Different types of myocardial necrosis in coronary heart disease: a pathophysiologic review of their functional significance

Clinicopathological correlations in heart transplantation recipients complicated by death or re-transplantation

Purpose

This study aimed to identify and correlate pathological findings with clinical outcomes in patients after orthotopic heart transplantation (OHT) who either died or underwent a re-transplantation.

Methodology and study design

Single-center retrospective analysis of primary OHT patients who died or were re-transplanted between October 2012 and July 2021. Clinical data were matched with corresponding pathological findings from endomyocardial biopsies on antibody-mediated rejection, cellular rejection, and cardiac allograft vasculopathy. Re-assessment of available tissue samples was performed to investigate acute myocardial injury (AMI) as a distinct phenomenon. These were correlated with clinical outcomes, which included severe primary graft dysfunction. Patients were grouped according to the presence of AMI and compared.

Results

We identified 47 patients with truncated outcomes after the first OHT. The median age was 59 years, 36 patients (76%) were male, 25 patients (53%) had a prior history of cardiac operation, and 21 patients (45%) were supported with a durable assist device before OHT. Of those, AMI was identified in 22 (47%) patients (AMI group), and 25 patients had no AMI (non-AMI group). Groups were comparable in baseline and perioperative data. Histopathological observations in AMI group included a non-significant higher incidence of antibody-mediated rejection Grade 1 or higher (pAMR ≥ 1) (32% vs. 12%, P = 0.154), and non-significant lower incidence of severe acute cellular rejection (ACR ≥ 2R) (32% vs. 40%, P = 0.762). Clinical observations in the AMI group found a significantly higher occurrence of severe primary graft dysfunction (68% vs. 20%, P = 0.001) and a highly significant shorter duration from transplantation to death or re-transplantation (42 days [IQR 26, 120] vs. 1,133 days [711–1,664], P < 0.0001). Those patients had a significantly higher occurrence of cardiac-related deaths (64% vs. 24%, P = 0.020). No difference was observed in other outcomes.

Conclusion

In heart transplant recipients with a truncated postoperative course leading to either death or re-transplantation, AMI in endomyocardial biopsies was a common pathological phenomenon, which correlated with the clinical occurrence of severe primary graft dysfunction. Those patients had significantly shorter survival times and higher cardiac-related deaths. The presence of AMI suggests a truncated course after OHT.

Contraction Band Necrosis with Dephosphorylated Connexin 43 in Rat Myocardium after Daily Cocaine Administration

Contraction band necrosis (CBN) is a common abnormality found in the myocardium of cocaine abusers, but is rarely reported in experimental models of cocaine abuse. Connexin 43 (Cx43) is essential for cardiac intercellular communication and the propagation of CBN. Under stress or injury, cardiac Cx43 is dephosphorylated, which is related to cardiomyocyte dysfunction and pathogenesis, whereas adiponectin exerts beneficial effects in the myocardium. In this study, we explore the effects of cocaine on cardiac Cx43 in vivo. Rats were administered cocaine via the tail vein at 20 mg/kg/day for 14 days, and showed widespread CBN, microfocal myocarditis and myocardial fibrosis, corresponding to a dysfunction of cardiac mitochondria under increased oxidative stress. The increase in dephosphorylated cardiac Cx43 and its negative correlation with the myocardial distribution of CBN after cocaine administration were determined. In addition, apoptosis and necroptosis, as well as increased adiponectin levels, were observed in the myocardium after cocaine exposure. Accordingly, we found altered profiles of cardiac Cx43, CBN and its negative correlation with dephosphorylated cardiac Cx43, and the possible involvement of adiponectin in the myocardium after 14 days of cocaine administration. The latter might play a protective role in the cardiotoxicity of cocaine. The current findings would be beneficial for establishing novel therapeutic strategies in cocaine-induced cardiac consequences.

Morphologic Markers of Acute and Chronic Stress in Child Abuse

OBJECTIVES

To elucidate pathologic markers of acute and chronic stress found but rarely reported in chronic child abuse.

METHODS

Autopsies of 3 cases of fatal child abuse with well-documented chronic maltreatment are reported, with an emphasis on the nontraumatic findings of acute and chronic stress.

RESULTS

Besides the overwhelming physical injuries, all 3 children and 1 additional case obtained for consultation had telogen effluvium, a form of alopecia well known to be associated with stress in adults and some children but never reported in chronic abuse. All 3 had the microscopic findings of markedly involuted thymus, a well-known marker of physiologic stress in children but only occasionally referred to in child abuse. All 3 also had microscopic findings of myocardial necrosis associated with supraphysiologic levels of catecholamine, a well-documented finding associated with stress but rarely reported in fatalities associated with child abuse. Two of the 3 children also had Anitschkow-like nuclear changes in cardiac tissue, markers associated with prior, nonischemic myocardial pathologies that may be associated with prior episodes of acute stress.

CONCLUSIONS

Pathologists are urged to explore these markers as supportive evidence in their own investigations of possible child abuse fatalities, especially when associated with stress.

Effect of CD14 polymorphisms on the risk of cardiovascular disease: evidence from a meta-analysis

Background

CD14 polymorphisms are associated with an increased risk of cardiovascular events. So far, many studies have been conducted, whereas the results were not always consistent.

Materials and methods

Twenty-six articles involving thirty-seven datasets were recruited to evaluate the association between rs2569190 (9413 patients and 7337 controls), C-159T (4813 patients and 2852 controls) polymorphisms and cardiovascular diseases in a meta-analysis. The random or fixed effect models were used to evaluate the pooled odds ratios (ORs) and their corresponding 95% confidence intervals.

