Morphological and functional significance of findings in unstable atherothrombotic plaque underlying acute coronary syndromes: a review.
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Angina, Unstable↗
Biomedical subjects
G Baroldi
Publications and source records attributed to G Baroldi.
[About inflammation and atherosclerosis].
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Arteriosclerosis↗
Lysosomal glycogen storage with normal acid maltase: a familial study with successful heart transplant.
Lysosomal glycogen storage in muscle with normal acid maltase activity is a rare inherited condition characterized by cardiomyopathy, mental retardation and mild myopathy in males, but generally only cardiomyopathy in females. Three cases (index case, his sister and her son) are described in a family with at least two other affected members. The index case underwent a successful heart transplant. The sister has cardiac involvement, myopathic changes and mental impairment--to our knowledge the first report of multisystem involvement in a female. We propose that skeletal muscle should be examined in young patients with hypertrophic cardiomyopathy. Furthermore, female relatives of males with the disease should be investigated for cardiomyopathy; they would be excellent candidates for life-saving heart transplant, since myopathy and mental retardation, if clinically evident, are mild.
Adult↗
[The contribution of pathology sections to the Italian Heart Transplant Project in the first 5 years of its activities (1985-1990)].
All the transplantation units within the Italian Heart Transplantation Project are supported by a section of pathology, devoted to the study of the recipient's heart, to patient monitoring by means of a schedule of endomyocardial biopsies, and, if that was the case, to examine the donor's heart and to analyse the causes of death. When successes and failures of the first five years of the Project's activity are weighed up, good results are observed: of the 847 operations performed (orthotopic, heterotopic and heart-lung transplants, and re-transplants) an actuarial survival rate of 77% at 5 years has been achieved. The sections of pathology believe to have contributed significantly to these results, examining as many as 10,446 endomyocardial biopsies. The indications for transplantation were: dilated cardiomyopathy (48.5%); ischemic (35.3%); valvular (5.9%) and congenital (2.4%) heart disease; hypertrophic cardiomyopathy (2.2%); endocardial fibroelastosis (1.7%); restrictive cardiomyopathy (1.4%); anthracycline cardiotoxicity (0.8%); myocarditis (0.8%); cardiac tumours (0.5%) and arrhythmogenic cardiomyopathy (0.2%). Distribution of recipients by sex and age varied according to the indications for transplantation: males were more common among the patients transplanted for ischemic (97%) and valvular (84%) heart disease, as well as for dilated (82%) and hypertrophic (78%) cardiomyopathy, whereas the opposite was true for endocardial fibroelastosis (males constituting 21%) and cardiac tumours (25%). Mean age at transplantation ranged from 49 years (ischemic heart disease) to 6 years (endocardial fibroelastosis). In the follow-up period, a 17.5% death rate was recorded; the main causes of death were the early failure of the transplanted heart (27 pts), postoperative complications (16), hyperacute rejection (4), acute rejection (18), infections (the singular most frequent cause of death, 35 pts), the proliferative endoarteritis of coronary branches (the so-called chronic rejection, that caused 21 deaths and required 14 re-transplants) and the development of neoplasms (11). The actuarial survival curve drops to 89% after the first postoperative month, abates to 82% at the end of the first year, and progressively decreases to 77% at the end of the fifth follow-up year. Rejection monitoring required an average number of 12.5 endomyocardial biopsies per recipient, and allowed 1.7 rejection episodes per patient to be diagnosed. The fewer were the rejection episodes occurring in a unit, the higher was the percentage of deaths due to infections.(ABSTRACT TRUNCATED AT 400 WORDS)
Age Factors↗
Phenotype of intramyocardial leukocytic infiltrates in acquired immunodeficiency syndrome (AIDS): a postmortem immunohistochemical study in 34 consecutive cases.
