Human Autopsy Hearts Research Articles

The autonomic nerves around the vein of Marshall: apostmortem study with clinical implications.

This study aims to analyze the vein of Marshall (VOM) in human autopsy hearts and its correlation with clinical data to elucidate the morphological substrates of atrial fibrillation (AF) and other cardiac diseases. Twenty-three adult autopsy hearts were studied, assessing autonomic nerves by immunohistochemistry with tyrosine hydroxylase (sympathetic nerves), choline acetyltransferase (parasympathetic nerves), growth-associated protein 43 (neural growth), and S100 (general neural marker) antibodies. Interstitial fibrosis was assessed by Masson trichrome staining. Measurements were conducted via morphometric software. The results were correlated with clinical data. Sympathetic innervation was abundant in all VOM-adjacent regions. Subjects with a history of AF, cardiovascular cause of death, and histologically verified myocardial infarction had increased sympathetic innervation and neural growth around the VOM at the mitral isthmus. Interstitial fibrosis increased with age and heart weight was associated with AF and cardiovascular cause of death. This study increases our understanding of the cardiac autonomic innervation in the VOM area in various diseases, offering implications for the development of new therapeutic approaches targeting the autonomic nervous system.

Histology, OCT, and Micro-CT Evaluation of Coronary Calcification Treated With Intravascular Lithotripsy: Atherosclerotic Cadaver Study

BackgroundAlthough intravascular lithotripsy (IVL) has been an emerging novel option to treat vascular calcification, the specific effects on histology have not been systematically examined. ObjectivesThe authors examined the histologic effects of IVL on coronary calcified lesions from human autopsy hearts and evaluated the diagnostic ability of optical coherence tomography (OCT) and micro-computed tomography (CT) to detect calcium fracture as identified by the gold standard histology. MethodsEight coronary lesions were treated with IVL, and 7 lesions were treated with 10 atm inflation using an IVL catheter balloon without lithotripsy pulses (plain old balloon angioplasty [POBA]). OCT and micro-CT imaging were performed before and after treatment, and the presence of calcium fracture was assessed. The frequency and size of fractures were measured and compared with the corresponding histology. ResultsAll 15 treated lesions were diagnosed as sheet calcium by histology. Histological evidence of calcium fracture was significantly greater in the IVL group compared with the POBA group (62.5% vs 0.0%; P = 0.01). Calcified lesions with fracture had a larger maximum arc degree of calcification (median 145.6 [IQR: 134.4-300.4] degrees vs 107.0 [IQR: 88.9-129.1] degrees; P = 0.01). Micro-CT and histology showed an excellent correlation for fracture depth (R2 = 0.83; P < 0.0001), whereas OCT showed less correlation (R2 = 0.37; P = 0.11). The depth of fractures measured by OCT were significantly shorter than with those measured by histology (0.49 [IQR: 0.29-0.77] mm vs 0.88 [IQR: 0.64-1.07] mm; P = 0.008). ConclusionsIVL demonstrated a histologically superior fracturing effect on coronary calcified lesions compared with POBA. OCT failed to identify the presence of some calcium fractures and underestimated the depth of fracture when compared with micro-CT.

Abstract 12487: Ex Vivo Assessments of Human Nodular Calcification: Optical Frequency Domain Imaging and Histopathology

Introduction: It has been reported that a nodular calcification is associated with a calcified nodule and the reappearance of in-stent failure after percutaneous coronary intervention. Hypothesis: This study evaluated characteristics of nodular calcification on optical frequency domain imaging (OFDI) image in comparison to histopathology. Methods: One hundred and seven matched OFDI and histopathological cross-sections from 13 coronary arteries of 5 human autopsy hearts were evaluated. In histopathological assessment, a nodular calcification was defined as a fragmented calcification with accumulated fibrin. In OFDI analysis, calcification arc, shape of luminal surface, lumen side shape of calcification, irregularity of lumen surface, and irregularity of calcification surface of lumen side were analyzed in each OFDI image. Results: There were 10 nodular calcifications and 97 non-nodular calcifications in histopathological slices. The calcification arc was significantly smaller in nodular calcification than in non-nodular calcification [89.5° (56.4-108) vs. 126° (82.0-190), p =0.02]. OFDI features of a nodular calcification were characterized by a convex shape of the luminal surface (90.0% in nodular calcifications vs. 6.2% in non-nodular calcifications, p &lt;0.01), a convex shape of calcification (90.0% vs 18.6%, p &lt;0.01), an irregular luminal surface (50.0% vs 0%, p &lt;0.01), and an irregular calcification surface of lumen side (60.0% vs 3.1%, p &lt;0.01). Conclusion: This study suggests that OFDI has a potential capability to distinguish between nodular calcification and non-nodular calcification based on angle of calcification, shape and irregularity of luminal surface and those of calcification.