Results

The strongest association was observed between rs2569190 and CVD in overall population (T vs. C, OR = 1.169, 95% CI: 1.087–1.257, p = 2.44 × 10^− 5). Analysis after stratification by ethnicity indicated that rs2569190 was related to CVD in East Asian population (T vs. C, OR = 1.370, 95% CI; 1.226–1.531, p = 2.86 × 10^− 8) and a potential relationship in European (T vs. C, OR = 1.100, 95% CI: 1.019–1.189, p = 0.015). In the stratification of endpoints, the associations were found in CHD subgroup (T vs. C, OR = 1.357, 95% CI: 1.157–1.592, p = 2.47 × 10^− 7) and in AMI subgroup (T vs. C, OR = 1.152, 95% CI: 1.036–1.281, p = 0.009). However, we did not find any association between C-159T polymorphism with cardiovascular disease under any model.

Conclusions

The SNP rs2569190 significantly contribute to susceptibility and development of cardiovascular disease, particularly in the East Asian population and in the subtype CHD group, in addition, a potential association was observed in the AMI group, T allele acts as a risk factor for cardiovascular disease.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1018-3) contains supplementary material, which is available to authorized users.

miR-200a-5p regulates myocardial necroptosis induced by Se deficiency via targeting RNF11

Necroptosis has been discovered as a new paradigm of cell death and may play a key role in heart disease and selenium (Se) deficiency. Hence, we detected the specific microRNA (miRNA) in response to Se-deficient heart using microRNAome analysis. For high-throughput sequencing using Se-deficient chicken cardiac tissue, we selected miR-200a-5p and its target gene ring finger protein 11 (RNF11) based on differential expression in cardiac tissue and confirmed the relationship between miR-200a-5p and RNF11 by dual luciferase reporter assay and real-time quantitative PCR (qRT-PCR) in cardiomyocytes. We further explored the function of miR-200a-5p and observed that overexpression of miR-200a-5p spark the receptor interacting serine/threonine kinase 3 (RIP3)-dependent necroptosis in vivo and in vitro. To understand whether miR-200a-5p and RNF11 are involved in the RIP3-dependent necroptosis pathway, we presumed that oxidative stress, inflammation response and the mitogen-activated protein kinase (MAPK) pathway might trigger necroptosis. Interestingly, necroptosis trigger, z-VAD-fmk, failed to induce necroptosis but enhanced cell survival against necrosis in cardiomyocytes with knockdown of miR-200a-5p. Our present study provides a new insight that the modulation of miR-200a-5p and its target gene might block necroptosis in the heart, revealing a novel myocardial necrosis regulation model in heart disease.

Troponin T in Prediction of Culprit Lesion Coronary Artery Disease and 1-Year Major Adverse Cerebral and Cardiovascular Events in Patients with Acute Stroke

Troponin T (TnT) elevation above the 99th percentile upper reference limit (URL) is considered diagnostic of acute myocardial infarction (MI). Non-specific increases of TnT are frequent in acute stroke patients. However, in these patients, correct diagnosis of MI is crucial because the antithrombotic medications used to treat acute MI might be harmful and produce intracranial bleeding. In this study, we aimed to associate enhanced TnT levels defined by different cutoff values with occurrence of culprit lesion coronary artery disease (CAD) as well as 1-year major adverse cerebral and cardiovascular events (MACCEs). In this cohort study, we investigated 84 consecutive patients with acute ischemic stroke and concomitant MI. TnT levels were measured using a fourth-generation TnT assay. The incidence of culprit lesion CAD was determined by coronary angiography. MACCEs were recorded during 1-year follow-up. Culprit lesion CAD occurred in 55 % of patients, and 1-year MACCE in 37 %. TnT levels above the manufacturers' provided 99th URL (TnT > 0.01) were not associated with culprit lesion CAD (relative risk [RR], 1.3; 95 % confidence interval [CI] 0.96-1.8; P = 0.09). Slightly increased cutoff level (TnT > 0.03) increased specificity and was associated with culprit lesion CAD without decreasing sensitivity (RR, 1.5; 95 % CI 1.1-2.2; P = 0.021) and 1-year MACCE (RR, 1.7; 95 % CI 1.3-2.3; P < 0.001). Slightly increasement of the TnT cutoff level predicted MACCEs and is superior in prediction of culprit lesion CAD in stroke patients without being less sensitive. This finding has to be confirmed in large-scale clinical trials.

Stress echocardiography as a gatekeeper to donation in aged marginal donor hearts: anatomic and pathologic correlations of abnormal stress echocardiography results

BACKGROUND

Owing to the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Pharmacologic stress echocardiography is highly accurate in identifying prognostically significant coronary artery disease, but brain death and catecholamine storm in potential heart donors may substantially alter the cardiovascular response to stress. This study assessed correlates of an abnormal resting/stress echocardiography results in potential donors.

METHODS

From April 2005 to December 2007, 18 marginal candidate donors (9 men) aged 58 +/- 5 years were initially enrolled. After legal declaration of brain death, all marginal donors underwent bedside echocardiography, with baseline and (when resting echocardiography was normal) dipyridamole (0.84 mg/kg in 6 min) or dobutamine (up to 40 microg/kg/min) stress echo. Non-eligible hearts (with abnormal rest or stress echo findings) were excluded and underwent cardioautoptic verification.

RESULTS

Resting echocardiography showed wall motion abnormalities in 5 patients (excluded from donation). Stress echocardiography was performed in the remaining 13 (dipyridamole in 11; dobutamine in 2). Results were normal in 7, of which 6 were uneventfully transplanted in marginal recipients. Results were abnormal in 6, and autoptic verification performed showed coronary artery disease in 5, and initial cardiomyopathy in 1.

CONCLUSIONS

Bedside pharmacologic stress echocardiography can safely be performed in candidate heart donors, is able to unmask occult coronary artery disease or cardiomyopathy, and shows potential to extend donor criteria in heart transplantation. Further experience with using marginal donors is needed before exact guidelines can be established.