In 34 hearts, obtained at autopsy in consecutive AIDS cases, leukocytic phenotype and presence of viral antigens were investigated in paraffin-embedded (34 cases) and frozen myocardial sections (10 cases) by different monoclonal antibodies. The total frequency of focal lymphocytic infiltrates with and without myocell necrosis was 26.4 and 32.3%, respectively. In six control cases (HIV-negative i.v. drug abusers dying from acute fulminating hepatitis), these infiltrates were absent. In AIDS patients, the number of infiltrative foci per section, their wall distribution (subendocardial, middle layer, subepicardial), number of leukocytes per focus, and cell phenotype (prevalence of CD8+ suppressor/cytotoxic T-lymphocytes with CD4/CD8 ratio of 0.6 +/- 0.09 SE, absence of B-cells and granulocytes) were similar in cases with and without myocell necrosis. Significant differences were not observed between homosexual and i.v. drug abuser patients. In inflammatory foci associated with myocell necrosis CD45+/CD68+ monocytes prevailed, as a possible manifestation of nonspecific reparative process. In addition, in both AIDS patients and HIV-negative drug abusers, a population of CD68+ dendritic monocytes (histiocytes) characterized by a restricted CD45 expression (PanLeu-/9.4+) was found dispersed in the interstitium, with a significant higher frequency in the subendocardial layer. Histologic evidences of myocardial virus infections were not observed. Cytomegalovirus (CMV) antigens, however, were found in frozen sections of five of the six cases with lymphocytic infiltrates, supporting the view that this virus can be one of the possible causes of myocarditis in AIDS. Moreover, in two of these CMV-positive cases, a concomitant expression of HIV1 antigens in isolated intramyocardial leukocytes was also observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Acquired Immunodeficiency Syndrome↗
Coronary occlusion: cause or consequence of acute myocardial infarction?
A 45-year-old man with unstable angina developed persistent ECG changes of myocardial ischemia during coronary angiography. Occlusion of the left anterior descending branch (LAD) was documented 20 minutes after these changes. Intracoronary nitrate, Ca antagonist, urokinase, removal by percutaneous transluminal coronary angioplasty (PTCA) of atherosclerotic obstructions, and emergency bypass surgery failed to restore myocardial perfusion. Only short periods of reflow were obtained by urokinase and PTCA. The repeated coronary injections demonstrated a progressive disappearance of the left anterior descending artery (LAD) starting from the distal portion and progressing retrogradely up to the origin of the vessel. The patient developed a transmural anterolateral myocardial infarction and 12 months later underwent cardiac transplantation for untractable failure. His heart was examined and the infarct confirmed. Analysis of this case suggests that coronary occlusion in acute myocardial infarction can be an event secondary to increased intramyocardial resistance rather than the cause of reduced coronary blood flow in subepicardial coronary arteries.
Angioplasty, Balloon, Coronary↗
Coronary arterial wall and atherosclerosis in youth (1-20 years): a histologic study in a northern Italian population.
Based on the working hypothesis that coronary atherosclerosis begins in childhood, a histologic study was carried out on the subepicardial coronary arterial tree of 100 young persons (1-20 years), who had died from causes unrelated to the cardiovascular system. These subjects were natives of a well-defined geographic area in northern Italy, namely the region of Veneto. Intimal proliferations (musculo-elastic and fibro-elastic layers) were observed in 95.3% of the coronary arterial segments in the age group between one and five years. The more distal the coronary segments examined, the lesser was the intimal thickening. Raised mature fibrous plaques were detected in 23 segments from 15 patients (2 from subjects aged between six and 10 years; 4 between 11 and 15 years, and 9 between 16 and 20 years). Single vessel disease was present in 9, double vessel disease in 4 and triple vessel disease in 2 cases. The site most involved by plaques was the proximal part of the left anterior descending coronary artery. Only one plaque was of sufficient dimensions to be considered stenotic (50% luminal reduction). Plaques were rarely sudanophilic, and all seemed to arise in relation to previous intimal thickening. No qualitative nor quantitative sexual differences were observed. These data give rise to much concern, and one consistent with a recently observed occurrence of sudden coronary death in young people from the same geographic area.
Adolescent↗
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)
Adult↗
[Anatomic type of cardiac damage caused by antitumor drugs and radiation].
