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OBJECTIVES@#Fourier transform infrared spectroscopy (FTIR) was used to analyze myocardial infarction tissues at different stages of pathological change to achieve the forensic pathology diagnosis of acute and old myocardial infarction.@*METHODS@#FTIR spectra data of early ischemic myocardium, necrotic myocardium, and myocardial fibrous tissue in the left ventricular anterior wall of the sudden death group of atherosclerotic heart disease and the myocardium of the normal control group were collected using hematoxylin-eosin (HE) and immunohistochemistry (IHC) staining as a reference, and the data were analyzed using multivariate statistical analysis.@*RESULTS@#The mean normalized spectra of control myocardium, early ischemic myocardium and necrotic myocardium were relatively similar, but the mean second derivative spectra were significantly different. The peak intensity of secondary structure of proteins in early ischemic myocardium was significantly higher than in other types of myocardium, and the peak intensity of the α-helix in necrotic myocardium was the lowest. The peaks of amide Ⅰ and amide Ⅱ in the mean normalized spectra of myocardial fibrous tissue significantly shifted towards higher wave numbers, the peak intensities of amide Ⅱ and amide Ⅲ were higher than those of other types of myocardium, and the peak intensities at 1 338, 1 284, 1 238 and 1 204 cm-1 in the mean second derivative spectra were significantly enhanced. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) showed that FTIR could distinguish different types of myocardium.@*CONCLUSIONS@#FTIR technique has the potential to diagnose acute and old myocardial infarction, and provides a new basis for the analysis of the causes of sudden cardiac death.
Subject(s)
Humans , Amides , Death, Sudden, Cardiac , Myocardial Infarction/pathology , Myocardium/pathology , Spectroscopy, Fourier Transform Infrared/methods , Forensic PathologyABSTRACT
Objective:To explore the relationship between fragmented QRS complex and heart rate variability (HRV) and ventricular arrhythmia in patients with old myocardial infarction.Methods:From August 2018 to October 2019, 200 patients with old myocardial infarction were first treated in the Department of cardiac function examination of the First Affiliated Hospital of Hebei North University. The patients were divided into 99 cases of old myocardial infarction with fragmented QRS wave group and 101 cases of old myocardial infarction without fragmented QRS wave group according to the case bank data and conventional 12 lead ECG diagnosis in our hospital for the first time. Then, the 24-h ambulatory ECG reexamined within 1 year after discharge was retrospectively analyzed. The incidence of ventricular arrhythmia was compared between the two groups by χ 2 test. The difference of heart rate variability between the two groups was compared by rank sum test. Multiple logistic regression was used to analyze the value of different indexes of heart rate variability in the evaluation of fragmented QRS complex in old myocardial infarction. Drawing the receiver operating characteristic (ROC), and the area under the curve (AUC) was used to analyze the diagnostic accuracy of different indexes of heart rate variability in the broken QRS complex of old myocardial infarction. Results:According to the Lown classification of ventricular premature contraction, the number of positive ventricular arrhythmias in patients with Grade Ⅰ of ventricular premature contraction and Grade Ⅲ-Ⅴ of ventricular premature contraction in the old myocardial infarction fragmented QRS group was higher than that in the old myocardial infarction non fragmented QRS group (Grade Ⅰ of ventricular premature contraction: 54.5% (54/99)and 39.6%(40/101); χ 2=4.484, P<0.05;Grade Ⅲ-Ⅴ of ventricular premature contraction: 34.3% (34/99) and 9.9%(10/101); χ 2=17.406, P<0.05)). Ventricular premature contraction Grade 0 old myocardial infarction fragmented QRS group was lower than old myocardial infarction non fragmented QRS group (8.1% (8/99) and 48.5% (49/101); χ 2=37.995, P<0.05). The total number of positive cases of ventricular arrhythmia in the old myocardial infarction group with fragmented QRS wave was higher than that in the old myocardial infarction group without fragmented QRS wave (91.9% (91/99) and 51.5%(52/101); χ 2=57.146, P<0.05)). There was no significant difference in the number of positive ventricular arrhythmias between the old myocardial infarction fragmentation QRS group and the old myocardial infarction non fragmentation QRS group ( P>0.05). The standard deviation of NN intervals (SDNN) and the standard deviation of average NN intervals (SDANN) of HRV time domain indexes in the old myocardial infarction fragmented QRS group were higher than those in the old myocardial infarction non fragmented QRS Group (SDNN:143.00(122.00,166.00) vs. 110.00(95.00,130.50), Z=5.780, P<0.05; SDANN:112.00(100.00,136.00) vs. 96.00(76.00,118.50), Z=4.013, P<0.05). Multiple Logistics regression analysis results of HRV domain shows that HRV time domain SDNN and SDANN have diagnositic value in diagnosis fQRS after OMI(SDNN: OR=0.949, 95% CI:0.922-0.977, P<0.001; SDANN: OR=1.036, 95% CI:1.005-1.068, P=0.022). Area under ROC curve of HRV time domain SDNN and SDANN have particular diagnositic accuracy in diagnosis fQRS after OMI(SDNN: AUC 0.737, 95% CI 0.666-0.807, Sensitivity 0.818, Specificity 0.634; SDANN: AUC 0.664, 95% CI 0.587-0.741, Sensitivity 0.737, Specificity 0.673. 0.5<AUC<1). Conclusion:Fragmented QRS complex was positively correlated with the incidence and severity of ventricular arrhythmia in patients with old myocardial infarction, and positively correlated with time-domain indexes SDNN and SDANN of heart rate variability in patients with old myocardial infarction.
