Evaluation of the six-minute walk test in patients with chronic heart failure associated with Chagas' disease and systemic arterial hypertension

INTRODUCTION: To evaluate physical capacity as determined by the six-minute walk test (6MWT) in patients with chronic heart failure due to Chagas' disease associated with systemic arterial hypertension (Chagas-SAH). METHODS: A total of 98 patients routinely followed at the Cardiomyopathy Outpatient Service were recruited. Of these, 60 (61%) were diagnosed with Chagas disease and 38 (39%) with Chagas-SAH. RESULTS: The distance walked during 6 min was 357.9 ±98 m for Chagas-SAH patients and 395.8 ± 121m for Chagas cardiomyopathy patients (p >0.05). In patients with Chagas-SAH, a negative correlation occurred between the 6MWT and the total score of the Minnesota Living with Heart Failure Questionnaire (r= -0.51; p=0.001). No other correlations were determined between 6MWT values and continuous variables in patients with Chagas-SAH. CONCLUSIONS: The results of the 6MWT in Chagas-SAH patients are similar to those verified in Chagas cardiomyopathy patients with chronic heart failure. Coexistence of SAH does not seem to affect the functional capacity of Chagas cardiomyopathy patients with chronic heart failure.

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.

Prevalence of Trypanosoma cruzi antibodies and inflammatory markers in uncompensated heart failure

INTRODUCTION: Heart failure (HF) represents the final stage of chronic chagasic cardiomyopathy (CChC). The diagnosis of CChC is based on the demonstration of anti-Trypanosoma cruzi antibodies (aTcAg) and clinical and epidemiological data. In Venezuela, there are no data about the prevalence of chagasic HF. The aim of this study was to determine the epidemiological, clinical, and inflammatory risk factors associated with seronegative or seropositive HF patients. METHODS: We performed a cross-sectional study in the Venezuelan central-west states among a healthy rural population and in patients admitted to the emergency room with uncompensated HF. RESULTS: The seroprevalence rates of Trypanosoma cruzi antibodies were 11.2% and 40.1% in the healthy population and in HF patients, respectively. Seropositivity in healthy individuals was associated with age, knowledge on triatomine vectors, and having seen wild reservoirs in the house; in HF patients, with contact with the vector and previous clinical diagnosis of Chagas' disease; and in both groups taken together, with age, knowledge on triatomines, and HF. Seropositive patients had prolonged QRS, decreased ejection fraction, and high serum magnesium, all significant as compared with HF seronegative cases. Left atrium enlargement and ventricular hypertrophy were most frequently observed in HF seronegative patients. CRP, IL6, ILβ1, IL2, and FNTα were elevated in 94.5%, 48%, 17.8%, 13.7%, and 6.9% of HF patients, respectively, but only IL2 levels were associated with chagasic HF. CONCLUSIONS: There is a high prevalence of aTcAg in HF patients from the central-west region of Venezuela, and their epidemiological, clinical, and inflammatory features are discreetly different as compared with those of seronegative cases.

Is autonomic function associated with left ventricular systolic function in Chagas heart disease patients undergoing treatment for heart failure?

Introduction The association between cardiac autonomic and left ventricular (LV) dysfunction in Chagas disease (ChD) is controversial. Methods A standardized protocol that includes the Valsalva maneuver, a respiratory sinus arrhythmia (RSA) test, and an echocardiographic examination was used. Spearman correlation coefficients (rho) were used to investigate associations. Results The study population consisted of 118 ChD patients undergoing current medical treatment, with an average LV ejection fraction of 51.4±2.6%. The LV ejection fraction and diastolic dimension were correlated with the Valsalva index (rho=0.358, p<0.001 and rho=-0.266, p=0.004, respectively) and the RSA (rho=0.391, p<0.001 and rho=-0.311, p<0.001, respectively). Conclusions The impairment of LV function is directly associated with a reduction of cardiac autonomic modulation in ChD.

An unusual case of heart failure due to Plasmodium vivax infection with a favorable outcome

Although malaria is one of the oldest types of parasitic infection, we have recently witnessed substantial changes in the outcome of malarial infections. Severe Plasmodium vivax infections have recently become more frequent, and are occasionally associated with fatal outcomes. Cardiac arrhythmia and myocardial failure have also been reported, typically in association with Plasmodium falciparum infections. We report a case of myocarditis and heart failure, due to Plasmodium vivaxinfection, along with the favorable outcome.

Pouchitis: extracolonic manifestation of ulcerative colitis?

Pouchitis is the most frequent complication of ileal pouch-anal anastomosis for treatment of ulcerative colitis. There are several possible explanations. Among them, we focus on the one that considers pouchitis as an extracolonic manifestation of ulcerative colitis. The aim of this study was to investigate the association between pouchitis and extra-intestinal manifestations (EIM), which are frequent in these patients. Sixty patients underwent restorative proctocolectomy with an ileal J pouch (IPAA) from September 1984 to December 1998. Pouchitis was defined by clinical, endoscopic, and histologic criteria. The following extra-intestinal manifestations were studied: articular, cutaneous, hepatobiliary, ocular, genitourinary, and growth failure. Thirteen patients, of which 10 were female (76.9%), developed one or more episodes of pouchitis. Twelve patients of this group (92.3%) presented some kind of extra-intestinal manifestation, 4 pre-operatively (exclusively), 2 post-operatively (exclusively), and 6 both pre- and post-operatively (1.7 per patient). Twenty patients (42.7%) of the 47 without pouchitis did not present extra-intestinal manifestations; 10/35 (28.5%) of females had pouchitis, compared to 3/35 (12.0%) of men. Pouchitis was more frequent among females, though not statistically significant. EIM increases the risk of pouchitis. Pouchitis is related to EIM in 92.3 % of cases, corroborating the hypothesis that it could be an extracolonic manifestation of ulcerative colitis.

