Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

Propriedades Psicométricas da Versão Portuguesa do Kansas City Cardiomyopathy Questionnaire na Miocardiopatia Dilatada com Insuficiência Cardíaca Congestiva

Several studies have shown that patients with congestive heart failure (CHF) have a compromised health-related quality of life (HRQL), and this, in recent years, has become a primary endpoint when considering the impact of treatment of chronic conditions such as CHF. OBJECTIVES: To evaluate the psychometric properties of the Portuguese version of a new specific instrument to measure HRQL in patients hospitalized for CHF: the Kansas City Cardiomyopathy Questionnaire (KCCQ). METHODS: The KCCQ was applied to a sample of 193 consecutive patients hospitalized for CHF. Of these, 105 repeated the assessment 3 months after admission, with no events during this period. Mean age was 64.4 +/- 12.4 years (21-88), and 72.5% were 72.5% male. CHF was of ischemic etiology in 4% of cases. RESULTS: This version of the KCCQ was subjected to statistical validation, with assessment of reliability and validity, similar to the American version. Reliability was assessed by the internal consistency of the domains and summary scores, which showed similar values of Cronbach alpha (0.50-0.94). Validity was assessed by convergence, sensitivity to differences between groups and sensitivity to changes in clinical condition. We evaluated the convergent validity of all domains related to functionality, through the relationship between them and a measure of functionality, the New York Heart Association (NYHA) classification. Significant correlations were found (p < 0.01) for this measure of functionality i patients with CHF. Analysis of variance between the physical limitation domain, the summary scores and NYHA class was performed and statistically significant differences were found (F = 23.4; F = 36.4; F = 37.4, p = 0.0001) in the ability to discriminate severity of clinical condition. A second evaluation was performed on 105 patients at the 3-month follow-up outpatient appointment, and significant changes were observed in the mean scores of the domains assessed between hospital admission and the clinic appointment (differences from 14.9 to 30.6 on a scale of 0-100), indicating that the domains assessed are sensitive to changes in clinical condition. The correlation between dimensions of quality of life in the KCCQ is moderate, suggesting that the dimensions are independent, supporting the multifactorial nature of HRQL and the suitability of this measure for its evaluation. CONCLUSION: The KCCQ is a valid instrument, sensitive to change and a specific measure of HRQL in a population with dilated cardiomyopathy and CHF.

Dilated Cardiomyopathy. New Therapeutic Approach

Inflammatory reaction has been associated with dilated cardiomyopathy. In this context, cardiac autoantibodies and inflammatory cell infiltration have been studied during the last two decades towards the understanding of their origin and the underlying pathogenic mechanisms. Recent research has increasingly focused on the development of an etiological therapeutic approach. Immunoadsorption has shown to improve clinical, echocardiographic, haemodynamic and laboratory parameters in patients with inflammatory dilated cardiomyopathy. In this article we review recent literature concerning this subject, including classification, pathophysiological mechanisms and therapy.

Chagas disease cardiomyopathy: current concepts of an old disease

Chagas disease continues to be a significant public health problem, as ca. 10 million people are still infected with T. cruzi in Latin America. Decades after primary infection, 30% of individuals can develop a form of chronic inflammatory cardiomyopathy known as Chagas disease cardiomyopathy (CCC). Data from both murine models and human studies support the view that an autoimmune response as well as a parasite-driven immune response involving inflammatory cytokines and chemokines may both play a role in generating the heart lesions leading to CCC. This review aims to summarize recent advances in the understanding of the immunopathogenesis of Chagas disease cardiomyopathy.

SEROPREVALENCE OF T. cruzi INFECTION IN BLOOD DONORS AND CHAGAS CARDIOMYOPATHY IN PATIENTS FROM THE COAL MINING REGION OF COAHUILA, MEXICO

Context and Objective: Chagas disease is considered a worldwide emerging disease; it is endemic in Mexico and the state of Coahuila and is considered of little relevance. The objective of this study was to determine the seroprevalence of T. cruzi infection in blood donors and Chagas cardiomyopathy in patients from the coal mining region of Coahuila, Mexico.Design and Setting: Epidemiological, exploratory and prospective study in a general hospital during the period January to June 2011.Methods: We performed laboratory tests ELISA and indirect hemagglutination in three groups of individuals: 1) asymptomatic voluntary blood donors, 2) patients hospitalized in the cardiology department and 3) patients with dilated cardiomyopathy.Results: There were three levels of seroprevalence: 0.31% in asymptomatic individuals, 1.25% in cardiac patients and in patients with dilated cardiomyopathy in 21.14%.Conclusions: In spite of having detected autochthonous cases of Chagas disease, its importance to local public health remains to be established as well as the details of the dynamics of transmission so that the study is still in progress.

