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Camman M, Joanne P, Agbulut O, Hélary C. 3D models of dilated cardiomyopathy: Shaping the chemical, physical and topographical properties of biomaterials to mimic the cardiac extracellular matrix. Bioact Mater 2022; 7:275-291. [PMID: 34466733 PMCID: PMC8379361 DOI: 10.1016/j.bioactmat.2021.05.040] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/21/2021] [Accepted: 05/21/2021] [Indexed: 12/12/2022] Open
Abstract
The pathophysiology of dilated cardiomyopathy (DCM), one major cause of heart failure, is characterized by the dilation of the heart but remains poorly understood because of the lack of adequate in vitro models. Current 2D models do not allow for the 3D organotypic organization of cardiomyocytes and do not reproduce the ECM perturbations. In this review, the different strategies to mimic the chemical, physical and topographical properties of the cardiac tissue affected by DCM are presented. The advantages and drawbacks of techniques generating anisotropy required for the cardiomyocytes alignment are discussed. In addition, the different methods creating macroporosity and favoring organotypic organization are compared. Besides, the advances in the induced pluripotent stem cells technology to generate cardiac cells from healthy or DCM patients will be described. Thanks to the biomaterial design, some features of the DCM extracellular matrix such as stiffness, porosity, topography or chemical changes can impact the cardiomyocytes function in vitro and increase their maturation. By mimicking the affected heart, both at the cellular and at the tissue level, 3D models will enable a better understanding of the pathology and favor the discovery of novel therapies.
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Affiliation(s)
- Marie Camman
- Sorbonne Université, CNRS, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, 4 place Jussieu (case 174), F-75005, Paris, France
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 7 quai St-Bernard (case 256), F-75005, Paris, France
| | - Pierre Joanne
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 7 quai St-Bernard (case 256), F-75005, Paris, France
| | - Onnik Agbulut
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), CNRS UMR 8256, Inserm ERL U1164, Biological Adaptation and Ageing, 7 quai St-Bernard (case 256), F-75005, Paris, France
| | - Christophe Hélary
- Sorbonne Université, CNRS, UMR 7574, Laboratoire de Chimie de la Matière Condensée de Paris, 4 place Jussieu (case 174), F-75005, Paris, France
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Zhong L, Su Y, Yeo SY, Tan RS, Ghista DN, Kassab G. Left ventricular regional wall curvedness and wall stress in patients with ischemic dilated cardiomyopathy. Am J Physiol Heart Circ Physiol 2009; 296:H573-84. [PMID: 19122166 DOI: 10.1152/ajpheart.00525.2008] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Geometric remodeling of the left ventricle (LV) after myocardial infarction is associated with changes in myocardial wall stress. The objective of this study was to determine the regional curvatures and wall stress based on three-dimensional (3-D) reconstructions of the LV using MRI. Ten patients with ischemic dilated cardiomyopathy (IDCM) and 10 normal subjects underwent MRI scan. The IDCM patients also underwent delayed gadolinium-enhancement imaging to delineate the extent of myocardial infarct. Regional curvedness, local radii of curvature, and wall thickness were calculated. The percent curvedness change between end diastole and end systole was also calculated. In normal heart, a short- and long-axis two-dimensional analysis showed a 41 +/- 11% and 45 +/- 12% increase of the mean of peak systolic wall stress between basal and apical sections, respectively. However, 3-D analysis showed no significant difference in peak systolic wall stress from basal and apical sections (P = 0.298, ANOVA). LV shape differed between IDCM patients and normal subjects in several ways: LV shape was more spherical (sphericity index = 0.62 +/- 0.08 vs. 0.52 +/- 0.06, P < 0.05), curvedness at end diastole (mean for 16 segments = 0.034 +/- 0.0056 vs. 0.040 +/- 0.0071 mm(-1), P < 0.001) and end systole (mean for 16 segments = 0.037 +/- 0.0068 vs. 0.067 +/- 0.020 mm(-1), P < 0.001) was affected by infarction, and peak systolic wall stress was significantly increased at each segment in IDCM patients. The 3-D quantification of regional wall stress by cardiac MRI provides more precise evaluation of cardiac mechanics. Identification of regional curvedness and wall stresses helps delineate the mechanisms of LV remodeling in IDCM and may help guide therapeutic LV restoration.
