Primer choque apropiado del desfibrilador automático implantable en pacientes con cardiopatía chagásica

Objetives:

To assess if patients with Chagasic heart disease (CHD) received effective automatic implantable defibrillator (AID) shocks earlier than patients with ischemic heart disease (IHD).

Methods:

Retrospective cohort of patients with CHD and IHD who received an implantable cardioverter defibrillator (ICD) between 2009 and 2018, in a tertiary hospital. We evaluated the time between the implant of ICD and the first effective shock in patients with CHD and compared it with the IHD control population.

Results:

We included a total of 64 patients, 20 with CHD and 44 with IHD. CHD patients presented earlier an effective shock than patients with IHD during the first year (hazard ratio [HR]: 8.4; 95% confidence interval [95% CI]: 2.09-34.02; p = 0.0027), and at three years (HR: 4.61; 95% CI: 1.51-14.07; p = 0.0072). 100% of CHD patients who received the ICD as secondary prevention of sudden cardiac death presented an effective shock during the first 26 months of follow-up.

Conclusions:

Patients with CHD received effective ICD shocks earlier than the IHD patients. All patients with CHD and ICD as secondary prevention had an appropriate ICD shock at short term, representing the highest risk population, and supporting the indication of the device in a setting where randomized clinical trials are lacking.     

Infection with Schistosoma mansoni correlates with altered immune responses to Ascaris lumbricoides and hookworm

Studies were performed on humoral and cellular immune responses of patients from areas in Brazil endemic for hookworm and Ascaris lumbricoides, and either endemic or non-endemic for Schistosoma mansoni. Humoral and cellular responses were evaluated by enzyme-linked immunosorbant assay (ELISA) and peripheral blood mononuclear cell (PBMC) proliferation assays against larval hookworm antigens, A. lumbricoides egg antigens, and soluble egg antigens (SEA) or soluble whole adult antigenic preparation (SWAP) from S. mansoni. Patients from S. mansoni-endemic areas, who currently had only hookworm or Ascaris infections, expressed lower humoral and cellular responses to hookworm or Ascaris antigens, respectively, than did their counterparts from areas not endemic for S. mansoni. Individuals from S. mansoni endemic area, although without detectable S. mansoni infection, do mount humoral and cellular responses to SEA and SWAP. This group of individuals has been probably in contact with S. mansoni antigens, since the groups harboring A. lumbricoides or hookworm infections from non-S. mansoni endemic areas do not have detectable anti-S. mansoni responses. PBMC proliferative responses discriminated well between patients with active hookworm infections versus ascariasis, if they were from areas not endemic for S. mansoni.     

Cardiac manifestations of parasitic infections. Part 2: Parasitic myocardial disease

This is part two of a three‐part series discussing parasites of the heart. In this section, we present an overview on parasitic diseases predominantly involving the myocardium. Copyright © 2007 Wiley Periodicals, Inc.     

Cardiac manifestations of parasitic infections part 3: pericardial and miscellaneous cardiopulmonary manifestations

This is part three of a three-part series discussing parasites of the heart. In this section, we present an overview on parasitic diseases involving predominantly the pericardium and other miscellaneous cardiopulmonary manifestations such as some pulmonary hypertension syndromes and endomyocardial fibrosis.     

Cardiac manifestations of parasitic infections part 1: overview and immunopathogenesis

Parasitic infections produce a wide spectrum of cardiac manifestations. They may involve various anatomic structures of the heart and are manifested clinically as myocarditis, cardiomyopathies, pericarditis, or pulmonary hypertension in many resource-constrained settings. However, many parasitic infections involving the heart may also be currently diagnosed in developed countries due to growing worldwide travel, blood transfusions, and increasing numbers of immunosuppression states such as organ transplantation, use of immunosuppressive agents, or HIV/AIDS. Clinicians anywhere in the globe need to be aware of the potential cardiac manifestations of parasitic diseases. This is part one of a three-part series discussing parasites of the heart. In this section, we provide a general overview and immunopathogenesis of parasitic infections of the heart.     

Precordial chest pain in patients with chronic Chagas disease

Precordial chest pain affects about 15% to 33% of patients with chronic Chagas disease. In the absence of megaesophagus, it should be ascribed to chronic Chagas heart disease. Precordial chest pain is atypical because it can usually neither be associated to physical exercise nor be alleviated by nitroglycerin. However, in certain circumstances, precordial chest pain can masquerade as acute coronary syndrome. Although obstructive coronary artery disease can occasionally be found, microvascular angina seems to be the mechanism behind such phenomenon. Precordial chest pain not always has a benign clinical course; sometimes, it can herald a dismal prognosis. On the basis of cases previously reported, it seems that nitrates, betablockers and/or calcium channel blockers can be of value in the treatment of this condition.     

