估。12 导联心电图测定心肌复极（校正 QT 间期，QTc，QT 离散度，QTd 和 PQ 间期）。经胸超声心动图测定左前降支近段冠状动脉血流（舒张期峰值血流速度，PFVd）。
12 例患儿中有 10 例（83%）术前和术后心肌复极正常。术后 5 例（42%）患者 QTc 增加 1-9%，5 例（42%）患者 QTc 减少 2-11%，2 例（16%）患者 QTc 不变。术后 QTc 与体外循环时间呈正相关（R=0.686，p=0.014），与 PFVd 变化呈正相关（R=0.741，p=0.006）。术后 4 例（33%）患者 QTd 增加 33-67%，6 例（50%）患者 QTd 减少 25-50%，2 例（16%）患者 QTd 不变。术后 4 例（33%）患者 PQ 间期增加 5-30%，6 例（50%）患者 PQ 间期减少 4-29%，1 例（8%）患者 PQ 间期不变。术后 PQ 与体外循环时间呈正相关（R=0.636，p=0.027）。如前所述，PFVd 术后明显增加（p<0.001）。
接受 ASD 修复术的年轻儿童中，QTc、PQ 和 PFVd 的变化很常见。术后 QTc 与体外循环时间显著相关，提示体外循环时间延长可能损害心室复极。术后 QTc 与 PFVd 变化显著相关，提示冠状动脉血流增加也可能损害心室复极。这些改变的临床意义和可逆性需要进一步研究。