Alcohol Septal Ablation in Obstructive Hypertrophic Cardiomyopathy: Four Years of Experience at a Reference Center

INTRODUCTION: We describe our center's initial experience with alcohol septal ablation (ASA) for the treatment of obstructive hypertrophic cardiomyopathy. The procedure, its indications, results and clinical outcomes will be addressed, as will its current position compared to surgical myectomy. OBJECTIVE: To assess the results of ASA in all patients treated in the first four years of activity at our center. METHODS: We retrospectively studied all consecutive and unselected patients treated by ASA between January 2009 and February 2013. RESULTS: In the first four years of experience 40 patients were treated in our center. In three patients (7.5%) the intervention was repeated. Procedural success was 84%. Minor complications occurred in 7.5%. Two patients received a permanent pacemaker for atrioventricular block (6% of those without previous pacemaker). The major complication rate was 5%. There were no in-hospital deaths; during clinical follow-up (22 ± 14 months) cardiovascular mortality was 2.5% and overall mortality was 5%. DISCUSSION AND CONCLUSION: The results presented reflect the initial experience of our center with ASA. The success rate was high and in line with published results, but with room to improve with better patient selection. ASA was shown to be safe, with a low complication rate and no procedure-related mortality. Our experience confirms ASA as a percutaneous alternative to myectomy for the treatment of symptomatic patients with obstructive hypertrophic cardiomyopathy refractory to medical treatment.

PREDICTIVE FACTORS FOR THE PROGRESSION OF CHRONIC CHAGAS CARDIOMYOPATHY IN PATIENTS WITHOUT LEFT VENTRICULAR DYSFUNCTION

The identification of predictors for the progression of chronic Chagas cardiomyopathy (CCC) is essential to ensure adequate patient management. This study looked into a non-concurrent cohort of 165 CCC patients between 1985 and 2010 for independent predictors for CCC progression. The outcomes were worsening of the CCC scores and the onset of left ventricular dysfunction assessed by means of echo-Doppler cardiography. Patients were analyzed for social, demographic, epidemiologic, clinical and workup-related variables. A descriptive analysis was conducted, followed by survival curves based on univariate (Kaplan-Meier and Cox’s univariate model) and multivariate (Cox regression model) analysis. Patients were followed from two to 20 years (mean: 8.2). Their mean age was 44.8 years (20-77). Comparing both iterations of the study, in the second there was a statistically significant increase in the PR interval and in the QRS duration, despite a reduction in heart rates (Wilcoxon < 0.01). The predictors for CCC progression in the final regression model were male gender (HR = 2.81), Holter monitoring showing pauses equal to or greater than two seconds (HR = 3.02) increased cardiothoracic ratio (HR = 7.87) and time of use of digitalis (HR = 1.41). Patients with multiple predictive factors require stricter follow-up and treatment.

Echocardiographic parameters associated with pulmonary congestion in Chagas cardiomyopathy

INTRODUCTION: Discrepancy between the intensity of pulmonary congestion and the grade of cardiomegaly seems to be a common finding of Chagas cardiomyopathy, in spite of significant systolic dysfunction of the left ventricle. Its mechanism has not been established. The aim of this study was to investigate pulmonary congestion and to analyze if it correlated with Doppler echocardiographic parameters in patients with Chagas dilated cardiomyopathy. METHODS: Fifty-five patients with positive serology tests for Trypanosoma cruzi and Chagas dilated cardiomyopathy were studied. Chest x-rays, Doppler echocardiogram and plasmatic brain natriuretic peptide levels were obtained in all patients. The degree of pulmonary venous vessels changes on chest x-ray was graded using a pulmonary congestion score, and then compared to Doppler echocardiographic parameters. RESULTS: Mean age was 48.5 ± 11.2 years and 29% were women. The majority (95%) of patients were in NYHA functional class I and II. Mild pulmonary congestion by chest x-ray was found in 80% of the patients. In a multivariate analysis, left ventricular ejection fraction, right ventricular TEI index and the color M-mode velocity correlated with the degree of pulmonary congestion. CONCLUSIONS: Pulmonary venous changes on chest x-rays are frequent, but usually mild in patients with Chagas dilated cardiomyopathy. The degree of pulmonary congestion correlates with Doppler echocardiographic left and right ventricular dysfunction and with color M-mode velocity.

