ESTIMATION OF PERIOPERATIVE CARDIAC FUNCTION FOLLOWING PEDIATRIC CARDIAC SURGERY USING NONINVASIVE MEASUREMENT OF HIGH FREQUENCY QRS POTENTIALS

本研究旨在利用高频QRS电位识别小儿心脏手术后术中心肌损伤和围术期心功能的新标志物。1)小儿心脏手术心脏骤停后的高频QRS电位与围术期心肌损伤：记录14例小儿心内直视手术时的平均信号心电图。高频QRS电位在心脏骤停后早期再灌注时下降，然后恢复到缺血前水平。高频QRS电位恢复时间与骤停时间及术后CK-MB值显著相关。结果提示，可以通过QRS复合体高频心电图信号的变化来评估小儿心脏手术心肌损伤。2)高频QRS电位与心功能。低通气的影响：观察大鼠低通气时高频QRS电位（RMS）的变化及压容积关系。Emax、PRSW和RMS在低通气时下降，在正常通气时恢复。%RMS与%PRSW有良好的相关性。3)高频QRS电位与心功能的关系。Langendorff灌流大鼠离体心脏：研究Langendorff灌流大鼠离体心脏缺血再灌注后高频QRS电位（RMS）和心功能的变化。左心室dp/dt、心率、率压积和RMS在心脏骤停后早期再灌注时下降，然后恢复到缺血前的水平。结果提示，缺血再灌注后心功能的恢复可通过RMS的变化来评价。

This study seeks to identify a new marker of intraoperative myocardial injury and perioperative cardiac function following pediatric cardiac surgery using high frequency QRS potentials.1) High frequency QRS potentials and perioperative myocardial injury following cardioplegic arrest in pediatric cardiac surgery : Signal-averaged electrocardiograms were recorded during open heart operation in 14 pediatric patients. The high frequency QRS potentials decreased at early reperfusion following cardioplegic arrest and then returned to preischemic levels. The recovery time of high frequency QRS potentials significantly correlated with arrest time and the post operative CK-MB values. The results suggest that myocardial injury in pediatric cardiac surgery can be assessed by changes in the high frequency ECG signals of the QRS complex.2) High frequency QRS potentials and the cardiac function. influence of hypoventilation : The changes in high frequency QRS potentials (RMS) and pressure volume relationship were studied in rat during hypoventilation. Emax, PRSW and RMS decreased during hypoventilation and returned during normal ventilation. There were good correlation between %RMS and %PRSW. The results suggest that decrease in cardiac function can be assessed by changes in RMS.3) High frequency QRS potentials and the cardiac function. isolated rat heart of Langendorff perfusion : The changes in high frequency QRS potentials (RMS) and cardiac function were studied in isolated rat heart of Langendorff perfusion during post ischemic reperfusion period. Left ventricular dp/dt, heart rate, rate-pressure-product and RMS decreased at early reperfusion following cardioplegic arrest and then returned to preischemic levels. The results suggest that the recovery of cardiac function after post ischemic reperfusion period can be assessed by changes in RMS.