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Affiliation(s)
- Liang Zhong
- Deparment of Cardiology, National Heart Centre, Singapore
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Cabrera JR. Idiopathic dilated cardiomyopathy. Elastic parallel element dysfunction as a physiopathological hypothesis for ventricular failure. Med Hypotheses 1999; 53:260-2. [PMID: 10580534 DOI: 10.1054/mehy.1999.0768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Idiopathic dilated cardiomyopathy is a disease of unknown etiology, although the viral-immunologic pathogenesis has recently emerged as an important hypothesis. Its distinctive anatomopathologic features are: macroscopically, a great ventricular dilation with little hypertrophy, and microscopically marked diffuse interstitial fibrosis not observed in other pathologic entities with dilation. Hemodynamically, its main characteristic is a progressive loss of the systolic function, although the diastolic function is also impaired. To date it is accepted that in dilated states ventricular remodeling occurs due to sliding of fiber with a maximal sarcomere distention; it is also assumed that the ventricular dysfunction is due to a primary deficit in contractility caused by the injury and loss of myocites. HYPOTHESIS The aggressive agent mainly attacks the interstitial tissue, thus damaging the elastic parallel element structures. This results in a loss of absorbing power during diastole, starting a progressive dilation which results in maximum sarcomere distention, and compromises the ventricular function. The organ response is to create a new parallel element, which results in an increased fibrosis which also compromises this function.
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Affiliation(s)
- J R Cabrera
- Cardiology Service, A. Santamaria Academic General Hospital, Pinar del Rio, Cuba.
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4
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Reply. J Thorac Cardiovasc Surg 1998. [DOI: 10.1016/s0022-5223(98)70149-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Shimizu G, Hirota Y, Kawamura K. Empiric determination of the transition from concentric hypertrophy to congestive heart failure in essential hypertension. J Am Coll Cardiol 1995; 25:888-94. [PMID: 7884093 DOI: 10.1016/0735-1097(94)00474-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Our aim was to determine whether there is a final transition from left ventricular hypertrophy to congestive heart failure in the late stage of essential hypertension. BACKGROUND A theoretic model using the concept of systolic transmural nonuniform wall thickening was applied to develop a concentric two-shell geometry allowing evaluation of the mechanics of circumferential midwall fibers. METHODS We evaluated pressure-volume data from 46 normal control subjects (control group) and 70 patients with hypertension: 33 without hypertrophy (hypertension only group), 14 with hypertrophy (hypertrophy group) and 23 with heart failure in addition to hypertrophy (heart failure group). RESULTS End-diastolic volume index was higher in the heart failure group than in the control group (p < 0.01). Although left ventricular wall thickness and mass index were increased in both the hypertrophy and the heart failure group, concentricity indexes as assessed by ratios of left ventricular wall thickness to dimension and mass index to end-diastolic volume index were maximal in the former. Although endocardial and standard midwall fractional shortening did not differ among the control, hypertension only and heart failure groups, that of the modified midwall by concentric two-shell geometry was decreased in the hypertrophy and the heart failure groups (p < 0.05). The Hotelling T2 test and Mahalanobis distance clearly discriminated the latter two groups with end-systolic stress and modified midwall fractional shortening relation. CONCLUSIONS A fitting segmented regression model predicted a progression to hypertrophy and identified a transition from hypertrophy to heart failure by a combination of modified midwall fractional shortening and concentricity indexes.