Human Pulmonary Vein Myocardial Sleeve Autonomic Neural Density and Cardiovascular Mortality.

Myocardial sleeves around pulmonary veins (PVs) are highly innervated structures with heterogeneous morphological and electrophysiological characteristics. Autonomic nerve dysfunction in the myocardium may be associated with an increased risk of cardiovascular morbidity and mortality. This article studied autonomic neural remodeling in myocardial sleeves around PVs and atrial-PV ostia with immunohistochemical and morphometric methods with clinicopathological correlations. PVs were collected from 37 and atrial-PV ostia from 17 human autopsy hearts. Immunohistochemical analysis was performed using antibodies against tyrosine hydroxylase (TH), choline acetyltransferase (CHAT), and growth-associated protein 43 (GAP43). In the PV cohort, subjects with immediate cardiovascular cause of death had significantly decreased sympathetic nerve density in fibro-fatty tissue vs those with non-cardiovascular cause of death (1624.53 vs 2522.05 µm2/mm2, p=0.038). In the atrial-PV ostia cohort, parasympathetic nerve density in myocardial sleeves was significantly increased in subjects with underlying cardiovascular cause of death (19.48 µm2/mm2) than subjects with underlying non-cardiovascular cause of death with no parasympathetic nerves detected (p=0.034). Neural growth regionally varied in sympathetic nerves and was present in most of the parasympathetic nerves. Heterogeneous autonomic nerve distribution and growth around PVs and atrial-PV ostia might play a role in cardiovascular morbidity and mortality. No association in nerve density was found with atrial fibrillation.

Coronavirus Disease 2019 (COVID-19) and Cardiovascular Disease: A Viewpoint on the Potential Influence of Angiotensin-Converting Enzyme Inhibitors/Angiotensin Receptor Blockers on Onset and Severity of Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

Coronavirus Disease 2019 (COVID-19) and Cardiovascular Disease: A Viewpoint on the Potential Influence of Angiotensin-Converting Enzyme Inhibitors/Angiotensin Receptor Blockers on Onset and Severity of Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

Role of Cardiac Myocytes Heart Fatty Acid Binding Protein Depletion (H-FABP) in Early Myocardial Infarction in Human Heart (Autopsy Study).

BACKGROUND:Many immunohistochemical markers have been used in the postmortem detection of early myocardial infarction.AIM:In the present study we examined the role of Heart-type fatty acid binding protein (H-FABP), in the detection of early myocardial infarction.MATERIAL AND METHODS:We obtained samples from 40 human autopsy hearts with/without histopathological signs of ischemia.RESULTS:All cases of definite and probable myocardial infarction showed a well-defined area of H-FABP depletion. All of the control cases showed strong H-FABP expression, except two markedly autolysed myocardial samples that showed affected antigenicity.CONCLUSION:Thus, we suggest H-FABP as being one of the valuable tools facing the problem of postmortem detection of early myocardial infarction/ischemia, but not in autolysis.