Attempted diagnosis of ventricular mural thrombi in acute mycardial infarction using 125I-labelled fibrinogen

In an attempt to diagnose ventricular mural thrombi complicating acute myocardial infarction (AMI), 80 patients have been given 100 muCi 125I-labelled fibrinogen after admission to a CCU. Precordial radioactivity was recorded for the following 6 days over four sites corresponding to chest leads CR1-CR4. A sustained rise in radioactivity of at least 15% of initial recordings was classed as type A pattern, a minor rise or flattened response as type B pattern and a rapid decrease as type C pattern; 28% showed a type A, 19% a type B and 54% a type C pattern. There was no significant difference between the groups in incidence of pericardial friction rub but when patients with suspected pericarditis (as evidenced by characteristic pains) were added, pericarditis was significantly overrepresented in the type A group. Smaller infarctions (SGOT less than 100 U/1) were significantly more common in patients with a type C decay pattern. No differences were noted between the groups as regards type and site of the infarction. A sustained rise in precordial radioactivity after an AMI may be an indication of mural thrombosis but the influence of other factors secondary to an infarction, e.g. pericarditis, cannot be determined at present.

Myocardial scintigraphy with 99mTc-pyrophosphate in patients with unstable angina pectoris

A total of 400 patients, aged 25-82 years, admitted to the Coronary Care Unit due to clinical suspicion of acute myocardial infarction, were examined with 10 mCi 99mTc labelled to pyrophosphate. The examinations were carried out 4-120 hours post onset of symptoms, with a mobile gamma camera. Scintigrams were evaluated with regard to presence, localization and intensity of an uptake. Among 249 patients with a verified acute myocardial infarction, uptake was found in 237. Sixty-two of 85 patients with unstable angina showed a diffuse uptake with low intensity. Scintigraphy could not be used as a prognostic index of which patients would later develop an infarct. However, the scintigraphic pattern was useful as an aid in the differential diagnosis between acute myocardial infarction and unstable angina.

Hemodynamic effects of the cardioselective beta-blocking agent metoprolol in acute myocardial infarction. A 24-hour catheterization study

Hemodynamic changes were studied in ten patients with uncomplicated transmural myocardial infection during 24 hours on beta-blockade. The cardioselective beta-adrenergic blocking drug metoprolol was injected (15 mg i.v.) within the first 24 hours after onset of chest pain and was followed by oral therapy (25-50 mg at 6-hour intervals). There was a decrease in heart rate, systolic BP, and cardiac output, which was most marked after the injection. The stroke volume and diastolic BP for the whole group of patients remained unchanged. The pulmonary artery end diastolic pressure did not change significantly after the injection but a continuous fall was obtained in three out of four patients with initially elevated values. The preejection period, measured from the ECG and carotid pressure curve, as initially short and was prolonged in all patients after administration of the beta-blocking drug. It is concluded that the cardioselective beta-blocking drug metoprolol may be used in selected patients in the acute phase of myocardial infarction without danger of hemodynamic deterioration during the first 24 hours of therapy. The selection of patients can be based on clinical criteria. In this study signs of left heart failure, hypotension, poor peripheral circulation, bradycardia, and AV block were regarded as contraindications.

Auricular tyrosine hydroxylase and dopamine-beta-hydroxylase activities and noradrenaline content in ischaemic heart disease

Assessments were made of the tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) activities as well as the noradrenaline (NA) content of samples excised from right auricular tissue during cardiac surgery on a total of 55 patients with ischaemic heart disease (IHD), valvular heart disease (VHD), uncomplicated atrial septal defect (ASD) or congestive heart failure (CHF). The NA content was significantly higher in the IHD group than in the other three groups. The TH activity was highest in the IHD group although the difference was statistically significant only compared with the ASD and CHF groups. The DBH activity was also highest in the IHD group, but again the difference was statistically significant only compared with the ASD and CHF groups. In the whole material there was a significant positive correlation between the NA content and TH or DBH activity, as well as between TH and DBH activity. In the IHD group there was a significant positive correlation between heart volume and TH activity. The results suggest that at least compared with ASD and CHF, the sympathetic tone is relatively high in IHD, possibly involving an enhanced NA turnover.

Cardiomyocyte death and renewal in the normal and diseased heart

During post-natal maturation of the mammalian heart, proliferation of cardiomyocytes essentially ceases as cardiomyocytes withdraw from the cell cycle and develop blocks at the G0/G1 and G2/M transition phases of the cell cycle. As a result, the response of the myocardium to acute stress is limited to various forms of cardiomyocyte injury, which can be modified by preconditioning and reperfusion, whereas the response to chronic stress is dominated by cardiomyocyte hypertrophy and myocardial remodeling. Acute myocardial ischemia leads to injury and death of cardiomyocytes and nonmyocytic stromal cells by oncosis and apoptosis, and possibly by a hybrid form of cell death involving both pathways in the same ischemic cardiomyocytes. There is increasing evidence for a slow, ongoing turnover of cardiomyocytes in the normal heart involving death of cardiomyocytes and generation of new cardiomyocytes. This process appears to be accelerated and quantitatively increased as part of myocardial remodeling. Cardiomyocyte loss involves apoptosis, autophagy, and oncosis, which can occur simultaneously and involve different individual cardiomyocytes in the same heart undergoing remodeling. Mitotic figures in myocytic cells probably represent maturing progeny of stem cells in most cases. Mitosis of mature cardiomyocytes that have reentered the cell cycle appears to be a rare event. Thus, cardiomyocyte renewal likely is mediated primarily by endogenous cardiac stem cells and possibly by blood-born stem cells, but this biological phenomenon is limited in capacity. As a consequence, persistent stress leads to ongoing remodeling in which cardiomyocyte death exceeds cardiomyocyte renewal, resulting in progressive heart failure. Intense investigation currently is focused on cell-based therapies aimed at retarding cardiomyocyte death and promoting myocardial repair and possibly regeneration. Alteration of pathological remodeling holds promise for prevention and treatment of heart failure, which is currently a major cause of morbidity and mortality and a major public health problem. However, a deeper understanding of the fundamental biological processes is needed in order to make lasting advances in clinical therapeutics in the field.