Abnormalities in Fractal Heart Rate Dynamics in Chagas Disease

Background and Methods: In order to study fractal HR dynamics in Chagas disease, we performed detrended fluctuation analysis (DFA)—along with analysis of power‐law β slope (β index) and standard deviation of N–N intervals (SDNN)—in edited and unedited (with ventricular premature beats — VPBs, only in DFA analysis) series of R‐R intervals from Holter monitoring of healthy controls (Group 0, n = 27) and Chagas disease patients with left ventricular (LV) ejection fraction >50% (Group 1, n = 137) and with LV ejection fraction <50% (Group 2, n = 23). Results: When analyzed from the edited R‐R interval data, the long‐term scaling exponent α₂ is altered both among the Chagas patients with and without LV dysfunction. The short‐term scaling exponent α₁ was higher in Group 1 Chagas patients as compared to controls (P < 0.01) and did not differ between Group 2 and controls. In unedited R‐R interval series, α₁ was significantly reduced in Group 2 Chagas patients (0.55 ± 0.002) as compared to controls (0.90 ± 0.002) and Group 1 (0.91 ± 0.003) (P < 0.001), but did not differ between Group 1 and controls. Similarly α₂ was lower in Group 2 compared to other groups (P < 0.001). SDNN did not differ between the groups, but the β index derived from 1/f model was reduced both in Group 1 and 2 Chagas patients as compared to controls (P < 0.01). There was strong correlation (rs = 0.82; P < 0.001) between the β and α₂ index from edited series. There was an inverse correlation (rs =?0.63, P < 0.01) between the number of VPBs and α₁ index of unedited series. Conclusions: The long‐term fractal HR dynamics altered in chagasic patients with and without LV dysfunction could be an early sign of autonomic dysfunction. Patients with impaired LV function show marked alterations in short‐term fractal HR dynamics toward more random behavior, mainly due to frequent ectopy. Prospective studies are necessary to define the value of these indices as predictors of death in Chagas disease.     

Heart rate turbulence and left ventricular ejection fraction in Chagas disease.

AIMS: Chagas disease patients often present premature ventricular complexes (PVCs), depression of left ventricular ejection fraction (LVEF) and autonomic dysfunction, which is generally evaluated by heart rate variability (HRV) analysis. As frequent PVCs may complicate HRV computation, we measured heart rate turbulence (HRT) and evaluated the correlation between ejection fraction and HRT or HRV in Chagas disease. METHODS: We studied 30 patients (47+/-11 years, 20 men) with Chagas cardiomyopathy and left ventricular dilatation who underwent clinical evaluation, ejection fraction (EF: 45+/-14%) determination and 24-h Holter monitoring (median PVC=1781). In all patients, the standard deviation of normal RR intervals (SDNN), the square root of the mean square differences of successive RR intervals (RMSSD) and values of turbulence onset (TO) and turbulence slope (TS) were calculated. RESULTS: HRT indices were independent of mean RR interval and presented high correlation with EF: TO (-0.11+/-0.01%, r=-0.60, P<0.001) and TS (5.8+/-3.7 ms/RR-interval, r=0.73, P<0.001). Of HRV parameters, only SDNN, corrected for mean RR interval, showed a weak but not significant correlation with EF (r=0.41). The comparison of HRT/EF and HRV/EF correlation coefficients, indicated the presence of a significant difference (P=0.017). CONCLUSIONS: HRT indices appear to correlate better with EF than SDNN in Chagas disease. Thus, an analysis based on heart rate transient adaptation seems to perform better than HRV in detecting the autonomic alterations that parallel left ventricular dysfunction in Chagas disease patients. The high number of PVCs observed in these patients further support the use of HRT methodology.     

Chronotropic Incompetence and Abnormal Autonomic Modulation in Ambulatory Chagas Disease Patients

Background: Chagas disease (ChD) patients might present chronotropic incompetence during exercise, although its physiopathology remains uncertain. We evaluated the heart rate (HR) response to exercise testing in ChD patients in order to determine the role of autonomic modulation and left ventricular dysfunction in the physiopathology of chronotropic incompetence. Methods: ChD ambulatory patients (n = 170) and healthy controls (n = 24) underwent a standardized protocol including Doppler echocardiography, Holter monitoring, HR variability analysis, brain natriuretic peptide (BNP) measurement, and maximal exercise testing. The chronotropic response was calculated as the percentage of predicted HR achieved and the HR increment (ΔHR) during exercise. ChD patients were divided according to the absence or presence of cardiopathy and chronotropic incompetence (<85% predicted HR). Results: Chronotropic incompetence was present in 34 (20%) of all ChD patients. The group with cardiopathy displayed reduced ΔHR (91 ± 19 bpm) during exercise in comparison with ChD patients without cardiopathy (100 ± 19 bpm). Both the values observed in ChD groups were significantly different from those of controls (112 ± 13 bpm). Exercise duration, maximal oxygen consumption, and systolic blood pressure increment were significantly reduced in patients with abnormal chronotropic response. ΔHR during the exercise was significantly correlated with markers of autonomic control of sinus node, such as rest HR (r =?0.498, P ≤ 0.001), peak HR during exercise (r = 0.775, P ≤ 0.001), minimal HR during Holter recording (r =?0.231, P = 0.003), and high‐ and low‐frequency components of short‐term HR variability (r = 0.188, P = 0.042 and r = 0.203, P = 0.027). Neither left ventricular function nor BNP levels were independently related to the presence of chronotropic incompetence. Conclusions: Chronotropic incompetence may be considered an early sign of autonomic dysfunction in ChD patients.     