Additive Value of Integrated Backscatter IVUS for Detection of Vulnerable Plaque by Optical Frequency Domain Imaging: An Ex Vivo Autopsy Study of Human Coronary Arteries

ObjectivesThis study sought to evaluate the diagnostic performance of optical frequency domain imaging (OFDI) for recognition of coronary plaque morphologies and to assess additive values of integrated backscatter intravascular ultrasound (IB-IVUS) in detection of vulnerable plaque. BackgroundPrecise diagnosis of coronary lesions susceptible to plaque rupture and thrombosis may serve to stratify the risk of future coronary events and to make decisions for appropriate treatment of choice. MethodsTwenty-seven coronary arteries from 14 human autopsy hearts were interrogated ex vivo by OFDI and IB-IVUS. Imaged segments were sectioned at 3 mm intervals where a total of 360 pairs of cross-sectional images coregistered to histology were investigated. ResultsOverall, OFDI could depict various plaque components and structures such as fibrous tissue, sheet and nodular calcification, lipid, cholesterol crystals, and healed plaque rupture. OFDI could detect 14 of 18 thin-cap fibroatheroma (TCFA), however, the diagnostic accuracy was not high (positive predictive value [PPV] = 60.9%, κ = 0.664; area under the curve [AUC]: 0.88) mainly because of signal interference from macrophages. Further, we defined IB-IVUS–derived TCFA by recursive partitioning analysis as: 1) cross-sectional % lipid area >65.1%; 2) % lipid area >32.3 but <65.1% with plaque area >10.5 mm2, where TCFA detection by IB-IVUS alone was marginal (PPV = 50.0%, κ = 0.545; AUC: 0.82). However, when IB-IVUS was combined with OFDI, all pseudo OFDI-derived TCFA (non-TCFA on histology) were excluded. Accordingly, PPV of TCFAs diagnosed by both OFDI and IB-IVUS was improved to 100.0% (κ = 0.704; AUC: 0.93). ConclusionsOFDI could recognize detailed morphologies of human coronary plaque. However, diagnostic accuracy of both OFDI alone and IB-IVUS alone to identify TCFA is limited. Combination of IB-IVUS with OFDI improved the accuracy for TCFA detection, suggesting hybrid imaging or further development of novel devices will be required to identify coronary lesions responsible for future events.

Telocytes in human epicardium

The existence of the epicardial telocytes was previously documented by immunohistochemistry (IHC) or immunofluorescence. We have also demonstrated recently that telocytes are present in mice epicardium, within the cardiac stem-cell niches, and, possibly, they are acting as nurse cells for the cardiomyocyte progenitors. The rationale of this study was to show that telocytes do exist in human (sub)epicardium, too. Human autopsy hearts from 10 adults and 15 foetuses were used for conventional IHC for c-kit/CD117, CD34, vimentin, S-100, τ, Neurokinin 1, as well as using laser confocal microscopy. Tissue samples obtained by surgical biopsies from 10 adults were studied by digital transmission electron microscopy (TEM). Double immunolabelling for c-kit/CD34 and, for c-kit/vimentin suggests that in human beings, epicardial telocytes share similar immunophenotype features with myocardial telocytes. The presence of the telocytes in human epicardium is shown by TEM. Epicardial telocytes, like any of the telocytes are defined by telopodes, their cell prolongations, which are very long (several tens of μm), very thin (0.1–0.2 μm, below the resolving power of light microscopy) and with moniliform configuration. The interconnected epicardial telocytes create a 3D cellular network, connected with the 3D network of myocardial telocytes. TEM documented that telocytes release shed microvesicles or exocytotic multivesicular bodies in the intercellular space. The human epicardial telocytes have similar phenotype (TEM and IHC) with telocytes located among human working cardiomyocyte. It remains to be established the role(s) of telocytes in cardiac renewing/repair/regeneration processes, and also the pathological aspects induced by their ‘functional inhibition’, or by their variation in number. We consider telocytes as a real candidate for future developments of autologous cell-based therapy in heart diseases.

Left atrial myocardial extension onto pulmonary veins in humans: anatomic observations relevant for atrial arrhythmias.