Ultrasound imaging versus morphopathology in cardiovascular diseases. Myocardial cell damage

This review article summarizes the results of histopathological and clinical imaging studies to assess myocardial necrosis in humans. Different histopathological features of myocardial cell necrosis are reviewed. In addition, the present role of echocardiographic techniques in assessing irreversible myocardial damage is briefly summarized.

Apoptosis and oncosis in acute coronary syndromes: assessment and implications

The rational design of therapeutic interventions for protection of ischemic myocardium from ultimate death requires an understanding of the mechanistic basis of cardiomyocyte (CM) cell death, its timing and the tools for its quantification. Until recently, CM cell death following ischemia and/or reperfusion was considered to involve necrosis or 'accidental cell death' from very early on. Collective evidence over the past decade indicates that early CM cell death after myocardial ischemia and post-ischemic reperfusion involves apoptosis with cell shrinkage and drop-out, and/or oncosis with cell swelling followed by necrosis. This paradigm shift suggests that different approaches for cardioprotection are required. Oncologists, pathologists, anatomists and basic scientists who have studied apoptosis over the last three decades separated physiological apoptosis from inappropriate apoptosis in pathological states. Until recently, cardiologists resisted the concepts of CM apoptosis and regeneration. Cumulative evidence indicating that apoptosis in the heart may occur in different cell types, spread from one cell type to another, and occur in bursts, may have profound implications for therapies aimed at protection of ischemic myocardium by targeting CM apoptosis in acute coronary syndromes. This review focuses on a critique of the methods used for the assessment of CM apoptosis and the implications of CM apoptosis in acute coronary syndromes.

Discrimination of Recent Ischemic Myocardial Changes in WHHLMI Rabbits from the Findings of Postmortem Degeneration

To distinguish recent ischemic myocardial changes in myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits from general postmortem myocardial degeneration, we examined hearts of WHHLMI rabbits after sudden death and postmortem hearts of non-atherogenic rabbits. Hearts of 8 WHHLMI rabbits were excised within 30 min of sudden death and hearts of 27 non-atherosclerotic rabbits were excised at designated periods after sacrifice. A large number of myocardial cells from WHHLMI rabbits exhibited features characteristic of ischemia (intercellular gap, intracellular edema, eosinophilia, disappearance of myocardial cells, indistinct nuclei, wavy myocardial fibers) simultaneously at regions close to proximal occluded coronary arteries. Although postmortem hearts of non-atherosclerotic rabbits exhibited similar characteristics, several features characteristic of autolyzed myocytes were also randomly observed in the left ventricle wall. Each feature was detected independently in myocardial cells or regions of the ventricle wall. In conclusion, we found several unique characteristics associated with myocardial infarction which enable discrimination between recent ischemic myocardial changes and myocardial degeneration following death.

Myocardial necrosis after envenomation by the scorpion Tityus serrulatus

A 4 years old boy died a few hours after he had been stung by a scorpion (Tityus serrulatus). At necropsy, there were multiple foci of coagulative myocytolysis in the myocardium and pulmonary oedema. Myocardial necrosis was probably associated with the sympathetic storm induced by scorpion envenomation, and may have contributed to cardiac failure and death.

Histologic appearance of fractured thyroid cartilage and surrounding tissues

Histological appearances of the fractured superior horns (SH) of the thyroid cartilage and their surrounding tissues were reviewed, with particular reference to signs of vital origin of the fracture. Twenty-nine autopsies with either histories or findings indicating asphyxial neck compression, with a total of 39 fractured SHs, and three autopsies with history of suicidal jump from height with a total of two SH fractures, were examined. Fifteen autopsies with finding of 19 artefactually fractured SHs while removing neck organs at autopsy were used as controls. In the cases of neck compression and victims of jump from height haemorrhages, retraction of fractured SH fragments with invagination or squeezing of the perichondrium, contraction bands, contraction band necrosis and 'opaque fibres', in the adjacent muscle fibres could be seen. Fibrin deposition and/or leucocytic reaction were noted in cases where circumstances of death indicated prolonged death struggle (as in incomplete hanging, resuscitation or homicidal neck compression). However, retraction of fractured fragments and invagination of perichondrium between artefactually fractured SH fragments were observed in both control cases and cases with antemortem trauma to the larynx. Many of these histological findings, including haemorrhages and fractures had not been evident at gross examination. We conclude that histological examination of SHs may not only uncover macroscopically overlooked injuries but also may facilitate the clarification of an injury's vital origin.

Sequential changes in localization of repair-related proteins (heat shock protein 70, ubiquitin and vascular endothelial growth factor) in the different stages of myocardial infarction

AIMS

The myocardium expresses vascular endothelial growth factor (VEGF), heat shock protein 70 (HSP70), and ubiquitin immediately after the onset of cardiac ischaemia. This study demonstrated the sequential changes in localization of these proteins, in addition to fibronectin and troponin T (TnT), in human hearts with myocardial infarction (MI).

METHODS AND RESULTS

Myocardial tissues from 40 autopsied MI cases were immunostained with the five antibodies against VEGF, HSP70, ubiquitin, fibronectin and TnT. Fibronectin was recognized only in the cardiomyocytes with infarction. Although TnT, HSP70, ubiquitin and VEGF were detected in the affected myocardium in the early stages, their expression in cardiomyocytes around infarcted foci were more intense. The cardiomyocytes with coagulative myocytolysis were positive for fibronectin, but negative or weakly positive for TnT, HSP70, ubiquitin and VEGF. In contrast, the cardiomyocytes with colliquative myocytolysis were strongly positive for TnT, HSP70, ubiquitin and VEGF, but negative for fibronectin.

CONCLUSIONS

Immunostaining using antibodies to fibronectin, TnT, HSP70, ubiquitin and VEGF is useful for the discrimination between infarcted myocytes and ischaemia-damaged myocytes in the human heart with MI at autopsy.

Histologic and biochemical study of the brain, heart, kidney, and liver in asphyxia caused by occlusion of the umbilical cord in near-term fetal lambs

OBJECTIVE

We sought to determine the relationship between the degree of histologic changes in the brain, heart, kidney, and liver in fetal lambs after severe asphyxia and to analyze the role of oxidative stress in the pathogenesis of fetal multiple organ failure.

