选择性冠状动脉造影评价常规心电图ST-T改变在冠心病中的诊断价值

目的:评价常规心电图检查中ST-T改变在冠心病诊断中的价值。方法:以选择性冠状动脉造影为对照,研究连续194例病人临床症状及心电图ST-T改变与造影结果的关系。结果:造影发现136例病人有明显的冠状动脉狭窄性病变,58例未发现明显病变。非典型心脏症状的病人无论是否有ST-T的异常,冠状动脉造影的阳性率仅4%～14％,而典型症状伴有ST-T异常的病人阳性率较高(89.4％)。结论:ST-T异常伴有典型心脏症状的诊断冠状动脉病变的可靠指标。     

顽固性室性早搏的射频消融治疗

目的 :通过对 2 3例顽固性室性早搏 (简称室早 )的射频消融分析 ,探讨室早的心电图特点、消融方法及效果 .方法 :男性 16例 ,女性 7例 ,均为频发、药物难治、症状明显的顽固性单形性室早患者 ,年龄(4 4 4± 9 6 )岁 .采用起搏标测和激动顺序标测 ,前者以起搏时与室早QRS波形态完全相同点为消融靶点 ,后者以早搏时最早心室激动点为消融靶点 .2 3例中 17例室早起源于右室 ,4例起源于左室 .消融即刻成功率86 9% ,累积放电 (930 4± 72 5 )s,成功者行动态心电图检查记录消融前后室早数为 (5 6 71± 2 4 36 )次 / 2 4h和 (39± 5 2 )次 / 2 4h (P <0 0 1) .随访 (2 3 2± 12 3)月 ,未服任何抗心律失常药 ,无 1例复发及并发症发生 .结论 :射频消融可有效而安全地消除单形性室早 ,采用粗标激动顺序、精标起搏图形 ,多点、长时间、高功率放电可提高成功率 ,降低复发率 ,可作为症状严重、药物无效或不能耐受患者的治疗选择     

血压变异与心率变异及心电异常相关性分析

目的：研究血压变异(BPV)与心率变异(HRV)及心电图(ECG)异常相关性，方法：对157例未经治疗的早期高血压患者及167例未服过影响血压及心率药物的正常人，进行BPV、HRV及ECG异常的相关分析，各种数据在同一时刻得到，结果：当血压昼夜节律消失(非杓型)，BPV及HRV不正常，ECG异常明显高于其他组，当高血压患者血压昼夜节律存在时HRV各项指标接近正常，ECG异常率较低，HRV降低与血压负荷升高呈明显正相关，与心电异常也呈明显正相关，结论：对高血压治疗的目的。不仅仅是降压，还应尽量恢复昼夜血压的规律性，降低夜间血压负荷，调节植物神经功能，对于血压正常的患者。血压昼夜节律消失也应投以关照给予植物神经功能调节，达到或降低靶器官损伤或延缓靶器官损害的目的，提高患者的生活质量。     

Effects of gender,age, and heart rate on QT intervals in children

The objective of this study was to determine if gender, age, and heart rate affect corrected QT intervals in children. Electrocardiograms were obtained from 781 healthy children 10–18 years of age. Corrected QT intervals were significantly (p < 0.0005) greater for girls than for boys in the entire population and for each age group over 14 years. The corrected QT interval varied inversely with age and directly with heart rate. Hence gender, age, and heart rate should be considered when diagnosing long QT syndrome.     

A Field-Compatible Method for Interpolating Biopotentials

Mapping of bioelectric potentials over a given surface (e.g., the torso surface, the scalp) often requires interpolation of potentials into regions of missing data. Existing interpolation methods introduce significant errors when interpolating into large regions of high potential gradients, due mostly to their incompatibility with the properties of the three-dimensional (3D) potential field. In this paper, an interpolation method, inverse-forward (IF) interpolation, was developed to be consistent with Laplace's equation that governs the 3D field in the volume conductor bounded by the mapped surface. This method is evaluated in an experimental heart–torso preparation in the context of electrocardiographic body surface potential mapping. Results demonstrate that IF interpolation is able to recreate major potential features such as a potential minimum and high potential gradients within a large region of missing data. Other commonly used interpolation methods failed to reconstruct major potential features or preserve high potential gradients. An example of IF interpolation with patient data is provided to illustrate its applicability in the actual clinical setting. Application of IF interpolation in the context of noninvasive reconstruction of epicardial potentials (the inverse problem) is also examined. © 1998 Biomedical Engineering Society. PAC98: 8710+e, 0260Ed     