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Affiliation(s)
- G Shimizu
- Department of Internal Medicine, Osaka Medical College, Japan
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6
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Juillière Y, Marie PY, Danchin N, Gillet C, Paille F, Karcher G, Bertrand A, Cherrier F. Serial evaluation of dilated cardiomyopathy with exercise thallium-201 tomography: correlation with the evolution of left ventricular parameters. Int J Cardiol 1994; 46:159-67. [PMID: 7814165 DOI: 10.1016/0167-5273(94)90037-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The purpose of this prospective study was to correlate (1) the initial findings of exercise thallium-201 tomography with the evolution of left ventricular parameters at long term follow-up in patients with dilated cardiomyopathy and (2) the changes of exercise thallium-201 tomography repeated 1 year later. We studied 19 men with dilated cardiomyopathy and normal coronary angiogram. Two patients died and three patients had heart transplantation during follow-up. The other 14 patients were assessed at baseline and 1-year follow-up. Thallium-201 tomograms were divided into 20 segments for each patient. Two groups were defined according to the evolution of left ventricular ejection fraction: group 1 (n = 7) had unchanged or decreased ejection fraction at follow-up (24 +/- 11% at baseline versus 22 +/- 11% at follow-up, ns) and group 2 (n = 7) had improved ejection fraction at follow-up (25 +/- 9% at baseline versus 49 +/- 8% at follow-up, P < 0.03). The number of total abnormal segments at stress were not statistically different at baseline between groups 1 and 2, and in group 1 between baseline and follow-up. Group 2 at follow-up had a reduced number of total abnormal segments (P < 0.03). The percentage of reversibility was similar in both groups at baseline and follow-up. On exercise thallium-201 tomography, neither the presence nor the reversibility of stress myocardial perfusion abnormalities can predict improvement of left ventricular ejection fraction in dilated cardiomyopathy. However, regression of dilated cardiomyopathy is accompanied by a reduction of stress myocardial perfusion abnormalities.
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Affiliation(s)
- Y Juillière
- Department of Cardiology, CHU Nancy-Brabois, Vandoeuvre-les-Nancy, France
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Fujita N, Duerinekx AJ, Higgins CB. Variation in left ventricular regional wall stress with cine magnetic resonance imaging: normal subjects versus dilated cardiomyopathy. Am Heart J 1993; 125:1337-45. [PMID: 8480586 DOI: 10.1016/0002-8703(93)91004-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We measured the variation of end-systolic wall stress and its relation to regional ejection fraction in short-axis planes through the left ventricle in normal subjects and in patients with dilated cardiomyopathy (DCM) by cine magnetic resonance imaging. There was a gradual increase in end-systolic wall stress but a gradual decrease in ejection fraction from apex to base in normal subjects (14 +/- 6 to 52 +/- 15 kdyne/cm2, 78% +/- 12% to 62% +/- 8%) and in patients with DCM (49 +/- 28 to 130 +/- 30 kdyne/cm2, 40 +/- 18 to 23% +/- 9%). The end-systolic wall stress in patients with DCM was higher than in normal subjects at every level (p < 0.01). We conclude that there is a variation in end-systolic wall stress in both normal subjects and patients with DCM with regional ejection fraction inversely related to regional end-systolic wall stress.
