Chagas' Disease

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Echocardiography 1998 Apr;15(3):271-278

Echocardiographic and Clinical Predictors of Mortality in Chronic Chagas' Disease.

Rodriguez-Salas LA, Klein E, Acquatella H, Catalioti F, Davalos V V, Gomez-Mancebo JR, Gonzalez H, Bosch F, Puigbo JJ.

Centro Medico, San Bernardino, Caracas 1011, Venezuela.

BACKGROUND: In a prospective epidemiological study of chronic Chagas' disease, several clinical and echocardiographic variables were analyzed as predictors of mortality. METHODS: Among 960 subjects seropositive for Chagas' disease who were examined betwee n June 1981 and June 1992, 283 had echocardiograms. RESULTS: During a mean follow-up period of 48.3 +/- 36.4 months (range, 1-156 months), 108 subjects died. Echocardiographic end-diastolic and -systolic left ventricular internal dimensions, fractional sh ortening, radius-to-thickness ratio, left ventricular mass, mitral E-point septal separation, and 17 other nonechocardiographic variables were predictors of death on univariate analysis (P < 0.001 for each). On stepwise multiple regression analysis of 215 subjects, significant risk covariates in a Cox model analysis were clinical group (P < 0.0001), M-mode echocardiographic E-point septal separation of 22 mm (P = 0.003), presence of first- or second-degree heart block (P = 0.003), chest radiologic cardiot horacic ratio >/= 0.55 (P = 0.012), presence of electrocardiographic ST segment elevation on precordial leads (P = 0.014), age >/= 56 years (P = 0.028), and presence of right bundle-branch block (P = 0.045). Patients with an apical aneurysm on two-dimensi onal echocardiography had an increased mortality (Chi-square = 11.5, P < 0.001). CONCLUSIONS: Echocardiography is a valuable tool to assess the risk of death in prospective studies on chronic Chagas' heart disease.

Am Heart J 2001 Feb;141(2):260-5

Parasympathetic dysautonomia precedes left ventricular systolic dysfunction in Chagas disease.

Ribeiro AL, Moraes RS, Ribeiro JP, Ferlin EL, Torres RM, Oliveira E, Rocha MO.

Hospital das Clinicas and School of Medicine, Federal University of Minas Gerais, Rua Companha, 98/101, 30310-770, Belo Horizonte, MG, Brazil.

BACKGROUND: Parasympathetic dysautonomia is an established feature of advanced Chagas cardiomyopathy. However, in the absence of cardiac involvement, the presence of vagal dysfunction remains controversial. In a cross-sectional study, we compared patients with Chagas disease without cardiac involvement and healthy individuals by three different methods to determine whether vagal dysfunction is present in the early phase of Chagas disease. METHODS: Sixty-one patients with Chagas disease without cardiac inv olvement and 38 controls were submitted to respiratory sinus arrhythmia test and 24-hour Holter monitoring. Vagal heart influences were assessed by the expiratory/inspiratory (E/I) ratio, time-domain indexes of heart rate variability (HRV), and by the qua ntification of a 3-dimensional return map. RESULTS: The two groups were comparable in terms of left ventricular ejection fraction and left ventricular end-diastolic dimension. Compared with the control group, patients with Chagas disease had significantly lower values of the E/I ratio (mean +/- SD: 1.38 +/- 0.02 and 1.25 +/- 0.02, P <.004) and short-term indexes of HRV (median [interquartile range]-rMSSD: 23 [18-27] and 17 [13-23], P =.00; pNN50: 11 [7-17] and 6 [2-12], P =.00). P(3), a beat-to-beat HRV i ndex derived from the 3-dimensional return map, also was significantly reduced in the Chagas disease group (mean +/- SD: 118 +/- 5 vs 100 +/- 4, P =.00). None of these indexes of vagal heart control were significantly correlated with left ventricular func tion or to the presence of esophageal radiologic abnormalities. CONCLUSION: Parasympathetic dysautonomia is an independent and early phenomenon in Chagas disease and may precede left ventricular systolic dysfunction.