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Antineoplastic Agents↗
The usefulness of the resting electrocardiogram for characterizing acute Chagas' heart disease in the rat.
The present experiment was undertaken to characterize the resting electrocardiogram of rats in the acute stage of experimental T. cruzi infection. One-hundred-and-eighty-seven newly-weaned male albino rats were infected intraperitoneally with 1000 parasites/g body weight. Thirty-two similar but non-infected rats served as controls. Groups of eight randomly chosen rats were killed on day 8, and on days 15, 18, 22, 25 and 29 after infection. Groups of 8 control rats were killed on days 8, 15 and 22. Electrocardiographic changes were observed in 25 of 48 (52%) infected rats. P wave abnormalities indicating atrial chamber dilatation, QRS axis deviation, QRS complex changes compatible with left ventricular hypertrophy or myocardial damage, increased PR interval and ventricular repolarization alteration were detected in 24, 27, 18, 10, and 6% of infected rats, respectively. A mononuclear cell infiltrate and pseudocysts of amastigote forms of T. cruzi were found in 91, and 56% of infected animals, respectively. The sensitivity and the positive predictive value of the electrocardiographic changes were 66, 91, and 96%, respectively. Thus, the resting electrocardiogram is a reliable method for detecting myocardial lesions in the rat with acute Chagas' heart disease.
Animals↗
Focal lymphocytic myocarditis in acquired immunodeficiency syndrome (AIDS): a correlative morphologic and clinical study in 26 consecutive fatal cases.
In 26 consecutive cases with acquired immunodeficiency syndrome (AIDS) the main cardiac findings were Kaposi's sarcoma in 2 cases, microfocal myocardial abscess in 1, subendocardial infarct necrosis in 2, contraction band necrosis in 13, lymphocytic myocarditis in 9, intramyocardial lymphocytic infiltrates without myocell necrosis in 7 and epicardial lymphocytic infiltrates in 4. No patient had congestive heart failure. However, two-dimensional echocardiography performed in eight patients demonstrated functional abnormalities in six (fractional shortening ranging from 18 to 30%, globular shape, hypokinesia, mild ventricular dilation). Four of these six patients had lymphocytic myocarditis and two had lymphocytic infiltrates in the myocardium and epicardium without myocell necrosis. No lymphocytic infiltrates were seen in the two cases with a normal echocardiogram. Quantitative analysis indicated that involvement of the heart by lymphocytic myocarditis is inadequate in itself to explain dysfunction. It remains to be established 1) whether lymphocytic myocarditis is a possible indication of a more widespread molecular disorder, and 2) what its eventual relation with dilated cardiomyopathy will be.
Acquired Immunodeficiency Syndrome↗
Echocardiography detects myocardial damage in AIDS: prospective study in 102 patients.
Few data are available about cardiac involvement in AIDS. We examined 102 consecutive patients with AIDS diagnosed clinically and serologically (Walter Reed Stage 5 and 6), by means of TM and cross-sectional echocardiography with the aim of detecting cardiac abnormalities. None of the patients had overt clinical signs of heart failure. Fifty-five (54%) patients showed persistent tachycardia, diminished left ventricular (LV) wall thickness (mean 7.6 +/- 0.2 mm) and decreased percentage LV fractional shortening (27 +/- 5). In 42 (41%) there was a globular and poorly contracting LV. Thirty-nine (38%) patients had pericardial effusion which was moderate in 30 and small in nine. In four patients, valvular endocarditic vegetation was shown--on the tricuspid valve in three, on the aortic valve in one: all of them were drug addicts; in three (2.9%) patients a cardiac mass was found which proved to be a localization of Kaposi's sarcoma in two. Twenty-five (24.5%) patients died; necropsy showed cardiac chamber dilation, and thin LV walls in 18. On microscopic examination, myocardial fibrosis and lymphocyte infiltration with cell necrosis were observed. We conclude that cardiac abnormalities are common in AIDS. Impairment in LV contractility as assessed from fractional shortening appears to be the most common echocardiographic finding, followed by LV wall thinning, pericardial effusion and eventually by LV cavity dilation. This evolution is suggestive of myocardial damage and supports the hypothesis that dilated cardiomyopathy may be a cardiac complication of AIDS.