STUDY DESIGN

Eight chronically instrumented near-term fetal lambs were asphyxiated by partial umbilical cord occlusion for approximately 60 minutes until the fetal arterial pH reached <6.9 and the base excess reached <-20 mEq/L. An additional 6 fetuses were used as sham-asphyxiated controls. Fetal heart rates, blood pressure, fetal breathing movements, and arterial blood gases and acid-base states were serially monitored. The brain, heart, kidney, and liver were collected 72 hours after asphyxia, processed, and histologically examined after hematoxylin and eosin staining. Fetal brain histologic features were classified into 5 grades, with 5 being the most severe damage. The other organs were examined histologically by pathologists who were blinded to the treatment. Each organ was assayed for tissue concentrations of thiobarbituric acid-reactive substances, superoxide dismutase, glutathione, lactate, and glucose.

RESULTS

Myocardial changes of necrosis, phagocytosis, and contraction bands occurred in only 2 of the most severely (grade 5) brain-damaged fetuses. The same 2 cases showed fatty changes and congestion in the liver. In the kidney all asphyxiated cases showed tubular necrosis, but glomeruli were generally spared. Of the measures of oxidative stress, only liver tissue levels of thiobarbituric acid-reactive substances and superoxide dismutase were significantly higher in the asphyxiated group than in the control group, but there was no correlation with the degree of damage. Lactate level was higher only in the heart in the asphyxiated fetuses.

CONCLUSION

Renal tubular damage was seen with all degrees of asphyxia, despite variable brain damage. Histologic changes in the myocardium and liver were seen only with the most severe brain damage. Oxidative stress appears to play a role in the pathogenesis of liver damage.

Effects of the prostanoid EP3-receptor agonists M&B 28767 and GR 63799X on infarct size caused by regional myocardial ischaemia in the anaesthetized rat

1. This study investigates the effects of two agonists of the prostanoid EP3-receptor (M&B 28767 and GR 63799X) on the infarct size caused by regional myocardial ischaemia and reperfusion in the anaesthetized rat. 2. One hundred and sixty-seven, male Wistar rats were anaesthetized (thiopentone, 120 mg kg(-1) i.p.), ventilated (8-10 ml kg(-1), 70 strokes min(-1), inspiratory oxygen concentration: 30%; PEEP: 1-2 mmHg) and subjected to occlusion of the left anterior descending coronary artery (LAD, for 7.5, 15, 25, 35, 45 or 60 min) followed by reperfusion (2 h). Infarct size was determined by staining of viable myocardium with a tetrazolium stain (NBT), histological evaluation by light and electron microscopy and determination of the plasma levels of cardiac troponin T. 3. M&B 28767 (0.5 microg kg(-1) min(-1), i.v., n=7) or GR 63799X (3 microg kg(-1) min(-1), i.v., n=7) caused significant reductions in infarct size from 60+/-3% (25 min ischaemia and 2 h reperfusion; saline-control, n=8) to 39+/-6 and 38+/-4% of the area at risk, without causing a significant fall in blood pressure. Pretreatment of rats with 5-hydroxydecanoate (5-HD), an inhibitor of ATP-sensitive potassium channels, attenuated the cardioprotective effects of both EP3-receptor agonists. The reduction in infarct size afforded by M&B 28767 was also abolished by glibenclamide and the protein kinase C (PKC) inhibitors staurosporine and chelerythrine. 4. Thus, M&B 28767 and GR 63799X reduce myocardial infarct size in the rat by a mechanism(s) which involves the activation of PKC and the opening of ATP-sensitive potassium channels.

Orphan neurones and amine excess: the functional neuropathology of Parkinsonism and neuropsychiatric disease

The aetiology and treatment of Parkinsonism is currently conceptualised within a dopamine (DA) deficiency-repletion framework. Loss of striatal DA is thought to cause motor impairment of which tremor, bradykinaesia and rigidity are prominent features. Repletion of deficient DA should at least minimise parkinsonian signs and symptoms. In Section 2, based on extensive pre-clinical and clinical findings, the instability of this approach to Parkinsonism is scrutinised as the existing negative findings challenging the DA deficiency hypothesis are reviewed and reinterpreted. In Section 3 it is suggested that Parkinsonism is due to a DA excess far from the striatum in the area of the posterior lateral hypothalamus (PLH) and the substantia nigra (SN). This unique area, around the diencephalon/mesencephalon border (DCMCB), is packed with many ascending and descending fibres which undergo functional transformation during degeneration, collectively labelled 'orphan neurones'. These malformed cells remain functional resulting in pathological release of transmitter and perpetual neurotoxicity. Orphan neurone formation is commonly observed in the PLH of animals and in man exhibiting Parkinsonism. The mechanism by which orphan neurones impair motor function is analogous to that seen in the diseased human heart. From this perspective, to conceptualise orphan neurones at the DCMCB as 'Time bombs in the brain' is neither fanciful nor unrealistic [E.M. Stricker, M.J. Zigmond, Comments on effects of nigro-striatal dopamine lesions, Appetite 5 (1984) 266-267] as the DA excess phenomenon demands a different therapeutic approach for the management of Parkinsonism. In Section 4 the focus is on this novel concept of treatment strategies by concentrating on non-invasive, pharmacological and surgical modification of functional orphan neurones as they affect adjacent systems. The Orphan neurone/DA excess hypothesis permits a more comprehensive and defendable interpretation of the interrelationship between Parkinsonism and schizophrenia and other related disorders.

Myocardial kinetics of technetium-99m teboroxime in the presence of postischemic injury, necrosis and low flow reperfusion

OBJECTIVES

This study evaluated technetium-99m (Tc-99m) teboroxime kinetics in postischemic and partially necrotic myocardium with complete and low flow reperfusion using an isolated perfused rat heart model.