Electrophysiologic studies have shown that spontaneous initiation of atrial fibrillation (AF) by ectopic beats may originate from within pulmonary veins. The extensions of left atrial myocardium are considered to play a role, but there is little detailed anatomic information available, particularly in humans. Thirty-nine human autopsy hearts were studied; 22 with AF and 17 without atrial arrhythmias. The muscle fiber arrangement of the left atrial wall and pulmonary veins was dissected. In 18 hearts, myocardial sleeves were studied microscopically; in five hearts, three-dimensional reconstruction of the fiber arrangement in the myocardial sleeves was performed. Of 99 pulmonary veins examined, 96 contained a myocardial sleeve. The length of the sleeves was largest in the superior pulmonary veins (P < 0.01). There were no statistically significant differences between uniform and nonuniform muscle fiber arrangements. Microscopic evaluation revealed myocardial sleeves positioned on the adventitial side of the pulmonary vein, separated from the muscular media by a fibrofatty tissue plane. The most distal zone of the myocardial sleeves showed increasing fibrosis with encapsulation of small groups of myocardial cells and eventually with total disappearance of atrophic cells within fibrous tissue. Node-like structures were not encountered. There was no relationship with presence or absence of AF. The observation that the peripheral zones of myocardial sleeves are associated with increasing connective tissue deposition between myocardial muscle groups suggests a degenerative change that, from the histologic viewpoint, fits with progressive ischemia. These changes could provide a basis for microreentry and, hence, for atrial arrhythmias.

Cytometric analysis of ventricular myocyte nuclei in idiopathic dilated cardiomyopathy: a tool for evaluation of disease progression?

The progression of idiopathic dilated cardiomyopathy (IDC) is governed by factors that remain obscure. The disease pathway toward cell degeneration or death results in irreversible myocyte change including nuclear cytometric alterations which may be evaluable and ultimately correlated with other measures of disease evolution. Using a novel image cytometry system, we analysed differences in ventricular myocyte nuclear morphology and DNA content and distribution in right and left ventricular free wall myocardium and in ventricular septal myocardium from 11 normal and 13 IDC human autopsy hearts. Nine morphological features of IDC myocyte nuclei differed significantly (P < 0.001) from normal. These were used to establish a classification matrix and cytometry-based assessment and allowed correct categorization of left and right ventricular and ventricular septal myocyte nuclei in concordance with their respective pathological diagnosis (i.e. normal or IDC) 71%, 81% and 77% of the time. Additionally, four photometric features were significantly different (P < 0.005) in IDC versus normal hearts, as were three discrete texture features (P < 0.001). Thus, the spectrum of myocyte nuclei seen in IDC have highly characteristic and measurable morphologic, photometric and texture features. Our findings indicate the potential value of cytometry in the classification of myocytes with regards to a disease continuum and suggest its applicability in both clinical and experimental studies.

Variations in the papillary muscles of the normal mitral valve and their surgical relevance.

A mid-mitral plane passing through the middle of the aortic and mural leaflets divides the chordopapillary support of the mitral valve into anterolateral and posteromedial halves. The papillary muscles of the mitral valve were studied in 100 human autopsy hearts collected at random. The anterolateral papillary support had 1 belly in 67 hearts, 2 in 27, 3 in 4, 4 in 1, and 5 in 1 heart. Likewise, the posteromedial papillary support had 1 muscle belly in 50 hearts, 2 in 36, 3 in 11, and 4 in 3. The single papillary muscles were conical, mammillated, flat topped, grooved, stepped, wavy, arched, sloped or saucerized. When there were two bellies they presented a two tiered, interlinked, parallel, arched, V, Y, or H configuration. Three papillary muscles formed a parallel, interlinked or arched arrangement; or two bellies were interlinked or formed a two tiered arrangement with the third belly separate. When four or five bellies existed, they were parallel or interlinked. In the anterolateral and posteromedial group, the papillary muscle bellies were mostly intraluminal in 14% and 11%, mostly intraluminal with the tip anchored in 19% and 28%, equally sessile and intraluminal in 54.5% and 41.5%, mostly sessile in 12.5% and 19.5%, respectively. In the anterolateral group 19% of papillary muscle bellies arose from the upper third of the ventricle, 79.5% from middle third, and 1.5% from lower third. The corresponding figures for posteromedial group are 6%, 92.5%, and 1.5%, respectively. Four to 22 chordae originated from the anterolateral papillary group, ending in 14 to 72 chordal insertions into the corresponding half of the valve. Likewise, 2 to 18 chordae arose from the posteromedial papillary group ended in 12 to 80 leaflet insertions. The chordae in each group are best considered in toto as a fan. The configuration of the fan is unique in each heart. Imaging techniques need to be refined to outline these variations more precisely. The relevance of chordopapillary variations in rheumatic heart disease, reparative procedures, papillary muscle dysfunction, mitral valve prolapse, mitral valve replacement, and use of mitral valve homograft for mitral/tricuspid replacement is discussed.