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Affiliation(s)
- N Fujita
- Department of Radiology, University of California, San Francisco 94143-0628
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Kurozumi H, Hayakawa M, Kajiya T, Awano K, Azumi T, Inatome T, Inoh T, Fukuzaki H. Clinical evaluation of observations in poorly contracting and nondilated left ventricles (nondilated cardiomyopathy). Am J Cardiol 1992; 69:1367-70. [PMID: 1585877 DOI: 10.1016/0002-9149(92)91240-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- H Kurozumi
- Department of Internal Medicine, Miki City Hospital, Hyogo, Japan
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Shimizu G, Hirota Y, Kita Y, Kawamura K, Saito T, Gaasch WH. Left ventricular midwall mechanics in systemic arterial hypertension. Myocardial function is depressed in pressure-overload hypertrophy. Circulation 1991; 83:1676-84. [PMID: 1827056 DOI: 10.1161/01.cir.83.5.1676] [Citation(s) in RCA: 229] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Left ventricular (LV) midwall geometry has been described conventionally as the sum of the chamber radius and half of the wall thickness; this convention is based on the assumption of uniform transmural thickening during systole. However, theoretical considerations and experimental data indicate that the inner half (inner shell) of the LV wall thickens more than the outer half (outer shell). Thus, an end-diastolic circumferential midwall fiber exhibits a relative migration toward the epicardium during systole. As a result, the conventional method provides an overestimate of the extent of the midwall fiber shortening. METHODS AND RESULTS We developed an ellipsoidal model with a concentric two-shell geometry (nonuniform thickening) to assess midwall fiber length transients throughout the cardiac cycle. This modified midwall method was used in the analysis of LV cineangiograms from 15 patients with systemic arterial hypertension and 14 normal subjects. Study groups were classified according to LV mass index (LVMI): 14 normal subjects (group I), eight hypertensive patients with a normal LVMI (group II), and seven hypertensive patients with an increased LVMI (group III). There were no significant differences in LV end-diastolic pressure or volume among the three groups; the ejection fraction was slightly greater in group II (70 +/- 5%) than in groups I (65 +/- 8%) and III (66 +/- 4%), but this trend did not achieve statistical significance. Values for endocardial and conventional midwall fractional shortening (FS) were also similar in the three groups. By contrast, FS by the concentric two-shell geometry (modified midwall method) in group III (16 +/- 2%) was significantly less than that seen in groups I and II (21 +/- 4% and 21 +/- 5%, respectively; both p less than 0.05). This difference achieves greater importance when it is recognized that mean systolic circumferential stress was lower in group III (151 +/- 22 g/cm2) than in groups I and II (244 +/- 37 g/cm2 and 213 +/- 38 g/cm2, respectively; both p less than 0.01). The midwall stress-shortening coordinates in six of the seven group III patients were outside the 95% confidence limits for the normal (group I) subjects. Thus, despite a normal ejection fraction, systolic function is subnormal in hypertensive patients with LV hypertrophy. CONCLUSIONS Chamber dynamics provide an overestimate of myocardial function, especially when LV wall thickness is increased. This is due to a relatively greater contribution of inner shell thickening in pressure-overload hypertrophy.
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Affiliation(s)
- G Shimizu
- Department of Internal Medicine, Osaka Medical College, Japan
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Hayashida W, Kumada T, Nohara R, Tanio H, Kambayashi M, Ishikawa N, Nakamura Y, Himura Y, Kawai C. Left ventricular regional wall stress in dilated cardiomyopathy. Circulation 1990; 82:2075-83. [PMID: 2242531 DOI: 10.1161/01.cir.82.6.2075] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Left ventriculography with simultaneous pressure micromanometry was performed in 11 normal control subjects and 17 patients with dilated cardiomyopathy (DCM). Left ventricular silhouettes in the right anterior oblique projection were divided into eight areas, and regional wall stress was computed by Janz's method in each area excluding the two most basal areas. Wall stress was higher in DCM patients than in control subjects (p less than 0.01). The percent area changes from end diastole to end systole in each area were lower in DCM patients than in control subjects (mean for six areas, 22 +/- 14% versus 54 +/- 9%, respectively, p less than 0.01), but the coefficient of variation for the percent area changes in the six areas of the left ventricle in DCM patients was greater than that in control subjects (32 +/- 17% versus 15 +/- 4%, respectively, p less than 0.01), indicating regional differences in hypokinesis. There was a significant negative correlation between end-systolic regional wall stress and percent area change (r = -0.60 to -0.86, p less than 0.05) in each area. Thus, excessive regional afterload may play an important role in causing regional hypokinesis in DCM.
