ABSTRACT
BACKGROUND: Polymerase chain reaction (PCR) allows detection of Trypanosoma cruzi in blood throughout the course of Chagas' disease. OBJECTIVE: To determine whether T cruzi DNA detected by PCR is associated with progression to chronic Chagas cardiomyopathy. DESIGN: Prospective cohort study. SETTING: A tertiary care centre in Argentina. PATIENTS: 56 consecutive patients with chronic T cruzi infection. METHODS: Clinical examination, ECG, and Doppler echocardiography were carried out at baseline and at the end of the follow up. Detection of T cruzi DNA by PCR amplifying a nuclear sequence was undertaken in all patients at baseline. MAIN OUTCOME MEASURES: Progression was defined as death from chronic cardiomyopathy or the presence of a new ECG or left ventricular echocardiographic abnormality at the end of follow up. RESULTS: The 56 patients (21 male, 35 female; mean (SD) age, 56.0 (11.3) years) were followed for a mean 936.3 (244.39) days. Progression to cardiomyopathy was detected in 12 patients (21.4%). Three of these patients died after baseline evaluation. Univariate analysis showed that a positive PCR (relative risk 4.09, 95% confidence interval (CI) 1.60 to 9.85) and male sex (5.00, 95% CI 1.65 to 15.73) were associated with progression. Multivariable logistic regression indicated that both sex and PCR were independent variables affecting the outcome. CONCLUSIONS: In a cohort of seropositive individuals, patients with T cruzi DNA detected by PCR and male patients were at higher risk of progression. These results highlight the importance of T cruzi in the pathophysiology of chronic cardiomyopathy.
Subject(s)
Chagas Cardiomyopathy/parasitology , Parasitemia/parasitology , Trypanosoma cruzi/isolation & purification , Adult , Aged , Aged, 80 and over , Animals , Chagas Cardiomyopathy/diagnosis , Chagas Cardiomyopathy/physiopathology , Cohort Studies , DNA, Protozoan/analysis , Disease Progression , Electrocardiography , Female , Follow-Up Studies , Heart Block/parasitology , Humans , Male , Middle Aged , Parasitemia/diagnosis , Parasitemia/physiopathology , Polymerase Chain Reaction/methods , Prognosis , Prospective Studies , Risk Factors , Sex Factors , Stroke VolumeSubject(s)
Chagas Cardiomyopathy/blood , Endothelin-1/blood , Adult , Chagas Disease/blood , Chronic Disease , Female , Humans , Male , Middle Aged , RadioimmunoassaySubject(s)
Coronary Disease/diagnostic imaging , Heart/diagnostic imaging , Radioisotopes , Thallium , Adult , Aged , Exercise Test , Female , Humans , Male , Middle Aged , Radionuclide Imaging , Regression AnalysisABSTRACT
Se estudiaron 20 pacientes con TI 201 posterior al ejercicio supino, con imágenes secuenciales de miocardio en múltiples posiciones. La centellografía se interpretó visualmente y cuantificando la actividad regional del Tl 201, calculándose por regresión lineal, el coeficiente fraccional (K) de lavado segmentario. Se analizaron 60 segmentos divididos según la severidad arteriográfica de estenosis coronaria en: a) 24 segmentos con estenosis no significativa: usados para establecer el criterio cuantitativo de normalidad; el límite superior desviado 2DS de la media fue -0,0042. La especificidad de ambas interpretaciones fue del 96 y 100%; b) 7 segmentos con estenosis moderada; c) 19 segmentos con estenosis severa, y d) 10 segmentos con estenosis de infarto. La sensibilidad de la interpretación visual y del método cuantitativo para detectar las diferentes estenosis fue: nula y del 42,8% para las moderadas; del 57,8 y 56,6% para las severas y del 100 y 20% para las de infarto. El método cuantitativo aumentó al visual la detección de las estenosis individuales severas de la ADAI del 62,5 al 87,5%, de la ACI del 50 al 75%, de la ACD del 66,6% al 100% y para detectar la enfermedad de múltiples vasos en presencia de IAM previo del 66,6 al 77,7%. Concluimos que el coeficiente fraccional (K) de lavado segmentario del Tl 201 debe ser incorporado a la interpretación visual de la centellografía de miocardio para el diagnóstico de enfermedad coronaria
Subject(s)