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To set up rat myocardial infarction model and to investigate significance of fragmented QRS wave in rat myocardial infarction model.40 rats were divided into sham-operated group and myocardial infarction group, these two sets of rats received surgeries under the same conditions.Myocardial infarction models were induced by opening chest and anterior descending branch of coronary artery deligation for rats.Rats in sham-operated group were only threaded without deligation.Recorded the electrocardiogram(ECG) during 10, 60 min and 4 weeks after the deligation(or threading) and analyzed the change rules of the fragmented QRS waves and Q waves.Tissue samples from myocardial infarction area were collected for HE staining 4 weeks after the surgery.The frequency of fragmented QRS wave in myocardial infarction group was significantly increased during 10, 60 min and at 4 weeks after the operation compared with sham-operated group(P<0.01).Myocardial cells of some models in myocardial infarction group arranged in disorder and showed vacuolation according to results of HE staining.By setting up rat myocardial infarction model, we can draw a conclusion that fragmented QRS wave can be used as a new indicator to diagnose acute myocardial infarction and old myocardial infarction predict the severity of the disease.
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<p>A 66-year-old man presented to a local doctor with a chief complaints of episodes of dizziness lasting several seconds. Electrocardiographic findings were suggestive of arrhythmia and old myocardial infarction, and the patient was therefore referred to our hospital. Left ventriculography showed an aneurysm at the posteroinferior wall of the left ventricle, while coronary angiography showed chronic total occlusion of the left circumflex branch (segment 13) and a coronary-pulmonary artery fistula with a coronary aneurysm. On computed tomography, the orifice of the ventricular aneurysm was small, measuring approximately 10 mm. Magnetic resonance imaging showed wall thinning and mural thrombus in the ventricular aneurysm, with aneurysmal dilatation during systole. Suspecting a ventricular false aneurysm resulting from old myocardial infarction, left ventricular reconstructive surgery and resection of the coronary artery aneurysm were performed. Intraoperatively, myocardial necrosis of the posteroinferior wall accompanied by the ventricular aneurysm was seen. There was no pericardial adhesion to the ventricular aneurysm, and the diameter of the orifice of the aneurysm was approximately 10 mm. The ventricular aneurysm was cut open and then closed using a direct suture combined with patch repair. As for the coronary artery aneurysm, the inflow and outflow arteries were each clipped before the wound was closed. The patient had a favorable postoperative course and was discharged from the hospital on the 15th day after surgery. The pathological examination showed residual cardiomyocytes within the aneurysmal wall, thereby establishing the diagnosis of a pseudo-false aneurysm. Our experience with this rare case is reported.</p>
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Objective To investigate the effect of old myocardial infarction on the heart rate variability.Methods Totally 86 patients with old myocardial infarction and 78 healthy people were enrolled in the study.Twenty-four-hour heart rate variability in the time domains including NN,SDNN,SDANN,RMSSD,and PNN50 and the frequency domains including VLF,LF,HF,and LF/HF were analyzed.Results Both the time domain and frequency domain indexes of the heart rate variability in patients with old myocardial infarction significantly decreased than those in the healthy peolple（P 0.05）.Conclusion There might be autonomic nervous system dysfunction in the patients with old myocardial infarction.
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The aim of the present study was to assess whether Fourier transform infrared spectrometry (FTIR)micro-spectroscopy could produce distinct spectral information on protein of old myocardial infarction(OMI)and to set them as molecular markers to diagnose atypical OMI.Paraffin-embedded heart samples were derived from victims dying of OMI.In combination with histological stain,FTIR and infrared micro-spectroscopy,the characteristics of OMI were analyzed morphologicallyand molecularly.The most relevant bands identified were the amide A,B,Ⅰ and Ⅱ,showing crucial spectral differences between apparent normal region and OMI region,including the peak position blue shift and the increased intensity of OMI,moreover relative increase in a-helix and decrease in β-sheet of protein secondary structures in OMI.Comparing to single spectral band,the I1650/I1550 ratio was increased and rationally used as a molecular marker for diagnosing OMI.These novel preliminary findings supported further exploration of FTIR molecular profiling in clinical or forensic study,and were in accordance with histopathology.
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Objective:With biomechanical trial, the feasibility was investigated using the indentation method to assess myocardium viscoelasticity and the change of viscoelasticity after old myocardial infarction was also investigated. Method:The old myocardial infarction moldel was established using ligating the left anterior descending branch under thoracotomy.With the instrument of indentation, creep test was applied to the normal and old infarcted canine ventricular myocardium. Results:The viscoelastic parameteres of normal group:E164?9kPa,E2565?148kPa,E∞57?7kPa,?1.7?0.9?105kPa.s;old infarcted group: E1130?30kPa,E21076?466kPa,113?27kPa,?2.8?1.0?105kPa.s.The difference of parameteres in above two groups is significant in statistics(P