J Am Coll Cardiol 1999 Feb;33(2):522-9

Limited myocardial contractile reserve and chronotropic incompetence in patients with chronic Chagas' disease: assessment by dobutamine stress echocardiography.

Acquatella H, Perez JE, Condado JA, Sanchez I.

Centro de Investigaciones J.F. Torrealba, Hospital Universitario de Caracas, Venezuela.

OBJECTIVES: To determine whether dobutamine stimulation in patients with Chagas' disease may uncover abnormal contractile responses as seen in ischemic myocardium. BACKGROUND: Segmental left ventricular (LV) dysfunction in the absence of coronary atherosc lerosis is frequently seen in patients with chronic Chagas' heart disease. Myocardial ischemia and coronary microcirculation abnormalities have been found in animal models and in humans with Chagas' disease. In addition, chagasic sera may contain autoanti bodies against human beta-adrenergic receptors. METHODS: Two groups of patients with Chagas' disease were studied by echocardiography: group 1 (n = 12) without and group 2 (n = 14) with LV segmental wall motion abnormalities (mostly apical aneurysm). Ten normal subjects served as control subjects. We performed qualitative assessment of wall motion and quantitative evaluation of LV cavity under baseline conditions and after dobutamine stimulation. RESULTS: Patients with Chagas' disease exhibited a blunted inotropic and chronotropic response to dobutamine stimulation. After dobutamine, fractional area change in Chagas' group 1 (54.7+/-6.6%; SD) and in group 2 (35.1+/-12.1%) were significantly lower than control group (66.7+/-2.5%; p < 0.001). In addition, i n 6 of 14 group 2 patients, dobutamine induced a biphasic response with improvement at low dose and deterioration at peak dose, as seen in patients with coronary artery disease. Although the three groups had similar basal mean heart rates and attained a s imilar mean peak dobutamine doses, both groups of patients with Chagas' disease had a significantly blunted mean heart rate effect after dobutamine (p < 0.0001). CONCLUSIONS: Thus, dobutamine stimulation unmasks a chronotropic incompetence and a blunted m yocardial contractile response in chagasic patients, even in those with no overt manifestation of heart disease.

Am J Cardiol 1998 Jul 15;82(2):197-202

Comment in: Am J Cardiol. 1998 Dec 15;82(12):1561

Echocardiographic analysis of regional and global left ventricular shape in Chagas' cardiomyopathy.

Patel AR, Lima C, Parro A, Arsenault M, Vannan MA, Pandian NG.

Cardiovascular Imaging and Hemodynamic Laboratory, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts, USA.

Chagas' heart disease is a common form of cardiomyopathy in Latin America and an important cause of cardiac morbidity and mortality there. Left ventricular (LV) apical aneurysm and LV dysfunction are frequent findings in Chagas' cardiomyopathy. Because ca rdiac shape has important implications for LV function, we sought to characterize regional and global changes in LV geometry in Chagas' heart disease. Quantitative shape analysis was performed on 2-dimensional echocardiograms from 43 patients with Chagas' cardiomyopathy. Regional shape was quantitated by measuring endocardial curvature and global shape was evaluated by Fourier shape analysis of the endocardial contour. Data from 22 age- and sex-matched normal test subjects were used for comparison. Region al shape analysis demonstrated decreased apical curvature (consistent with blunting of normal apical shape) in the group with Chagas' disease compared with controls (apical 2-chamber view: 19 +/- 1 vs 24 +/- 1 [p = 0.0039] at end-diastole and 20 +/- 2 vs 29 +/- 3 [p = 0.0019] at end-systole). Fourier shape power index was decreased in the Chagas' group, consistent with a more spherical ventricle (apical 2-chamber view: 9 +/- 1 vs 17 +/- 2 [p <0.0001] at end-diastole and 12 +/- 1 vs 35 +/- 3 [p <0.0001] at end-systole). Shape changes among the population with Chagas' disease were further evaluated in those with end-diastolic volumes equal to or greater than the median for the group (104 ml) and those < 104 ml. Global shape did not differ between patients w ith dilated ventricles and those with relatively nondilated ventricles. Diastolic Fourier shape power index = 8 +/- 2 in dilated ventricles compared with 9 +/- 5 in nondilated ventricles (p = 0.53); systolic Fourier shape power index = 10 +/- 2 in dilated versus 14 +/- 2 in nondilated ventricles (p = 0.15) (apical 2-chamber view). In Chagas' cardiomyopathy, LV apical deformation results in disruption of the optimal global prolate-ellipsoid shape, even in patients with relatively preserved LV volumes.