Adult , Middle Aged , Humans , Male , Female , Coronary Disease , Heart , Radioisotopes/therapeutic use , Thallium , Exercise Test , Perfusion , Regression AnalysisABSTRACT
Se estudiaron 20 pacientes con TI 201 posterior al ejercicio supino, con imágenes secuenciales de miocardio en múltiples posiciones. La centellografía se interpretó visualmente y cuantificando la actividad regional del Tl 201, calculándose por regresión lineal, el coeficiente fraccional (K) de lavado segmentario. Se analizaron 60 segmentos divididos según la severidad arteriográfica de estenosis coronaria en: a) 24 segmentos con estenosis no significativa: usados para establecer el criterio cuantitativo de normalidad; el límite superior desviado 2DS de la media fue -0,0042. La especificidad de ambas interpretaciones fue del 96 y 100%; b) 7 segmentos con estenosis moderada; c) 19 segmentos con estenosis severa, y d) 10 segmentos con estenosis de infarto. La sensibilidad de la interpretación visual y del método cuantitativo para detectar las diferentes estenosis fue: nula y del 42,8% para las moderadas; del 57,8 y 56,6% para las severas y del 100 y 20% para las de infarto. El método cuantitativo aumentó al visual la detección de las estenosis individuales severas de la ADAI del 62,5 al 87,5%, de la ACI del 50 al 75%, de la ACD del 66,6% al 100% y para detectar la enfermedad de múltiples vasos en presencia de IAM previo del 66,6 al 77,7%. Concluimos que el coeficiente fraccional (K) de lavado segmentario del Tl 201 debe ser incorporado a la interpretación visual de la centellografía de miocardio para el diagnóstico de enfermedad coronaria (AU)
Subject(s)
Adult , Middle Aged , Aged , Humans , Male , Female , Coronary Disease/diagnostic imaging , Heart/diagnostic imaging , Radioisotopes/therapeutic use , Thallium/diagnosis , Exercise Test , Perfusion , Regression AnalysisSubject(s)
Chagas Cardiomyopathy/physiopathology , Chagas Disease/physiopathology , Animals , Autonomic Nervous System/physiopathology , Blood Pressure , Chagas Disease/mortality , Coronary Circulation , Heart Rate , Heart Ventricles/physiopathology , Humans , Myocardial Contraction , Physical Exertion , Renin/bloodABSTRACT
The prevalence of slow heart rate was investigated among 222 patients with Chagas' disease, 50 normal subjects, and 55 patients with non-chagasic heart failure. In any decade of life the basal heart rate of patients with chagasic heart failure was always significantly lower (P less than 0.001) than the basal heart rate of non-chagasic heart failure patients, and also lower than the basal heart rate of normal subjects. There were no significant differences between chagasic patients without heart failure and normal subjects. It is concluded that patients with heart failure of chagasic etiology show slow heart rates.
Subject(s)
Bradycardia/etiology , Chagas Disease/physiopathology , Adult , Age Factors , Aged , Chagas Disease/complications , Chronic Disease , Heart Failure/etiology , Heart Rate , Humans , Middle AgedABSTRACT
The purpose of this study was to investigate the sympathetic nervous system function in 34 patients with chronic Chagas' disease. The tilting test was selected as an appropriate means to assess the adrenergic system function. Our results demonstrate that (a) all chagasics respond with a significantly smaller rise in diastolic blood pressure (0-3.8 mmHg) than normal subjects (9-12 mmHg), when submitted to the tilting test and (b) chagasic patients with heart failure have a significantly lower heart rate than normal subjects and nonchagasic heart failure patients (P < 0.05 and 0.001, respectively). With these results we may speculate that the damage in chronic Chagas' disease should be located in the sympathetic pathway. Therefore, the faulty orthostatic mechanism would be the consequence of a diminished adrenergic activity, with a defective arteriolar vasoconstriction and a decreased basal heart rate. At the same time we note that our results differ from the results of similar tests performed on the same kind of chagasic patients in Brazil, where a predominantly decreased parasymphathetic activity has been demonstrated.
