| Electrocardiogram is useful in detecting cardiac disease, but it's value is limited when it is analysed in real time domain. Recently, power spectral analysis of cardiac real time signals has been shown to be a prospective predictor of cardiac mortality and arrhythmias. Many study has also proved that the spectra of patients with coronary heart disease was differ from that of normal, but it's reason hasn't been clare by now. Here we discussed effects of coronary artery blood to cardiac spectra and the potential clinical application of short-time power spectral analysis in detecting coronary heart disease.Objective: (DTo establish a relatively novel scrutiny with short-time real time cardiac signals analysised in frequenty domain and investigate the effects of ischemia to cardiac spectra. (2) To discuss the clinical value of RR ^ PR interval shot-time cardiac spectra in detecting ischemia heart disease.Methods: (1) we completed this study by the means of spectral analysis with short-time cardiac signals. AA interval and AV interval were measured on His bundle electrogram in denervated cats by a template-matched algorithm automatically. Power spectral analysis was performed by fast Fourier transform (FFT) and the power of high-frequency (HF 0.15-0.4Hz), low-frequency (LF 0.04-0.15Hz) were expressed in normalized unites (nu). (2) Spectral analysis of patients with coronary disease confirmed by coronary arteriongraphy was studied in separate classes. Meanwhile, transesophageal atrial pacing (TEAP) were performed in normal patients to observe their corresponding changes in cardiac spectra, and quantitied ischemic effects to cardiac spectra. (3) Recorded patients cardiac signals before and after percutaneous trandluminal coronary angioplasty(PTCA) to observe the influence of coronary blood to cardiac power spectral analysis.Results: (1) HF power was found more predominant in denervated cat, but LF power was very smaller. Spectra of AA and AV were similar with each other.(2) Our investigation demonstrated that the change of heart rate played a important role in determining the pattern of cardiac power spectra. HFcomponent of AV decreased from 85.4+6.2nu to 34.7+11.4nu (p<0.05) and LF component increased from 8.1+2.7nu to 47.2+4.4nu (p<0.05) when pacing cycle length decreased from 400ms to 250ms. And when coronary artery occluded, HF component of AV decreased from 65.2+12.3nu to 25.8+10.5nu (p<0.05) and LF component increased from 20.9+8.4nu to 63.4+10.1nu (p<0.05) when pacing cycle length decreased from 400ms to 250ms.(3) LF component increased and HF component decreased when right artery was occluded. LF component of AA increased from 8.2+3.2nu to 23.0+18.9nu (p<0.05) and that of AV increased from 16.4+10.0nu to 31.0+11.3nu (p<0.05). HF component of AA decreased from 80.0+7.1nu to 59.4+23.9nu (p<0.05) and that of AV decreased from 72.1+11.6nu to 54.4+13.4nu (p<0.05). LF component of AA^ AV increased 126.8% ^ 103% , and HF component of AAs AV decreased 14.8%> 15.2% when heart rate effect was corrected.(4) In clinical study, LF component of RR in normaK angina pectoris group ^ myocardial infarction group were respectively 31.96+8.43nu > 43.04+5.57nu> 57.59+11.45nu, and HF component of that were respectively 6S.04+8.43mis 56.96+5.57nu > 42.41+11.45nu. LF component of RR in myocardial infarction group was more than angina pectoris group (p<0.05), and that in angina pectoris group was more than in normal (p<0.05). HF component of RR in myocardial infarction group was smaller than angina pectoris group (p<0.05), and that in angina pectoris group was smaller than in normal (p<0.05). LF component of PR in normaK angina pectoris grcn^ myocardial infarction group were respectively 28.84+5.19nu H 39.63+6.51nu> 40.82+11.29nu, and HF component of that were respectively 71.16+5.19nu, 60.37+6.51nu> 59.18+11.29nu. LF of PR in myocardial infarction group and angina pectoris group were more than normal (p<0.05). HF component of PR in myocardial infarction group and angina pect... |
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