BACKGROUND

Technetium-99m teboroxime has been proposed for use in the early diagnosis of reperfusion after thrombolysis on the basis of models of myocardial necrosis with complete reperfusion. Clinically, however, reperfusion is frequently incomplete, resulting in a mixture of necrotic, ischemic and postischemic tissue.

METHODS

Hearts were classified into five groups: group 1 (n = 8, control); group 2 (n = 7, 30 min of no flow with complete reperfusion); group 3 (n = 12, 60 min of no flow to induce partial necrosis, followed by complete reperfusion); group 4 (n = 8, continuous low flow without flow interruption); and group 5 (n = 9, 60 min of no flow with low flow reperfusion). Buffer containing Tc-99m teboroxime was perfused for 15 min, followed by tracerfree buffer for 35 min, to evaluate uptake and clearance, respectively.

RESULTS

Uptake slopes for groups 1 to 5 were (mean +/- SD) 3.0 +/- 0.7, 2.6 +/- 0.8, 2.1 +/- 0.5, 0.8 +/- 0.2 and 0.8 +/- 0.3, respectively (p < or = 0.0005 for groups 1, 2 and 3 vs. groups 4 and 5, and p = 0.003 for group 3 vs. groups 1 and 2). Clearance curves from groups 1 to 3 were best fit by a biexponential function (p < 0.001); those from groups 4 and 5 were monoexponential. In groups 1, 2 and 3, the initial clearance rate constants (ki) (0.9 +/- 0.5 x 10(-3); 1.0 +/- 0.2 x 10(-3); 1.1 +/- 0.5 x 10(-3) s-1, respectively) and the monoexponential rate constants (Kmono) (2.0 +/- 0.3 x 10(-4); 2.2 +/- 0.4 x 10(-4); 2.1 +/- 0.2 x 10(-4) s-1, respectively) were significantly greater than those in groups 4 and 5 (0.9 +/- 0.5 x 10(-4); 1.2 +/- 0.3 x 10(-4) s-1, respectively, p < or = 0.005).

CONCLUSIONS

The uptake and initial clearance kinetics of Tc-99m teboroxime depend mainly on myocardial flow in this model. The presence of partial necrosis and postischemic injury has little effect on the initial clearance but leads to some reduction in uptake at normal flow rates. Evaluation of Tc-99m teboroxime kinetics may permit early noninvasive detection of inadequate reperfusion in acute myocardial infarction.

Necropsy study of the association between sudden cardiac death, cardiac isoenzymes and contraction band necrosis

AIMS

To assess whether a quantitative analysis of myocardial contraction bands could aid the postmortem identification of early myocardial infarction, especially if used in conjunction with cardiac isoenzyme activities.

METHODS

Sixty four coroner's necropsies were grouped by gross and histological findings into 26 cases of definite non-cardiac death, 12 cases of definite myocardial infarction and 26 cases in which there was occlusive coronary artery atheroma, but no demonstrable evidence of infarction. Using multiple sections of left ventricular myocardium stained with Heidenhain's iron haematoxylin, the number of myocardial cells containing contraction bands per unit area was quantified. The results were analysed statistically using logistic regression, and were then compared and combined with results from the statistical analysis of postmortem cardiac isoenzymes that had recently been undertaken on the same cases.

RESULTS

The number of cells containing contraction bands per unit area was higher in cases of definite myocardial infarction compared with those of non-cardiac deaths. In addition, cases of occlusive coronary artery atheroma only could be identified, indicating the presence of early myocardial infarction. The accuracy of this identification could be improved by combining these results with the results from the statistical analysis of postmortem cardiac isoenzymes.

CONCLUSION

The quantitative assessment of myocardial contraction band necrosis can provide useful additional information in cases of sudden death, where myocardial infarction is suspected but not identified on routine histological staining. The value of the information obtained is increased when used in conjunction with the postmortem measurement of cardiac isoenzyme activities.

Limitation of infarct expansion and ventricular remodeling by late reperfusion. Study of time course and mechanism in a rat model

BACKGROUND

Reperfusion of acutely infarcted myocardium may be beneficial in limiting infarct expansion and ventricular remodeling even if established after the time that salvage of ischemic myocardium is possible.

METHODS AND RESULTS

To examine the permanency, time course, and mechanism of this effect of late reperfusion, 200 rats were randomized into one of four groups: (1) infarction with reperfusion after 1 to 2 hours, (2) infarction with reperfusion after 6 to 8 hours, (3) infarction without reperfusion, and (4) sham operation. Surviving rats were killed at either 7 days, when infarct expansion has plateaued, or 21 days, when infarct healing is complete. In both 7- and 21-day analyses, late reperfusion did not reduce infarct size or degree of transmural necrosis but significantly limited infarct expansion, as measured by an index based on infarct endocardial segment lengthening and infarct wall thinning (expansion index at 7 days: no reperfusion, 2.73 +/- 0.25, n = 13; reperfusion after 1 to 2 hours, 1.56 +/- 0.13, n = 23, P < .001; reperfusion after 6 to 8 hours, 1.78 +/- 0.15, n = 16, P = .002; at 21 days: no reperfusion, 3.45 +/- 0.39, n = 13; reperfusion after 1 to 2 hours, 2.21 +/- 0.24, n = 15, P = .01; reperfusion after 6 to 8 hours, 2.02 +/- 0.20, n = 9, P = .01). Reperfusion after 6 to 8 hours was equally effective in limiting expansion as reperfusion after 1 to 2 hours. Late reperfusion also significantly reduced ventricular remodeling at 21 days, as measured by an index based on left ventricular cavity dilatation and noninfarcted myocardial hypertrophy (remodeling index at 21 days: no reperfusion, 2.67 +/- 0.15, n = 13; reperfusion after 1 to 2 hours, 2.20 +/- 0.15, n = 15, P = .035; reperfusion after 6 to 8 hours, 2.12 +/- 0.10, n = 9, P = .012). Histological examination revealed that reperfusion accelerated the clearance of residual dead myofibrils, suggesting an increase in the rate of healing, and increased the degree of myocytolysis but did not change the final degree of infarct healing, tissue density, or viable subepicardial cells.