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Affiliation(s)
- W Hayashida
- Department of Internal Medicine, Faculty of Medicine, Kyoto University, Japan
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11
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Hasenfuss G, Holubarsch C, Heiss HW, Just H. Influence of UDCG-115 on hemodynamics and myocardial energetics in patients with idiopathic dilated cardiomyopathy. Am Heart J 1989; 118:512-9. [PMID: 2773772 DOI: 10.1016/0002-8703(89)90266-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The influence of the new inotropic and vasodilating agent UDCG-115 on hemodynamics and myocardial oxygen metabolism was investigated in 11 patients with idiopathic dilated cardiomyopathy (New York Heart Association class II to III). After intravenous administration of UDCG-115, cardiac index increased from 3.03 +/- 0.68 to 3.76 +/- 1.07 L/min/m2 (p less than 0.01), left ventricular ejection fraction increased from 31 +/- 13 to 39 +/- 16% (p less than 0.01), and maximum rate of left ventricular pressure rise increased from 935 +/- 248 to 1056 +/- 284 mm Hg/sec (p less than 0.05). Left ventricular end-diastolic wall stress (index of preload) and left ventricular end-systolic wall stress (index of afterload) decreased by 41% (p less than 0.01) and 34% (p less than 0.001), respectively. Heart rate did not change significantly. With UDCG-115 myocardial oxygen consumption decreased from 14.3 +/- 5.1 to 10.6 +/- 3.8 ml/min/100 gm (p less than 0.05), and the ratio of myocardial oxygen supply to myocardial oxygen demand increased from 1.40 +/- 0.08 to 1.53 +/- 0.17 (p less than 0.05). Thus intravenous UDCG-115 improves left ventricular function by increasing inotropism and reducing preload and afterload in patients with idiopathic dilated cardiomyopathy and moderate congestive heart failure. The systemic hemodynamic actions are associated with favorable effects on myocardial energetics.
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Affiliation(s)
- G Hasenfuss
- Department of Internal Medicine, University of Freiburg Medical School, West Germany
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Dall'Aglio V, Nicolosi GL, Burelli C, Zardo F, Pavan D, Lestuzzi C, Zanuttini D. Echocardiographic findings of left ventricular hypertrophy and normalization of parameters of left ventricular function in patients with previous evidence of dilated and poorly contracting left ventricle and coexisting systemic hypertension. Clin Cardiol 1989; 12:91-6. [PMID: 2523768 DOI: 10.1002/clc.4960120205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We report 6 cases of dilated left ventricle with poor left ventricular function and coexisting systemic hypertension in whom left ventricular hypertrophy and normalization of left ventricular function and dimensions have been subsequently documented by M-mode and two-dimensional echocardiographic follow-up studies. Four patients were in New York Heart Association functional Class IV, one in Class III, and one in Class II when first seen. Normalization of left ventricular function and dimensions and features of left ventricular hypertrophy (fractional shortening from 15.0 +/- 5.2 to 39.7 +/- 5.4, left ventricular end-diastolic diameter from 6.6 +/- 0.6 to 4.6 +/- 0.6 cm, left ventricular end-systolic diameter from 5.6 +/- 0.8 to 2.8 +/- 0.6 cm, left ventricular end-diastolic radius/posterior wall thickness from 3.1 +/- 0.5 to 2.0 +/- 0.4, interventricular septum thickness from 1.2 +/- 0.3 to 1.5 +/- 0.3 cm, left atrium from 4.6 +/- 0.6 to 3.5 +/- 0.9 cm) were achieved after adequate medical treatment at the end of the follow-up (11-39 months). It appears from this study that normalization of left ventricular dimensions and function with features of left ventricular hypertrophy can occur after adequate treatment in patients with echocardiographic findings of dilated and poorly contracting left ventricle and coexisting systemic hypertension. It is conceivable, in such cases, to classify the dilatation of the left ventricle as secondary and to suggest the hypothesis of a cause-effect relationship between therapy and normalization of left ventricular parameters with findings of left ventricular hypertrophy. Further studies are needed to clarify this phenomenon.
