| In the diagnostic procedure for coronary artery disease, electrocardiogram and dynamic electrocardiogram were applicationed generally. But they were limited diagnostic value for cardiovascular disease, because they could not reflect heart muscle ischemia in the earlier period. A part of coronary artery disease showed off false positive or false negative in electrocardiogram. The reasons of this were ectrocardiogram and dynamic electrocardiogram were in time domain fact of heart electric activity. But the electrocardiogram was nonlinear. Electric activity of heart was multi-domain and degenerative. So they needed a kind of research method that was non-linear and multi- domain .The method of study frequency domain was multi- domain and nonlinear. It could reflect electric activity of heart better. These was manifested electrocardio frequency spectrum had conclusive diagnostic value for independence nervousness function~[1,3,7] and had some diagnostic value in myocardial ischemia also. But different peak amplitude in electrocardio-spectral could reflex different nervous function. So somebody thought the changes of electrocardio-spectral in ischemia were successesd the different of nervous function. There had a lot of dispute in this question. Our studies approached the relation spectral domain of and electric activity withthe method of milt-domain.Objectives: (l)To establish a relatively novel scrutiny with short-time real time cardiac signals analysis in frequency domain and investigate the effects of ischemia to cardiac spectrum. (2) To discuss the clinical value of RR interval shot-time cardiac spectrum in predicting diagnosis and estimating therapeutic effect ischemia heart disease.Methods: (1) We completed this study by the means of spectral analysis with short-time cardiac signals. Power spectral analysis method 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) Control studies the different in earlier period and severity affection. (3) Recorded patients cardiac signals before and after percutaneous Tran luminal coronary angioplasty (PTCA) to observe the influence of coronary blood to cardiac power spectral analysis. (4)Reviewed the frequency spectrum characteristic in health adult, primary hypertension and myocardial ischemia of coronary artery heart disease.Results:(l) In clinical research, the group of normal ECG was 58.76+ 5.55nu in LF composition .The group of normal ECG was 49.06±6.13nu in LF component. (2) LF component in the earlier period group, the severity affection group and normal group were respectively 65.45 + 6.38 nu, 59.76± 7.57 nu and 49.06 + 6.13 nu, there were different in different group. HF component in the earlier period group, severity affection group and normalgroup were respectively 14.15+7.45 nu, 27.52+6.73 nu and 30.5 + 5.64 nu respectively. LF of RR in the earlier period and severity affection group were more than that in the normal group(p<0.05). HF component in the earlier period and the severity affection were smaller than that in the normal group (p<0.05). (3) After PTCA was applied, LF component of RR in serious CHD group decreased observably, it from 68.51+2.96 nu to 46.88+3.77 nu and HF component increased observably, it from 10.49+4.56 nu to 21.31 + 3.77 nu. (4 ) LF power was found more predominant in the essential hypertension than that in the normal group. That were 118.17+8.96 nu and 49.06+6.13 nu respectively. LF/HF had more predominant, that was 3.92+1.41 (p<0.01. But HF had no changes obviously, that were 30.56+5.64nu and 31.78+7.93 nu.Conclusions: (l)In clinical study, the group of no manifest changes in electrocardiogram was found more predominant than the normal group in LF component and HF component decreased significantly ( p<0.05 ) .LF component increased significantly and HF component had no change in EH group. (2) Obvious changing had taked place in RR interval frequency spectrum component in heart muscle ischemia group. There had manifest desperation in electrocardio frequency spectrum. The changes aggravated with ischemia of coronary artery. The group of severity affection in HF component was decrease and LF component was increase than the group of early affection in corona arteries. (p<0.05 ). (3) After PTCA the frequency spectrum both LF and HF were changed. LF component from 66.51+ 2.96nu to 46.95+ 3.77nu( p<0.01) , HF component from 10.49 + 4.56 nu to 21.315 ±5.12nu ( p<0.01). Variabilities of that were 25.01 %and 103.14% respectively. The changes of frequency spectrum component had correlated intimately with corona arteries blood. (4) The changes of electrocardio-frequency spectrum composition in the essential hypertension group showed that neural regulation had changed in the early time of essential hypertension.Concludly, the changes of electrocardio-frequency spectrum component could mirror heart muscle ischemia. The variance earlier before than the appearance of ischemia in ECG. It could supplementary ECG insufficiency for diagnosis heart muscle ischemia. So this method would become a kind of diagnostic method for heart muscle ischemia in the future.
|
PDF Full Text Request