Out-of-hospital coronary heart disease death: acute pathological lesions.

BACKGROUND: The majority of deaths due to acute coronary heart disease (CHD) occur outside hospital, unexpectedly, within the first few hours following the onset of the terminal event. Data on the incidence and nature of acute pathological findings in the affected hearts as seen in routine autopsies are somewhat controversial. Detailed pathological examination of coronary arteries and myocardium of such decedents was performed to clarify the situation. METHODS AND RESULTS: Full autopsy and detailed macroscopic and microscopic examination of the coronary arteries and myocardium were performed in 170 men, all registered in the Kaunas Acute Myocardial Infarct Register, who died outside hospital of CHD within 6 hours from the onset of symptoms. Out-of-hospital coronary death was in all cases related to acute ischaemic myocardial lesions, either myocardial infarction (MI) in 92.9% of cases or patchy micronecrosis in 7.1%. In the former group, the following stages of acute infarction were found: early MI (hyperacute phase) in 48.8% of cases, definite MI (displaying grossly identifiable coagulative necrosis) in 21.8% and progressing MI (presence of signs of early MI adjacent to a healing infarction) in 22.3%. Signs of new thrombotic coronary events were found in relation to these acute ischaemic myocardial lesions in 88.8% of cases, as occlusive thrombus in 41.2%, non-occlusive, mural thrombus in 37.0% and microthrombi/microemboli in intramyocardial vessels in 10.6%. CONCLUSIONS: Out-of-hospital coronary death most commonly was related to the early or definite stages of myocardial infarction. Accurate identification of these acute ischaemic lesions was based on detailed microscopic examination of the entire ventricular myocardium, with consideration being paid to signs of cardiomyocyte involvement and early inflammatory reaction associated with it. Acute pathology of the affected coronary artery usually confirmed that these myocardial infarct lesions were the cause of the sudden out of-hospital CHD-related deaths.

Nonlinear dynamics analysis of electrocardiograms for detection of coronary artery disease.

A computerized approach of nonlinear dynamics analysis of electrocardiogram (ECG) signals was applied for the detection of coronary artery disease (CAD). The proposed nonlinear dynamics descriptors were derived from 12-lead rest ECG data, and evaluated by originally developed computer software. Fluctuations of potentials of ECG leads that occur during the period of 20 ms with a magnitude of 5-20 microV were significantly less beat-to-beat predictable in ischemic versus non-ischemic patients. The well-known nonlinear dynamics descriptors, recurrences percentage, mutual information, fractal dimension, and a new descriptor, next embedding dimension error, were good quantitative descriptors of fluctuations. They were significantly different (< p = 0.00001) in males with (108 patients) and without (54 patients) coronary artery lesions. The analysis of small fluctuations required a careful preprocessing technique based on knowledge of specifics of measurement errors and physiology of ECG signals. We considered finite differences of measured potentials with the time step of 20 ms as the initial source for nonlinear analysis. In nonlinear dynamics analysis, we also included such time moments that only belong to P- and T-waves or baseline drift with small positive slopes that allowed us to extract, under normal conditions, initial halves of P- and T-waves that displayed a better capacity to classify ischemic patients.

[Myocardial pathology in sudden ischemic death: peculiarities of morphologic diagnosis]. / Nuo isemines sirdies ligos staiga mirusiuju miokardo patologija: morfologines diagnostikos ypatybes.

OBJECTIVE: The aim of the investigation was to determine morphological criteria of acute myocardial injures in sudden ischemic death. MATERIAL AND METHODS: Morphological investigation of the whole myocardium and coronary arteries in 170 victims of sudden out-of-hospital death due to ischemic heart disease was performed in the framework of the international WHO program "Myocardial Infarction Register in Population" and joint (at that time) USSR-USA project on sudden death. RESULTS: It was established, that out-of-hospital sudden death due to ischemic heart disease in all cases is related to irreversible myocardial injury: 92.9% - to acute myocardial infarction, and 7.1% - to micronecrosis. The following phases of morphological development of infarction were determined: early myocardial infarction--in 48.8, definite--in 21.8, and progressing--in 22.3%. Since the signs of early infarction were also found in 34 cases of progressing myocardial infarction, it was reasonable to suppose that in 117 (71.1%) patients the occurrence of sudden out-of-hospital death due to ischemic heart disease was somehow connected with the very early and early phases of acute myocardial infarction. CONCLUSIONS: Accurate identification of early myocardial infarction is available only by microscopic investigation of histotopograms of the whole myocardium considering the complex of signs of cardiomyocyte alteration as well as early inflammatory reaction. Acute pathology (erosion or rupture of atherosclerotic plaque and thrombosis) of "culprit" coronary artery indirectly indicates regional myocardial irreversible injury.