Intracardiac Ultrasound Imaging During Transseptal Catheterization

The purpose of this study was to assess the feasibility of using small 12.5- or 20-MHz intracardiac ultrasound catheters to image the fossa ovalis and guide transseptal catheterization. The study was performed in three phases. First, in vitro imaging of human autopsy hearts was performed to define the intracardiac ultrasound appearance of the fossa ovalis and transseptal apparatus. Subsequently, the optimum approach for imaging the fossa ovalis in vivo was established in 30 patients. Finally, intracardiac ultrasound imaging was performed during transseptal catheterization of 10 patients undergoing percutaneous mitral commissurotomy. Intracardiac ultrasound imaging was performed with a 12.5- or 20-MHz single-element mechanical device in which a central imaging core is rotated within a 6F polyethylene sheath. In both in vitro and in vivo studies, the fossa ovalis was easily identifiable as a thin membranous region surrounded by the thicker muscular portion of the interatrial septum. Initial in vivo studies established venous access by the femoral route to be superior to the internal jugular approach for catheter introduction. Studies performed during transseptal catheterization established the utility of using the fluoroscopic image of the catheter adjacent to the fossa ovalis to generate a guiding shot for positioning the transseptal apparatus. In addition, distention of the fossa prior to needle perforation could be demonstrated. However, since it was often difficult to track the tip of the needle, actual puncture of the fossa was rarely demonstrated. Intravascular ultrasound imaging can precisely locate the fossa ovalis in virtually all subjects. It therefore may assist transseptal catheterization.

Magnetic resonance imaging of chronic myocardial infarcts in formalin-fixed human autopsy hearts.

In post-myocardial infarction patients, three-dimensional structure of the infarct as well as infarct size are likely to be important factors affecting mortality, cardiac function, and arrhythmias. Current morphological methods for determining three-dimensional infarct structure in autopsied hearts are inexact and time consuming. The cardiac magnetic resonance imaging techniques used in living patients have shown potential in determining infarct size and structure but have limited resolution for morphometric postmortem studies. The recent development of magnetic resonance microscopy raises the possibility that three-dimensional infarct structure can be quantified at microscopic levels in autopsied hearts. The purpose of this study was to determine the ability of magnetic resonance imaging at different spatial resolutions to differentiate infarcted from noninfarcted myocardium. Magnetic resonance imaging was performed at 2.0 T on cross sections taken from 10 autopsied hearts containing old myocardial infarcts. T1 was derived from six images with repetition times (TRs) for each image ranging from 100 to 3200 milliseconds. T2 was derived from multi-echo images with echo times (TEs) ranging from 10 to 60 milliseconds. Resolution was approximately 400 x 400 microns in 2-mm-thick slices. Sites of infarcted and noninfarcted tissue were identified from histological sections taken from each slice, and the T1 and T2 values of these sites were obtained. Microscopic images were acquired with voxels of 100 x 100 x 625 microns, representing tissue volumes more than 1000-fold smaller than conventional clinical images. In all cases, T1 of infarcted tissue (459 +/- 266 milliseconds, mean +/- SD) was greater than that of noninfarcted tissue (272 +/- 163 milliseconds). Also, in all cases, T2 of infarcted tissue (49 +/- 14 milliseconds) was greater than that of noninfarcted tissue (35 +/- 8 milliseconds). T1 and T2 values for infarcted tissue are significantly different from those of noninfarcted tissue (P < .001). Based on these findings, it should be possible to develop techniques to perform three-dimensional imaging and quantitation of infarcts with a resolution of 400 microns or less. When volumetric three-dimensional imaging was performed using a T1-weighted sequence, the resulting 256(3) arrays supported isotropic resolution at 400 microns (voxel volume, 0.064 mm3). Subsequent volume rendering using a compositing algorithm clearly shows the infarcted areas in three dimensions. The techniques demonstrate the potential for quantitative three-dimensional cardiac morphometry using magnetic resonance imaging.