Prevalence of Trypanosoma cruzi/HIV coinfection in southern Brazil

Chagas disease reactivation has been a defining condition for acquired immune deficiency syndrome in Brazil for individuals coinfected with Trypanosoma cruzi and HIV since 2004. Although the first coinfection case was reported in the 1980s, its prevalence has not been firmly established. In order to know coinfection prevalence, a cross-sectional study of 200 HIV patients was performed between January and July 2013 in the city of Pelotas, in southern Rio Grande do Sul, an endemic area for Chagas disease. Ten subjects were found positive for T. cruzi infection by chemiluminescence microparticle immunoassay and indirect immunofluorescence. The survey showed 5% coinfection prevalence among HIV patients (95% CI: 2.0–8.0), which was 3.8 times as high as that estimated by the Ministry of Health of Brazil. Six individuals had a viral load higher than 100,000 copies per μL, a statistically significant difference for T. cruzi presence. These findings highlight the importance of screening HIV patients from Chagas disease endemic areas.     

Rare Association: Chagas' Disease and Hypertrophic Cardiomyopathy

A woman (49 years) with Chagas’ disease showed: ECG, right bundle‐branch block and left anterior–superior fascicular block; V₁ has unusual R > R’, and elevated ST segment from V₂ to V₆. Additional imaging revealed concomitant HCM and Chagas, which is uncommon. Overlapping of ECG findings can be explained by this rare association of diseases.     

Echocardiographic Parameters and Survival in Chagas Heart Disease with Severe Systolic Dysfunction

Background

Echocardiography provides important information on the cardiac evaluation of patients with heart failure. The identification of echocardiographic parameters in severe Chagas heart disease would help implement treatment and assess prognosis.

Objective

To correlate echocardiographic parameters with the endpoint cardiovascular mortality in patients with ejection fraction < 35%.

Methods

Study with retrospective analysis of pre-specified echocardiographic parameters prospectively collected from 60 patients included in the Multicenter Randomized Trial of Cell Therapy in Patients with Heart Diseases (Estudo Multicêntrico Randomizado de Terapia Celular em Cardiopatias) - Chagas heart disease arm. The following parameters were collected: left ventricular systolic and diastolic diameters and volumes; ejection fraction; left atrial diameter; left atrial volume; indexed left atrial volume; systolic pulmonary artery pressure; integral of the aortic flow velocity; myocardial performance index; rate of increase of left ventricular pressure; isovolumic relaxation time; E, A, Em, Am and Sm wave velocities; E wave deceleration time; E/A and E/Em ratios; and mitral regurgitation.

Results

In the mean 24.18-month follow-up, 27 patients died. The mean ejection fraction was 26.6 ± 5.34%. In the multivariate analysis, the parameters ejection fraction (HR = 1.114; p = 0.3704), indexed left atrial volume (HR = 1.033; p < 0.0001) and E/Em ratio (HR = 0.95; p = 0.1261) were excluded. The indexed left atrial volume was an independent predictor in relation to the endpoint, and values > 70.71 mL/m² were associated with a significant increase in mortality (log rank p < 0.0001).

Conclusion

The indexed left atrial volume was the only independent predictor of mortality in this population of Chagasic patients with severe systolic dysfunction.     

T-wave amplitude variability and the risk of death in Chagas disease

T‐Wave Amplitude Variability in Chagas Disease. Introduction: Measurement of beat‐to‐beat T‐wave amplitude variability (TWV) has been described as a promising new technique for the stratification of arrhythmic risk in postmyocardial infarction and dilated cardiomyopathy patients. Chagas disease (ChD) can lead to a potentially lethal cardiopathy that can present with ventricular arrhythmias, heart blocks, heart failure, and sudden death. The aim of the study was to evaluate the prognostic value of TWV in ChD patients in addition to traditional prognostic predictors. Methods and Results: The study enrolled 113 ambulatory ChD patients (62 men; age: 42 ± 9 years) in sinus rhythm and without other systemic diseases, evaluated by a standard clinical protocol. We computed TWV in 10‐minute ECG recordings obtained in controlled resting conditions. TWV was defined as the median values among 8 consecutive 50‐ms T‐wave segments and dichotomized as either ≤ or > 30 μV². The association of TWV and death was evaluated by Cox proportional‐hazards analysis, considering other established predictors. During mean follow‐up time of 106 ± 28 months, 14 patients died. A value of median TWV > 30 μV² predicts increased risk of death in a multivariate analysis (HR = 5.76, 95% CI 1.31–25.23, P = 0.014), in addition to depressed left ventricular function, presence of nonsustained ventricular tachycardia and QRS duration >133 ms. Conclusion: Repolarization variability, evaluated by TWV, is independently related to the risk of death in ChD. This noninvasive methodology could facilitate the identification of patients who may benefit from more aggressive therapeutic strategies. (J Cardiovasc Electrophysiol, Vol. 22, pp. 799‐805, July 2011)