Arch Inst Cardiol Mex 1995 May-Jun;65(3):265-9

Mitral subvalvular aneurysm of probable chagasic etiology

Garcia Hernandez N, Espinosa Caleti B, Palacios Macedo X.

Hospital de Cardiologia, Centro Medico Nacional, Mexico, D.F.

The case report is a woman 45 years old from a rural zone of the Federal District (Mexico City) with subvalvular mitral aneurysm of probable chagasic origin. Its main clinic manifestation was caused by the presence of recurrent ventricular arrhythmias ref ractory to medical treatment. The diagnosis was made by means of the serology, echocardiography, cineangiography and endocardial biopsy. The treatment consisted in the surgical resection of the aneurysm with successful evolution.

Rev Paul Med 1995 Mar-Apr;113(2):785-90

The apical ventricular lesion in Chagas' heart disease.

Nogueira EA, Ueti OM, Vieira WR.

Department of Internal Medicine, Universidade Estadual de Campinas-Sao Paulo, Brazil.

Apical lesions of the left ventricle, ranging from endocardial thickening to aneurysms, are commonly found in Chagas' heart disease. These abnormalities can be identified by ventriculography, two-dimensional echocardiography and radioisotopic studies. Gen erally, clinical manifestations are limited to arrhythmias and thromboembolic. The lesions are usually small and apparently do not play a role in ventricular dysfunction.

Am J Vet Res 1992 Apr;53(4):521-7

Electrocardiographic and echocardiographic features of trypanosomiasis in dogs inoculated with North American Trypanosoma cruzi isolates.

Barr SC, Holmes RA, Klei TR.

Department of Veterinary Microbiology and Parasitology, Louisiana State University, Baton Rouge 70803.

Purebred Beagles were inoculated with Trypanosoma cruzi isolates from a North American opossum or armadillo (Tc-W), and dog (Tc-D). Although Tc-D established infection in dogs, the dogs did not develop cardiac abnormalities. Dogs inoculated with Tc-W deve loped acute myocarditis associated with increases in P-R interval, atrioventricular block, depression of R wave amplitude and shifts in mean electrical axis. Echocardiograms were normal during this stage. Three Tc-W-inoculated dogs died during the acute s tage. Following the acute stage, 5 of 8 Tc-W-inoculated dogs entered an indeterminate stage in which ECG changes were minor and echocardiograms were normal. Progression to the chronic stage in 5 of the 8 Tc-W-inoculated dogs was indicated by development o f ventricular-based arrhythmias, mainly ventricular premature contractions, between postinoculation days 60 and 170. In some dogs, ventricular premature contractions were multifocal. Electrocardiographic abnormalities progressively degenerated to various forms of ventricular tachycardia. Worsening ECG coincided with loss of left ventricular function as measured by echocardiography. Mean percent ejection fraction and percentage of fractional shortening decreased to 63% and 52% of control values, respective ly. The left ventricular free wall (LVFW) thickness decreased and % septal: % LVFW thickening ratio increased, indicating a relative preservation of septal wall motion and LVFW hypokinesis.

J Am Soc Echocardiogr 1988 Jan-Feb;1(1):60-8

Echocardiographic recognition of Chagas' disease and endomyocardial fibrosis.

Acquatella H, Schiller NB.

Department of Medicine, University of California, San Francisco 94143-0214.