Acquired Immunodeficiency Syndrome↗
Anatomy and quantification of myocardial cell death.
Irreversible damage of the myocardial cells may show different morphologic aspects in relation to the type of dysfunction of their contraction-relaxation cycle. Attenuation of the muscle fibers with elongation of the sarcomeres and nuclei are the earliest modifications (systolic paradoxical bulging and stretching by the intraventricular pressure) when the myocells stop their function in irreversible relaxation. This 'atonic' death is pathognomonic of myocardial infarction (infarct or coagulation necrosis) and the lesion evolves with typical structural changes. An opposite and entirely different morphologic pattern is seen in the 'tetanic' death in which the myocardial cells arrest in irreversible contraction (coagulative myocytolysis or contraction band necrosis). Segmental (paradiscal bands) or pancellular hypercontraction with extreme shortening of the sarcomeres and subsequent myofibrillar rhexis alternated with irregular cross band formations (holocytic bands) are characteristic of this necrosis seen in numerous human and experimental conditions and specific of catecholamine toxicity. The third type of damage is observed in low output syndromes in which increasing edematous vacuolization and disappearance of the myofibrils (colliquative myocytolysis) are the main structural alterations. They are suggestive of progressive functional reduction leading to dilatative insufficiency ('failing' death). These clear-cut morphofunctional patterns indicate distinctive biochemical impairments and pathogenesis. In particular their frequent presence in and possible association with the different aspects of the ischemic heart disease presuppose other non-ischemic mechanisms responsible for complications and death in this modern epidemic.
Animals↗
Correlation of morphological variables in the coronary atherosclerotic plaque with clinical patterns of ischemic heart disease.
The frequency and severity of "morphological" variables (fibrosis, proteoglycan accumulation, atheroma, intimal vascularization, calcification, acute intimal hemorrhage, and both adventitial and intimal lymphoplasmacellular infiltrates) in atherosclerotic plaques were related to plaque type, percentage of lumen reduction, plaque length, and intimal and medial thickness in 3,640 coronary artery sections sampled at the site of maximal lumen reduction in 8 selected segments from 100 cases of acute myocardial infarct, 50 of chronic angina, 208 of unexpected sudden coronary death with or without prodromata, and from 97 normal subjects dying accidentally. Morphological variables were occasionally observed in 1,519 sections with no lumen reduction. They were found only in sections from ischemic patients. With increasing luminal stenosis and intimal thickness, progression of the coronary plaque seemed to start as a fibrous change followed by proteoglycan accumulation in the deeper portion of the fibrous intima. Proteoglycan deposits appeared as a recurrent phenomenon. In them, atheroma or calcification develop. Intimal hemorrhage was a less frequent variable. It was found mainly in a vessel supplying an infarcted area. Lymphoplasmacellular inflammation correlated mainly with proteoglycan accumulation and atheroma, both showing a parallel increase with increasing intimal thickness and lumen reduction. No correlation was found between plaque variables and sex, age, heart weight, and infarct size. Significant variations in the distribution of plaque variables were observed among hearts of patients in the ischemic groups and between them and controls. In particular, inflammatory reaction was significantly more frequent and severe in ischemic groups than in controls, independent of the degree of coronary stenosis. Coagulative myocytolysis (contraction band necrosis), found in the majority of ischemic patients, correlated with the inflammatory reaction in supplying vessels. A peculiar tropism of mononuclear cell infiltrates for adventitial nerve structures was found. As a result, we question whether this inflammation may trigger coronary spasm and/or coagulative myocytolysis ("active" plaque vs "inactive" plaque).
Arteries↗
Organization of heart transplantation in Italy.
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Heart Transplantation↗
Ischemic heart disease: clinical and pathological mismatch.
