Abstract
In penetrating the heart and developing in it, Trypanosoma cruzi produces an immunoallergic reaction that leads to changes in the histological structure of the myocardium; these changes alter the fundamental properties of the heart, causing fundamental dynamic disorders and morphological changes in the organ.
In Chagas' cardiomyopathy, the velocity of impulse propagation diminishes in the auricular and ventricular musculature, altering the activation mechanism, this being shown by changes in the P-wave and in ventricular focal blocks.
The functional refractory period (FRP) is shortened in the auricular and ventricular tissue and constitutes, together with changes in conductivity, the physiopathological basis that explains the circus movement—the fundamental factor of the arrhythmias of this stage of the disease. Localization of the inflammation in the A-V conduction system increases the duration of the FRP, producing all types of A-V block.
The oedema and the cellular interstitial infiltration seen during this acute phase reduce the distensibility of the fibres; this, in turn, limits their contractility, producing a decrease in systolic volume and an increase in the final diastolic pressure in the chambers of the heart—fundamental factors in reducing kinesia and in increasing the heart's volume.
In the chronic phase, destruction of the contractile tissue and fibroblastic proliferation bring into play compensatory mechanisms that maintain the strength of cardiac contractions; the elongation of the fibres and the nature of the dynamic pressure—volume curves explain the dilatation of the chambers of the heart and the dynamic changes seen in this phase of the disease.
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Selected References
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- Anselmi A., Gurdiel O., Suarez J. A., Anselmi G. Disturbances in the A-V conduction system in Chagas' myocarditis in the dog. Circ Res. 1967 Jan;20(1):56–64. doi: 10.1161/01.res.20.1.56. [DOI] [PubMed] [Google Scholar]
- Anselmi A., Pifano F., Suarez A., Dominguez A., Diaz Vázquez A., Anselmi G. Experimental Schizotrypanum cruzi myocarditis. Correlation between histopathologic and electrocardiographic findings in experimental Chagas' heart disease. Am Heart J. 1965 Nov;70(5):638–656. doi: 10.1016/0002-8703(65)90393-5. [DOI] [PubMed] [Google Scholar]
- Anselmi A., Pifano F., Suarez J. A., Gurdiel O. Myocardiopathy in Chagas' disease. I. Comparative study of pathologic findings in chronic human and experimental Chagas' myocarditis. Am Heart J. 1966 Oct;72(4):469–481. doi: 10.1016/0002-8703(66)90104-9. [DOI] [PubMed] [Google Scholar]
- Anselmi A., Pisani F., Suárez J. A., Gurdiel O., Lapco L. Cardiovascular radiology in acute and chronic Chagas' myocardiopathy. Morphologic and dynamic study of the cardiac contour correlated with the histologic changes observed in myocardiopathies attributed to Schizotrypanum cruzi. Am Heart J. 1967 May;73(5):626–639. doi: 10.1016/0002-8703(67)90172-x. [DOI] [PubMed] [Google Scholar]
- CROSS C. E., RIEBEN P. A., SALISBURY P. F. Influence of coronary perfusion and myocardial edema on pressure-volume diagram of left ventricle. Am J Physiol. 1961 Jul;201:102–108. doi: 10.1152/ajplegacy.1961.201.1.102. [DOI] [PubMed] [Google Scholar]
- DIAS E., LARANJA F. S., MIRANDA A., NOBREGA G. Chagas' disease; a clinical, epidemiologic, and pathologic study. Circulation. 1956 Dec;14(6):1035–1060. doi: 10.1161/01.cir.14.6.1035. [DOI] [PubMed] [Google Scholar]
- Doi Y. Studies on muscular contraction: II. The relation between the maximal work and the tension developed in a muscle twitch, and the effects of temperature and extension. J Physiol. 1921 Mar 15;54(5-6):335–341. doi: 10.1113/jphysiol.1921.sp001934. [DOI] [PMC free article] [PubMed] [Google Scholar]
- JOSELEVICH M., MARKUS Z., GERMAN ZWAIG P., VIDAL R. P. Sintomatología y diagnóstico de la cardiopatía chagásica crónica. Prensa Med Argent. 1958 Jan 10;45(2):191–201. [PubMed] [Google Scholar]
- LARANJA F. S., DIAS E., DUARTE E., PELLEGRINO J. Observaçes clänicas e epidemiológicas sôbre a moléstia de Chagas no oesto de Minas Gerais. Hospital (Rio J) 1951 Dec;40(6):945–988. [PubMed] [Google Scholar]
- LINN H., KLINE I. K., ROSENBLUM P., SILBER E. N., SHAFFER A. B. LEFT VENTRICULAR CONSTRICTION DUE TO MYOCARDITIS IN A CHILD. Am J Cardiol. 1964 Feb;13:270–277. doi: 10.1016/0002-9149(64)90182-1. [DOI] [PubMed] [Google Scholar]
- REY D. C. Cardiopatía chagásica crónica en la pcia de Buenos Aires. Dia Med. 1957 Sep 16;29(65):2332–2334. [PubMed] [Google Scholar]
- ROSENBLUETH A., ALANIS J., LOPEZ E., RUBIO R. The adaptation of ventricular muscle to different circulatory conditions. Arch Int Physiol Biochim. 1959 Jun;67(3):358–373. doi: 10.3109/13813455909072295. [DOI] [PubMed] [Google Scholar]
- ROSENBLUETH A., ALANIS J., RUBIO R. Some properties of the mammalian ventricular muscle. Arch Int Physiol Biochim. 1959 Apr;67(2):276–293. doi: 10.3109/13813455909074433. [DOI] [PubMed] [Google Scholar]
- SALISBURY P. F., CROSS C. E., RIEBEN P. A. Distensibility and water content of heart muscle before and after injury. Circ Res. 1960 Jul;8:788–793. doi: 10.1161/01.res.8.4.788. [DOI] [PubMed] [Google Scholar]
- SCHABELMAN M., ROSENBAUM M. B. Miocarditis crónica chágasica en San Juan. Prensa Med Argent. 1958 Jan 24;45(4):395–400. [PubMed] [Google Scholar]