长序列心电信号最佳复杂度的确定

研究了长序列心电信号的最佳复杂度。先将原始序列符号化 ,再采用 L empel- Ziv算法来计算复杂度 ,探讨影响复杂度的各种因素 ,然后对三组不同信号即正常心电、心绞痛和心肌梗塞信号进行分析。结果表明 ,采用最佳阈值比用平均值为阈值得到的复杂度更能明显地分辨出正常和异常信号 ,原始序列符号化的阈值以及信号长度直接影响序列复杂度 ,因此 ,在实际信号的复杂度测量上 ,应采用最佳阈值和最佳信号长度。     

Filter properties of root mean square successive difference (RMSSD) for heart rate

The root mean square successive difference (RMSSD) in heart period series is a time domain measure of heart period variability. The RMSSD is sensitive to high-frequency heart period fluctuations in the respiratory frequency range and has been used as an index of vagal cardiac control. By transfer function simulations, the RMSSD statistic is shown to represent a high-pass filter that effectively captures respiratory sinus arrhythmia but also passes lower frequency fluctuations that can include sympathetic influences. These simulations, together with analysis of actual heart period series, reveal that the RMSSD is biased by basal heart period. Although between-subjects levels of RMSSD covary highly with spectral estimates of high-frequency variability, within-subject RMSSD change scores account for only 50-60% of the variance in spectral estimates. The present findings raise caveats in the applications and interpretation of the RMSSD statistic.     

Evaluation of telephone transmission for computer electrocardiographic interpretation in Japan

The reliability of the Japanese public telephone facilities to transmit electrocardiograms (e.c.g.) for computer interpretation was assessed. The International Business Machine's (IBM) e.c.g. computer program by Bonner was used. No appreciable distortion of e.c.g. was observed following repeated transmission from hospitals separated by 1000 km. Thirty-four normal and 66 abnormal e.c.g.s. were transmitted twice. Identical results were observed in 97% of normals and 92% of abnormals. Following these fundamental experiments, 1236 patients' e.c.g.s. were transmitted for computer intepretation. The study showed that 98·6% (1219 cases) were technically satisfactory and 1·4% (17 cases) were not. The 17 unsatisfactory cases were classified into ten unreceivable data formats, six inconsistent measurements and one unacceptable noise level. The authors concluded that the Japanese public telephone facilities were acceptable for the transmission of e.c.g.s. for computer interpretation.     

Delineation of the QRS complex using the envelope of the e.c.g.

A new algorithm for QRS delineation has been developed. Based on the envelope of the e.c.g. signal a delineation function is defined, which yields a single positive pulse for each complex. From this function the onset and end of the QRS or, alternatively, a fiducial point is determined. To remove low-frequency component such as S-T abnormalities without distortion of the QRS complex, a filter with time-varying characteristics is used. The accuracy of the method has been evaluated in a test set of different QRS complexes obtained from coronary care patients. For QRS onset, the standard deviation of the difference between automated and manual determination was 7 ms in normal beats and 14 ms in ectopic beats. With simulated noise added to each waveform an average dispersion of 7 ms was observed in the recognition of the QRS onset at a signal-to-noise ratio of 15 dB. The corresponding dispersion in the location of a fiducial point was 2 ms. Using simulated e.c.g. data, the stability of the method is demonstrated for transitions between different waveform morphologies. Presented in part at ‘Computers in cardiology’, Florence, 23rd–25th September 1981     

CSS-Ⅱ型ECG微机自动诊断与临床金标准在1160例中的比较研究

作者自行设计的CSS-Ⅱ型心电图微型计算机自动诊断系统试用于临床,受试者1160例,其中波形异常和心律失常共247份心电图,从913份正常心电图中随机抽样106份,两者共计353份图纸,用本研究诊断确定的“金标准”(Gold standard)与该系统的自动诊断结论进行比较。结果:波形诊断及心律失常的诊断一致率均在90％以上,排除了机遇诊断一致率,其波形为90％,心律失常为88％。