An Angiographic Study of Intracardiac Coronary Arteries from Human Autopsy Hearts: Their Clinicopathologic Significance and Characterization During Transmural Myocardial Infarction

In this study of human autopsy hearts, coronary arteries were divided by morphologic criteria into classes A (branching-type) and B (straight-type) arteries. Infarcted hearts and normal hearts were investigated mainly by means of coronary angiography, as well as by gross and histologic examinations. Transmural myocardial infarction originated in the inner half of the myocardial layer, which was predominantly supplied by class A arteries, followed by gradual extension to the outer layer. The early infarcted focus revealed an angiographically avascular state. This may have been the result of shrinkage of the peripheral branches of class A arteries due to increased extravascular resistance rather than to arteriolar obstruction by small thrombi and/or leukocyte plugs. By contrast, class B arteries remained patent and were almost entirely free from such phenomena. They usually penetrated the infarcted focus to drain into the papillary muscles and trabeculae carnae. As the process of myocardial infarction progressed, various patterns of vascular reactions corresponding to the healing phase were demonstrated by these branches within the infarcted foci. The passive response of class A arteries during acute ischemia characterized the early myocardial lesion. Subsequently, neovascularization from the surviving class B arteries in the infarcted focus occurred as a part of the formation of granulation tissue. Newly formed small arteries from class A arteries also participated in this reaction at the marginal area of the lesion. These well-coordinated vascular reactions revealed in greater detail the initiation and progression of the healing process and were reflective of the clinical prognosis.

Ventriculocoronary connections in hypoplastic right heart syndrome: Autopsy serial section study of six cases

Myocardial sinusoids communicating with the coronary systems occur in pulmonary atresia with intact ventricular septum. To test the hypothesis that the extent of ventriculocoronary connections correlates with the degree of right ventricular outflow obstruction as evidenced by clinical, angiographic and gross anatomic findings, a serial section study of six human autopsy hearts representing a spectrum of hypoplastic right heart was undertaken. Slides were evaluated for the presence and extent of ventriculocoronary connections, associated developmental abnormalities and secondary changes in the ventricular walls.Whereas extensive blind-ended deep sinusoids were a feature of all five cases with unrelieved obstruction, ventriculocoronary connections were identified in three. Changes that suggested ongoing remodeling provide new evidence for the postnatal temporal evolution of these anomalous communications. The regional distribution of myofiber disarray in hypoplastic right heart supports the concept that vascularization parallels myocardial organization in the developing human heart.

Comparison of contrast X-ray biplane cineangiography and technetium-99m radionuclide scans for measurement of ventricular volumes in human autopsy hearts

The area-length method is widely used in the determination of left ventricular volume. Although previous studies have reported that this technique overestimates true volume (TV), it is unknown whether this overestimation is the same at different volumes. In the present study, with the use of 10 postmortem human hearts, left ventricular volumes were determined by contrast x-ray biplane cine ventriculography (LVA), biplane radionuclide (LVR), and absolute-counts (LVC) technetium scans, and the results were correlated with TV. LVA correlated well with TV ( r = 0.98). LVR correlated well with TV ( r = 0.97), and LVR also correlated well with LVA ( r = 0.96). Both area-length techniques (LVA and LVR) resulted in overestimation of TV with an upward shift of the regression line of 30.4ml ± 3.8 (SEM) for LVA and 28.5 ± 4.4 for LVR. The percentage of overestimation error was significantly greater at smaller left ventricular volumes (error = 33% at TV = 30ml and 10% at TV = 100ml, p < 0.001). LVC correlated well with TV ( r = 0.99), TVA, and LVR but underestimated TV. Thus left ventricular volumes can be reliably obtained from LVR and LVA by means of the area-length method and from LVC. When the area-length method is utilized, the percentage of error in the determination of left ventricular volume is proportional to 1 TV .