Disagreements between dynamic and postmortem morphology arise mainly from different imaging and selection of study population. The high frequency of severe and multivessel atherosclerotic stenosis in non cardiac patients and healthy subjects dying accidentally questions the direct cause-effect relationship between stenosis and ischemic heart disease; supports the view the dramatically enlarged collaterals always found in this condition may have an adequate compensatory role; and suggests the ineffectiveness of occlusion at the site of severe stenosis already bypassed by collaterals. The degree and number of severe stenoses in ischemic heart disease do not predict onset, course, complications, infarct size or death. On the other hand, the presence in this disease of three different types of morpho-functional myocardial damage indicate that different pathogenic mechanisms exist. Complications and death appear related more to metabolic disorders linked with adrenergic unbalance than to ischemia and subsequent expansion of primary infarct necrosis. Finally, postmortem findings show that lympho-plasmacellular inflammation of coronary atherosclerotic plaques is significantly more frequent (100% acute infarct, 88% chronic ischemia, 83% sudden coronary death, 64% healthy controls), severe and diffuse in all plaques in single patients compared to controls. Its preferential location around pericoronary nerves suggests the working hypothesis that it may be the cause of spasm and/or regional alterations of cardiac contractility with extravascular compression of the intramyocardial vasculature. These functional mechanisms could explain the cineangio imaging of coronary cut off rather than thrombus.
Angina Pectoris↗
Medial hyperplasia obliterans of the intramural coronary arterial vessels.
Primitive structural changes of the tunica media of the intramural coronary small arterial branches have been observed in 52 per cent of 208 unexpected sudden coronary death cases and in 78 per cent of 97 normal subjects dying by accident. These changes consisted in hyperplasia and hypertrophy of the smooth muscle cells with longitudinal and oblique bundle formation, dramatic thickening of the media and fibrous replacement with lumen reduction. No aneurysms, inflammatory reaction or abnormal depositions have been observed. This process, defined as "Medial hyperplasia obliterans", showed a preferential location in the anterior papillary muscles, columnae carneae, superior interventricular septum. When present the number of "hyperplastic" vessels ranged from one to a maximum of forty-four per section. No relation was found with acute or chronic myocardial damage, heart weight, sex and age and sudden death. From the present data these medial structural changes and their aging appear to be a physiological response of the arterial wall to functional factors linked with the regional myocardial contraction. The correct recognition of this overlooked pattern seems important to avoid pathogenic misinterpretations and erroneous diagnosis of small vessel disease in case of endomyocardial biopsy.
Coronary Vessels↗
Experimental catecholamine-induced myocardial necrosis. II. Temporal development of isoproterenol-induced contraction band lesions correlated with ECG, hemodynamic and biochemical changes.
Catecholamines have been shown to produce irreversible contraction band lesions of myocardial cells. However, little is known about the temporal appearance and correlation of the acute form of coagulative myocytolysis with ECG, hemodynamic and biochemical parameters. Groups of adult mongrel dogs were anesthetized with sodium pentobarbital, infused continuously with isoproterenol (2.5 micrograms/kg/min) and killed after periods of 0, 5, 15, 30, or 60 min. There were two predominant myocardial patterns: 'paradiscal' and 'holocytic' contraction band lesions. Either type of lesion was non-existent or rare in the control hearts. The small 'paradiscal' contraction band lesions were present as early as 5 min of isoproterenol infusion, particularly in the inner myocardial layer. The large 'holocytic' contraction band lesions were present by 15 min, however, they were not produced in any significant numbers before 30 min. Both types of contraction band lesions continued to accumulate up to 60 min. ST segment depression was the predominant ECG change. This occurred as early as 5 min when heart rate, blood pressure and dP/dt values had also significantly changed. The high-energy phosphates, phosphocreatine and ATP, started declining as early as 5 min. Furthermore, these phosphates and lactate were distributed in transmural gradients across the left ventricular wall with the greatest change in the endocardial third. This was also the site of the largest accumulation of each type of contraction band lesion. While the lesions correlated with certain biochemical and hemodynamic changes, the underlying pathophysiology is more complex than ischemia or high-energy phosphate depletion alone.
Adenosine Triphosphate↗