Chagas' heart disease and endomyocardial fibrosis are common medical conditions in Central and South America but are only rarely encountered in North America. In the small number of patients who have these conditions, recognition is frustrating because of a lack of familiarity with their characteristic echocardiographic pattern. In Chagas' heart disease a left ventricular apical aneurysm is characteristic, but in contrast to coronary artery disease, septal involvement is minimal. In endomyocardial fibrosi s apical obliteration with a small inwardly moving left ventricular cavity, large atria, and atrioventricular valvular insufficiency are typical features. It is the aim of this article to present the characteristic echocardiographic findings with these co nditions and thereby facilitate the recognition when they appear in nonendemic areas.

Int J Cardiol 1985 Dec;9(4):417-24

Abnormal left ventricular diastolic function in chronic Chagas' disease: an echocardiographic study.

Caeiro T, Amuchastegui LM, Moreyra E, Gibson DG.

Simultaneous M-mode echocardiograms and phonocardiograms were recorded in 19 patients with chronic Chagas' disease, and were digitised and compared with normal in order to study systolic and diastolic left ventricular function. Five of the patients were i n New York Heart Association class 1, 9 in class 2, and 5 in class 3. Left ventricular cavity dimensions were increased in 3 and shortening fraction reduced in 1. Peak velocity of circumferential fibre shortening was below the 95% confidence limit of norm al in 9. In contrast to previous echocardiographic studies, diastolic abnormalities were common, with prolongation of isovolumic relaxation time in 9 patients and reduced rate of dimension increase in 11. However, in spite of regional disease, documented angiographically in 5 of 6 patients, there was no evidence of asynchronous wall motion during relaxation seen in patients with coronary artery disease and comparable segmental abnormalities of wall motion. The relative timing of aortic valve closure and m inimum cavity dimension was normal in all but 3 patients, and a significant dimension change during isovolumic relaxation in only one. Thus diastolic disturbances are common at all stages of Chagas' disease, and may represent a fundamental aspect of the p athological process as it affects the left ventricle.

Br Heart J 1985 Mar;53(3):298-309

Echocardiographic features of impaired left ventricular diastolic function in Chagas's heart disease.

Combellas I, Puigbo JJ, Acquatella H, Tortoledo F, Gomez JR.

To study left ventricular diastolic function in Chagas's disease, simultaneous echocardiograms, phonocardiograms, and apexcardiograms were recorded in 20 asymptomatic patients with positive Chagas's serology and no signs of heart disease (group 1), 12 wit h Chagas's heart disease and symptoms of ventricular arrhythmia but no heart failure (group 2), 20 normal subjects (group 3), and 12 patients with left ventricular hypertrophy (group 4). The recordings were digitised to determine left ventricular isovolum ic relaxation time and the rate and duration of left ventricular cavity dimension increase and wall thinning. In groups 1 and 2 (a) aortic valve closure (A2) and mitral valve opening were significantly delayed relative to minimum dimension and were associ ated with prolonged isovolumic relaxation, (b) left ventricular cavity size was abnormally increased during isovolumic relaxation and abnormally reduced during isovolumic contraction, and (c) peak rate of posterior wall thinning and dimension increase wer e significantly reduced and duration of posterior wall thinning was significantly prolonged; both of these abnormalities occurred at the onset of diastolic filling. These abnormalities were more pronounced in group 2 and were accompanied by an increase in the height of the apexcardiogram "a" wave, an indication of pronounced atrial systole secondary to end diastolic filling impairment due to reduced left ventricular distensibility. Group 4, which had an established pattern of diastolic abnormalities, show ed changes similar to those in group 2; however, the delay in aortic valve closure (A2) and in mitral valve opening and the degree of dimension change were greater in the latter group. Thus early isovolumic relaxation and left ventricular abnormalities we re pronounced in the patients with Chagas's heart disease and may precede systolic compromise, which may become apparent in later stages of the disease. The digitised method is valuable in the early detection of myocardial damage.

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