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Affiliation(s)
- V Dall'Aglio
- Divisione di Cardiologia, Ospedale Civile, Pordenone, Italy
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Abstract
A histopathological index of contractility failure, which was reported to be accurate for the diagnosis of idiopathic dilated or congestive cardiomyopathy in Japan, was used to assess endomyocardial biopsy specimens from 41 Dutch patients with suspected dilated cardiomyopathy. The calculated index had a sensitivity of 62.5% and a specificity of 68% for idiopathic dilated or congestive cardiomyopathy. These disappointing results indicate that the histopathological index of contractility failure does not reliably distinguish between idiopathic dilated cardiomyopathy and other diseases that cause congestive heart failure.
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Nakayama Y, Shimizu G, Hirota Y, Saito T, Kino M, Kitaura Y, Kawamura K. Functional and histopathologic correlation in patients with dilated cardiomyopathy: an integrated evaluation by multivariate analysis. J Am Coll Cardiol 1987; 10:186-92. [PMID: 3597987 DOI: 10.1016/s0735-1097(87)80178-x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
To correlate left ventricular function and histologic features in patients with dilated cardiomyopathy, precise indexes of hemodynamics and semiquantitative histologic data were combined for multivariate analysis. Right endomyocardial biopsy was performed at the time of cardiac catheterization. Five hemodynamic indexes were used for functional assessment: ejection fraction, ratio of end-systolic stress to volume index, end-diastolic stress, time constant (T) of left ventricular pressure fall, and end-systolic stress. Six histologic findings (disarray of myofibers, hypertrophy of myofibers, scarcity of myofibrils, nuclear changes of myofibers, vacuolization of myofibers and proliferation of collagen fibers) were graded from (-) to (4+). Each finding was assigned to category (-) or (+) according to the absence or presence of significant abnormality. Ordinary statistical analysis revealed that, although ejection fraction was lower in category (+) for proliferation of collagen fibers, ratio of end-systolic to volume index was reduced for category (+) of hypertrophy of myofibers. A significant correlation was present between hypertrophy of myofibers and proliferation of collagen fibers by Spearman rank correlation. When principal component analysis was applied to the hemodynamic data, two principal components could be extracted. Fisher's discriminant analysis could clearly differentiate two categories (-) and (+) in the semiquantitative histologic finding of proliferation of collagen fibers. The analysis indicated that contractility was reduced with elevated afterload in that category (+). Thus, proliferation of collagen fibers may play a pivotal role in deteriorating contractility in patients with dilated cardiomyopathy.
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Abstract
The effectiveness of postextrasystolic potentiation (PESP) was assessed to detect residual function of the left ventricle in seven patients with idiopathic dilated cardiomyopathy (IDC). The postextrasystolic changes in the aortic pressure pulse, global left ventricular function, and quantitative regional left ventricular wall motion were investigated. PESP caused an increase in the peak systolic aortic pressure (116 +/- 17 to 130 +/- 25 mm Hg, p less than 0.01), a decrease in the peak diastolic aortic pressure (74 +/- 12 to 61 +/- 11 mm Hg, p less than 0.001), a decrease in preejection period/left ventricular ejection time (PEP/LVET) ratio (0.637 +/- 0.136 to 0.457 +/- 0.097, p less than 0.001), and an increase in the global left ventricular ejection fraction (LVEF) (0.26 +/- 0.09 to 0.40 +/- 0.12, p less than 0.01). Postextrasystolic changes in LVEF were inversely related to changes in PEP/LVET (r = -0.76, p less than 0.05). The postextrasystolic patterns of the regional wall motion of the left ventricle were different in each patient. The results of this study suggest that residual left ventricular function can be detected in patients with IDC by their response to PESP.
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