Digoxin serum levels in patients with Chagas' cardiomyopathy and heart failure

INTRODUCTION: The purpose of this study was to determine digoxin serum concentrations in patients with Chagas' cardiomyopathy with chronic heart failure, because little is known concerning this laboratory test in patients with this condition. METHODS: This study focuses on 29 (29%) out of 101 patients with chronic heart failure secondary to Chagas' cardiomyopathy receiving digoxin therapy. Digoxin was measured by the immune-enzymatic method. RESULTS: New York Heart Association Functional Class III/IV was noted in 13 (45%) patients. The mean potassium serum level was 4.3± 0.5mEq/L, mean creatinine serum levels 1.4± 0.3dg/100ml, and left ventricular ejection fraction 34.7± 13.8%. The median digoxin serum level was 1.27 (0.55; 1.79)ng/ml. Sixteen (55%) patients had digoxin serum levels higher than 1.0ng/ml. Abnormal digoxin serum levels were verified in 13 (45%) patients. Digoxin serum levels correlated moderately with creatinine serum levels (r = 0.39; p< 0.03) and negatively with sodium serum levels (r= -0.38; p= 0.03). CONCLUSIONS: Digoxin serum concentration should be measured in patients with Chagas' cardiomyopathy with chronic heart failure receiving digoxin therapy due to the potential for digoxin toxicity.

Echocardiographic parameters associated with pulmonary congestion in outpatients with Chagas' cardiomyopathy and non-chagasic cardiomyopathy

INTRODUCTION: Despite significant left ventricular (LV) systolic dysfunction and cardiomegaly, pulmonary congestion does not seem to be a major finding in Chagas' cardiomyopathy (CC). This study sought to identify echocardiographic parameters associated with pulmonary congestion in CC and in dilated cardiomyopathy of other etiologies, such as non-CC (NCC), and to compare pulmonary venous hypertension between the two entities. METHODS: A total of 130 consecutive patients with CC and NCC, with similar echocardiographic characteristics, were assessed using Doppler echocardiography and chest radiography. Pulmonary venous vessel abnormalities were graded using a previously described pulmonary congestion score, and this score was compared with Doppler echocardiographic parameters. RESULTS: NCC patients were older than CC patients (62.4 ± 13.5 × 47.8 ± 11.2, p = 0.00), and there were more male subjects in the CC group (66.2% × 58.5%, p = 0.4). Pulmonary venous hypertension was present in 41 patients in the CC group (63.1%) and in 63 (96.9%) in the NCC group (p = 0.0), the mean lung congestion score being 3.2 ± 2.3 and 5.9 ± 2.6 (p = 0.0), respectively. On linear regression multivariate analysis, the E/e' ratio (β = 0.13; p = 0.0), LV diastolic diameter (β = 0.06; p = 0.06), left atrial diameter (β = 0.51; p = 0.08), and right ventricular (RV) end-diastolic diameter (β = 0.02; p = 0.48) were the variables that correlated with pulmonary congestion in both groups. CONCLUSIONS: Pulmonary congestion was less significant in patients with CC. The degree of LV of systolic and diastolic dysfunction and the RV diameter correlated with pulmonary congestion in both groups. The E/e' ratio was the hallmark of pulmonary congestion in both groups.

Pathogenesis of chronic Chagas cardiomyopathy: the role of coronary microvascular derangements

There is ample experimental and clinical evidence of functional and structural microvascular abnormalities occurring in patients with Chagas cardiomyopathy, possibly due to the inflammatory process and/or autonomic disturbances caused by Trypanosoma cruzi infection. Those microvascular derangements are likely to constitute at least an ancillary factor that potentiates and amplifies the chronic inflammation in myocardial tissue. It is possible to devise appropriate therapeutic interventions aimed at reverting or slowing the progression of the microvascular abnormalities to positively affect the natural history of Chagas cardiomyopathy.

Assessment of inotropic and vasodilating effects of milrinone lactate in patients with dilated cardiomyopathy and severe heart failure

OBJECTIVE: To assess the hemodynamic and vasodilating effects of milrinone lactate (ML) in patients with dilated cardiomyopathy (DCM) and New York Heart Association (NYHA) class III and IV heart failure. METHODS: Twenty patients with DCM and NYHA class III and IV heart failure were studied. The hemodynamic and vasodilating effects of ML, administered intravenously, were evaluated. The following variables were compared before and during drug infusion: cardiac output (CO) and cardiac index (CI); pulmonary capillary wedge pressure (PCWP); mean aortic pressure (MAP); mean pulmonary artery pressure (MPAP); mean right atrial pressure (MRAP); left ventricular systolic and end-diastolic pressures (LVSP and LVEDP, respectively); peak rate of left ventricular pressure rise (dP/dt); systemic vascular resistance (SVR); pulmonary vascular resistance (PVR); and heart rate (HR). RESULTS: All patients showed a significant improvement of the analysed parameters of cardiac performance with an increase of CO and CI; a significant improvement in myocardial contractility (dP/dt) and reduction of the LVEDP; PCWP; PAP; MAP; MRAP; SVR; PVR. Were observed no significant increase in HR occurred. CONCLUSION: Milrinone lactate is an inotropic dilating drug that, when administered intravenously, has beneficial effects on cardiac performance and myocardial contractility. It also promotes reduction of SVR and PVR in patients with DCM and NYHA class III and IV of heart failure.