Acute renal failure due to abdominal compartment syndrome: report on four cases and literature review

We report on 4 cases of abdominal compartment syndrome complicated by acute renal failure that were promptly reversed by different abdominal decompression methods. Case 1: A 57-year-old obese woman in the post-operative period after giant incisional hernia correction with an intra-abdominal pressure of 24 mm Hg. She was sedated and curarized, and the intra-abdominal pressure fell to 15 mm Hg. Case 2: A 73-year-old woman with acute inflammatory abdomen was undergoing exploratory laparotomy when a hypertensive pneumoperitoneum was noticed. During the surgery, enhancement of urinary output was observed. Case 3: An 18-year-old man who underwent hepatectomy and developed coagulopathy and hepatic bleeding that required abdominal packing, developed oliguria with a transvesical intra-abdominal pressure of 22 mm Hg. During reoperation, the compresses were removed with a prompt improvement in urinary flow. Case 4: A 46-year-old man with hepatic cirrhosis was admitted after incisional hernia repair with intra-abdominal pressure of 16 mm Hg. After paracentesis, the intra-abdominal pressure fell to 11 mm Hg.

Evidence for a stress hypothesis: hemiparasitism effect on the colonization of Alchornea castaneaefolia A. Juss.uphorbiaceae) by Galling Insects

Stressed plants are generally more attacked by galling insects. In this study we investigated the relationship between population abundance and species richness of galling insects on the tree Alchornea castaneaefolia A. JUSS. (Euphorbiaceae), submited to stress induced by the hemiparasite Psittacanthus sp. (Loranthaceae) in the Amazon, Brazil. Branches of A. castaneaefolia attacked by the hemiparasite were more heavily infested by galling insects than non-attacked branches. The field observations partially corroborate the hypothesis that there would be an optimal level of host-plant stress for galling insect establishment.

Does nitrogen availability have greater control over the formation of tropical heath forests than water stress?A hypothesis based on nitrogen isotope ratios

Global scale analyses of soil and foliage δ15N have found positive relationships between δ15N and ecosystem N loss (suggesting an open N cycle) and a negative relationship between δ15N and water availability. We show here that soils and leaves from tropical heath forests are depleted in 15N relative to 'typical' forests suggesting that they have a tight N cycle and are therefore limited by N rather than by, often suggested, water availability.

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.

Effects of propranolol on the QT dispersion in congestive heart failure

OBJECTIVE - Studies have shown that therapy with beta-blockers reduces mortality in patients with heart failure. However, there are no studies describing the effects of propranolol on the QT dispersion in this population. The objective of this study was to assess the electrophysiological profile, mainly QT dispersion, of patients with heart failure regularly using propranolol. METHODS - Fifteen patients with heart failure and using propranolol were assessed over a period of 12 months. Twelve-lead electrocardiograms (ECG) were recorded prior to the onset of beta-blocker therapy and after 3 months of drug use. RESULTS - A significant reduction in heart rate, in QT dispersion and in QTc dispersion was observed, as was also an increase in the PR interval and in the QT interval, after the use of propranolol in an average dosage of 100 mg/day. CONCLUSION - Reduction in QT dispersion in patients with heart failure using propranolol may explain the reduction in the risk of sudden cardiac death with beta-blocker therapy, in this specific group of patients.

Exercise and heart failure. Relation of the severity of the disease to the anaerobic threshold and the respiratory compensation point

OBJECTIVE - To identify, the anaerobic threshold and respiratory compensation point in patients with heart failure. METHODS - The study comprised 42 Men,divided according to the functional class (FC) as follows: group I (GI) - 15 patients in FC I; group II (GII) - 15 patients in FC II; and group III (GIII) - 12 patients in FC III. Patients underwent a treadmill cardiopulmonary exercise test, where the expired gases were analyzed. RESULTS - The values for the heart rate (in bpm) at the anaerobic threshold were the following: GI, 122±27; GII, 117±17; GIII, 114±22. At the respiratory compensation point, the heart rates (in bpm) were as follows: GI, 145±33; GII, 133±14; GIII 123±22. The values for the heart rates at the respiratory compensation point in GI and GIII showed statistical difference. The values of oxygen consumption (VO2) at the anaerobic threshold were the following (in ml/kg/min): GI, 13.6±3.25; GII, 10.77±1.89; GIII, 8.7±1.44 and, at the respiratory compensation point, they were as follows: GI, 19.1±2.2; GII, 14.22±2.63; GIII, 10.27±1.85. CONCLUSION - Patients with stable functional class I, II, and III heart failure reached the anaerobic threshold and the respiratory compensation point at different levels of oxygen consumption and heart rate. The role played by these thresholds in physical activity for this group of patients needs to be better clarified.