CONCLUSIONS

Late reperfusion causes a permanent reduction in postinfarction expansion that is present even after complete infarct healing. The time after coronary occlusion in which reperfusion is of benefit in reducing subsequent expansion and remodeling is substantially longer than previously established. The mechanism by which late reperfusion limits expansion may involve changing the rate of healing and the nature of myocardial necrosis but does not involve preserving subepicardial cells.

Characterization of transmural and subendocardial infarction by typing and grading of ischemic lesions in autopsied human hearts

Two types of myocardial infarction, transmural and subendocardial, were macroscopically examined, and the gross and microscopic findings were correlated. The transmural type usually consisted of yellowish-brown coagulation necrosis in the center of an infarcted focus and coagulative myocytolysis at the marginal zone. The subendocardial type was characterized by coagulative myocytolysis throughout the entire focus. Wavy fiber and colliquative myocytolysis of non-specific ischemic lesions were seen only microscopically in both peripheral and subendocardial areas of infarcted foci. Coagulation necrosis was associated with obstructive thrombus formation in 79% of cases as a result of absolute ischemia in the transmural type. Coagulative myocytolysis was associated with obstruction by plaque hemorrhage in 27% of cases, and multivessel disease was frequently encountered in the subendocardial type due to insufficient blood supply. Based on histochemical and immunohistochemical examinations, the ischemic lesions were graded in descending order of coagulation necrosis, coagulative myocytolysis, wavy fiber, and colliquative myocytolysis. The close relation between coagulation necrosis and the transmural type as well as that of coagulative myocytolysis with the subendocardial type suggests two different pathogenetic mechanisms of transmural and subendocardial infarction.

Murine acinar pancreatitis preceding necrotizing myocarditis after Coxsackievirus B3 inoculation

Balb/C weanling mice were inoculated intraperitoneally with a myocarditic variant of coxsackie-virus B3, with the aim of characterizing more fully the cell damage induced in the heart as well as in other organs. During the first week postinfection (pi), all animals developed acinar pancreatitis, followed by focal myocarditis. In accordance with the increasing infectivity titers, such progressive histopathological changes correlated with local viral replication. From day 4 pi, acinar degeneration accompanied by diffuse inflammatory exudate was observed in the pancreas, followed by fatty tissue replacement by day 8. In the heart, focal necrosis rather than inflammatory reaction first appeared at 4 days pi and became widespread by 6-8 days pi. Necrotic foci usually presented calcium deposits, with absence of myofibrils in the affected fibers. The fact that both periodic acid Schiff (PAS) and Best carmine staining remained positive even after diastase treatment ruled out basophilic necrosis. In summary, the pancreas appeared to be the site of primary viral replication leading to viremia.

Effect of haloperidol decanoate on the cardiovascular system

Rapid speed electrocardiograms were recorded in 13 chronic schizophrenic patients before, and at regular intervals during a six-month trial of haloperidol decanoate. Measurements of conduction intervals in the EEG were carried out blind to patient and to assessment interval. No significant changes in heart rate; PR, QRS on QTc intervals; or T-wave height were found. Neither was there a significant change in the blood pressure. The findings confirm that haloperidol does not have clinically relevant cardiac effects when given in therapeutic doses to physically healthy individuals.

Diagnostic significance of myofibrillar degeneration of cardiocytes in forensic pathology

The incidence of myofibrillar degeneration (MFD) was studied in the following different forensic-pathological diagnostic groups of 25 cases each: acute morphine intoxication, acute carbon monoxide intoxication, hanging, strangulation by hand/ligature, drowning, acute hemorrhagic shock, lethal acute brain injury, explainable death of babies or infants and sudden infant death syndrome, together with 18 cases of intoxication with various drugs. The MFD was demonstrated by the Luxol-fast-blue reaction, with two types of phenomena being differentiated, namely cross-band lesions and diffuse staining. All diagnostic groups included cases of MFD of differing degrees. Cross-band lesions were observed in practically all cases of hanging, strangulation and acute hemorrhagic shock. Diffuse stain was noted particularly in cases of drowning and acute brain injury. The diagnostic significance is discussed.

Screening of myocardial contraction bands: a comparison between two histological staining methods

Two histological stains for demonstration of contraction bands (cb): Mallory's phosphotungstic acid hematoxylin (PTAH) and a modification of luxol fast blue (LFB) were compared. Microscopical sections from hearts from 60 autopsies were screened. The regional distribution of the cb lesions was also studied. It was found that PTAH showed cb more consistently than LFB. None of the stains were suitable for screening in the lowest magnification. In cases of cardiac death the cb were often extensive and scattered throughout the myocardium. In non-cardiac deaths with cb these were always discrete and seen only in one location which might be a means of differentiating lesions of pathogenetic importance from agonal ones.

Cardiac manifestation and blood catecholamine levels during succinylcholine-induced stress of malignant hyperthermia sensitive pigs

Fifteen crossbred pigs of Swedish Landrace and Yorkshire, about 6 months of age and susceptible to develop malignant hyperthermia (MH) when exposed to halothane, were subjected to stress provoked by the myorelaxant succinylcholine. The results were compared with those of 12 normal pigs. During the stress the halothane-sensitive (HS) pigs showed much higher levels of plasma noradrenaline and adrenaline and more severe ventricular arrhythmias than the controls. The degree of myocardial degeneration and necrosis being similar to catecholamine induced myocardial damage was significantly higher in the HS pigs than in the controls. The ultrastructural examination revealed three main types of changes in affected myocardial cells. One type of myocardial cell damage was characterized by various degree of hypercontraction, enlarged mitochondria with dense bodies and dilated sarcoplasmic reticulum. The other type showed mitochondria with tubular configuration whereas the third type of cell damage was characterized by almost normal mitochondria combined with a severe damage of the myofilaments. Three HS pigs which died within 30 min after stress showed signs of malignant hyperthermia. No signs of the disease were observed in the other 12 HS pigs.

