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

1)高频QRS电位与小儿心脏手术心脏停搏后围术期心肌损伤：14例患儿心内直视手术期间记录到平均信号的心电图。心脏停搏后再灌流早期高频QRS电位下降，然后恢复到缺血前水平。高频QRS波群恢复时间与停搏时间及术后CK-MB值显著相关。结果提示，高频QRS波与心功能的变化可作为评价小儿心脏手术中心肌损伤的指标。低通气量的影响：研究低通气量对大鼠高频QRS电位(RMS)和压力-容量关系的影响。EMAX、PRSW和RMS在低通气期降低，在正常通气期回升。%RMS与%PRSW有较好的相关性。结果表明，心功能的下降可以通过RMS的变化来评估。3)高频QRS电位和心功能的变化。朗宁多夫灌流大鼠离体心：观察大鼠离体心缺血再灌注期高频QRS波及心功能的变化。停跳后再灌流早期，左心室dp/dt、心率、心率-压力乘积和RMS均下降，然后恢复至缺血前水平。结果提示，心肌缺血再灌注期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.