Diabetic heart disease--Part II: The clinical and pathological spectrum

Diabetes mellitus is a significant condition, affecting major segments of all population groups studied. With the introduction of insulin and oral hypoglycemic therapy, together with better understanding of diet and weight control gained over the past half century, the primary causes of diabetic morbidity and mortality have shifted in varying proportions from metabolic derangements, infection, and renal insufficiency to different types of cardiovascular disease. Despite extensive clinical and laboratory research on the etiology, pathogenesis, and even the existence of cardiovascular disease associated with diabetes mellitus, however, considerable debate is still apparent in this field. Our purpose is to present an overview of the subject of diabetic heart disease, with a critical analysis of epidemiologic, clinical, and pathological data. Some of this material will be addressed from the perspective of research in this area over the past decade by one of us (SMF), particularly in experimental hypertensive and diabetic cardiomyopathy. However, overall, an attempt will be made to provide an objective and balanced analysis in order to answer the question: does diabetic heart disease exist?

Cardiac and neurological abnormalities in v-fps transgenic mice

Transgenic mice that widely express the v-fps protein-tyrosine kinase develop several independent pathological conditions, in addition to a high tumor incidence. v-fps expression and protein-tyrosine kinase activity in the heart were directly correlated with cardiac enlargement. This cardiomegaly was accompanied by severe myocardial and endocardial damage, which was concentrated in the left ventricular wall, and characterized by a progressive atrophy and necrosis of cardiac muscle fibers with concomitant fibrosis. This pathology was associated with congestive heart failure. Mice from five lines developed a marked trembling, correlated with expression of the v-fps transgene in the brain, and two lines showed a striking bilateral enlargement of the trigeminal nerves. Unlike tumor formation, these cardiac and neurological phenotypes were evident shortly after birth and showed 100% penetrance. The pleiotropic effects of the v-fps transgene suggest the involvement of protein-tyrosine kinases in mammalian neural development and cardiac function.

Identification of alpha 1-adrenergic receptors on sarcolemma from normal subjects and patients with idiopathic dilated cardiomyopathy: characteristics and linkage to GTP-binding protein

Discontinuous density sucrose gradient centrifugation was used to isolate membrane vesicles from the left ventricle of three normal subjects (one prospective organ donor and two traffic victims whose hearts were obtained 1 hour after death) and nine patients undergoing cardiac transplantation as a consequence of idiopathic dilated cardiomyopathy. Sarcolemma-enriched subcellular fractions, detected in the interface between 8.55% and 25% sucrose, were identified by the increased activity of Na+,K+-ATPase and by enrichment in beta-adrenergic receptor density. The density of beta-adrenergic receptors was lower in vesicles from diseased hearts (610 +/- 71 fmol/mg protein) than in vesicles from normal hearts (1,410 +/- 226 fmol/mg protein; p less than 0.01). alpha 1-Adrenergic receptors were identified in these membrane vesicles by [3H]prazosin binding. Specific binding of [3H]prazosin was about 50% of the total binding at 1 nM, and alpha 1-adrenergic binding sites were saturable at approximately 3 nM. Scatchard analysis revealed 58 +/- 5 fmol/mg protein (KD = 0.90 +/- 0.08 nM) in pathological hearts and 30 +/- 5 fmol/mg protein (KD = 0.90 +/- 0.03 nM) in normal hearts (p less than 0.01). The displacement curve of (-)-norepinephrine in membrane vesicles from normal hearts delineated one subpopulation of alpha 1-adrenergic receptors; the addition of 0.1 mM GTP did not cause right shift. In membrane vesicles from diseased heart, the displacement curve of (-)-norepinephrine disclosed two subpopulations of alpha 1-adrenergic receptors. A right shift that occurred after addition of GTP showed that in this case alpha 1-adrenergic receptors were functionally coupled with GTP-binding protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac damage in autologous bone marrow transplant patients: an autopsy study. Cardiotoxic pretreatment as a major risk factor

The myocardium was studied histologically at autopsy in seven patients who died 9-85 days (median 22 days) after autologous bone marrow or blood-derived stem-cell transplantation. Clinical investigations including echocardiography suggested normal cardiac function in all patients prior to transplantation. Myeloablation was performed by total body irradiation (1200-1560 cGy) and cyclophosphamide (200 mg/kg). Morphological findings were graded semi-quantitatively and correlated with previous and current therapy. Histological alterations did not correspond to the dosages of myeloablative therapy. However, cardiac failure, the primary cause of death in four patients, was associated with coagulative fiber necroses and contraction band necroses, which may be related to acute cyclophosphamide toxicity. In three of these patients high-dose cardiotoxic pretreatment with anthracyclines and mitoxantrone has been performed beyond the critical cardiotoxic level. High-dose pretreatment was correlated with histological hallmarks of anthracycline heart disease: marked chromatin clumping of myocardial cell nuclei (3/3 patients), occurrence of plurivesicular "adria" cells (3/3 patients), and diffuse interstitial myocardial fibrosis (2/3 patients). Our morphological observations indicate for the first time that pretreatment with anthracyclines and mitoxantrone may enhance cardiotoxicity of myeloablative therapy in bone marrow transplantation.

Cardiac lesions in sudden infant death syndrome

Sequential morphological changes as found in the hearts of 250 sudden infant death syndrome (SIDS) infants are described. Detailed examination of macroscopic and microscopic lesions reveal that all SIDS infants had identifiable lesions at the time of their death. The lesions can best be described as selective focal anoxic muscle fibre necrosis at chronologically different developmental stages. The extent of these lesions vary markedly from case to case, from a minimal muscle fibre eosinophilia through contraction band formation, myocytolysis, stromal condensation to scar formation. The morphological variations in the lesions amongst individual cases can be interpreted as relating to the time interval of the development of the lesions. The intramural and coronary arteries in some cases are also affected showing intimal hyperplasia. Although these sequential morphological aberrations are not specific and typical to SIDS infants only, they were present in all SIDS infants in this series.