Functional Capacity of Patients with Pacemaker Due to Isolated Congenital Atrioventricular Block

Background:Isolated congenital atrioventricular block (CAVB) is a rare condition with multiple clinical outcomes. Ventricular remodeling can occur in approximately 10% of the patients after pacemaker (PM) implantation.Objectives:To assess the functional capacity of children and young adults with isolated CAVB and chronic pacing of the right ventricle (RV) and evaluate its correlation with predictors of ventricular remodeling.Methods:This cross-sectional study used a cohort of patients with isolated CAVB and RV pacing for over a year. The subjects underwent clinical and echocardiographic evaluation. Functional capacity was assessed using the six-minute walk test. Chi-square test, Fisher's exact test, and Pearson correlation coefficient were used, considering a significance level of 5%.Results:A total of 61 individuals were evaluated between March 2010 and December 2013, of which 67.2% were women, aged between 7 and 41 years, who were using PMs for 13.5 ± 6.3 years. The percentage of ventricular pacing was 97.9 ± 4.1%, and the duration of the paced QRS complex was 153.7 ± 19.1 ms. Majority of the subjects (95.1%) were asymptomatic and did not use any medication. The mean distance walked was 546.9 ± 76.2 meters and was strongly correlated with the predicted distance (r = 0.907, p = 0.001) but not with risk factors for ventricular remodeling. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0)Conclusions:The functional capacity of isolated CAVB patients with chronic RV pacing was satisfactory but did not correlate with risk factors for ventricular remodeling.

Electrical Properties of Isolated Cardiomyocytes in a Rat Model of Thiamine Deficiency

In modern society, thiamine deficiency (TD) remains an important medical condition linked to altered cardiac function. There have been contradictory reports about the impact of TD on heart physiology, especially in the context of cardiac excitability. In order to address this particular question, we used a TD rat model and patch-clamp technique to investigate the electrical properties of isolated cardiomyocytes from epicardium and endocardium. Neither cell type showed substantial differences on the action potential waveform and transient outward potassium current. Based on our results we can conclude that TD does not induce major electrical remodeling in isolated cardiac myocytes in either endocardium or epicardium cells.

Spectrum of cardiac lesions associated with Isolated Cleft Mitral Valve and their impact on therapeutic choices

Abstract Background: Isolated cleft mitral valve (ICMV) may occur alone or in association with other congenital heart lesions. The aim of this study was to describe the profile of cardiac lesions associated with ICMV and their potential impact on therapeutic management. Methods: We conducted a descriptive study with data retrieved from the Congenital Heart Disease (CHD) single-center registry of our institution, including patients with ICMV registered between December 2008 and November 2014. Results: Among 2177 patients retrieved from the CHD registry, 22 (1%) had ICMV. Median age at diagnosis was 5 years (6 days to 36 years). Nine patients (40.9%) had Down syndrome. Seventeen patients (77.3%) had associated lesions, including 11 (64.7%) with accessory chordae in the left ventricular outflow tract (LVOT) with no obstruction, 15 (88.2%) had ventricular septal defect (VSD), three had secundum atrial septal defect, and four had patent ductus arteriosus. Thirteen patients (59.1%) required surgical repair. The decision to proceed with surgery was mainly based on the severity of the associated lesion in eight patients (61.5%) and on the severity of the mitral regurgitation in four patients (30.8%). In one patient, surgery was decided based on the severity of both the associated lesion and mitral regurgitation. Conclusion: Our study shows that ICMV is rare and strongly associated with Down syndrome. The most common associated cardiac abnormalities were VSD and accessory chordae in the LVOT. We conclude that cardiac lesions associated with ICMV are of major interest, since in this study patients with cardiac lesions were diagnosed earlier. The decision to operate on these patients must take into account the severity of both mitral regurgitation and associated cardiac lesions.

Two new serovars of Salmonella: S. Natal and S. potengi, isolated from fluvial water in Natal, Rio Grande do Norte State, Brazil

Two new serovars of Salmonella from estuary waters of potengi river in Natal, Rio Grande do Norte, were isolated. They were named S. natal (9,12: z4, z24:-) and S. potengi (18;z: -). Both types belong to the subgenus I, or subspecies 1, thought they showed atypical behaviour (KCN +).

The susceptibility of wild caught sand flies to infection by a subspecies of Leishmania mexicana isolated from proechimys iheringi denigratus (Rodentia, echimyidae)

Several species of wild caught sand flies were collected in the same site where a subspecies of leishmania mexicana was isolated from the rodent Proechimys iheringi denigratus. The absence of natural infection in these sand flies permitted us to test, with relative assurance, the susceptibility of wild caught females to infection by this parasite. the success obtained in these experimental infections suggest that one or more of the sand fly species encountered in high numbers in the same site where the infected rodents were captured may be the vector(s) of this subspecies of l. mexicana.

Colicinogeny in Salmonella serovars isolated in Brazil

A study of colicinogeny was made in 748 strains of Salmonella (97 serovars) isolated from different sources; human (291), animal (119), environmental (141), food (102) and animal feed (95). Colicin production was detected in 64 strains (8.6%), particularly isolated from foods (30.4%). Col. E1 (53) and Ia (44) were the most frequently observed, especially in S. agona for environment and food sources. Col V production was identified in 5 strains of S. typhimurium within 8 producer cultures isolated from humans. Its relationship with the sources and serovars of Salmonella are discussed.

Serotyping of Candida albicans isolated from clinical specimens

A specific antiserum to Candida albicans serotype A was prepared adsorbing a total antiserum with Candida albicans serotype B cells. This specific antiserum was used for serotyping C. albicans strains obtained from patients in different hospitals of Havana City, Cuba. Two hundred strains (95.2%) were serotype A, the remaining 10 (4.8%) were serotype B. Results were also correlated with strains isolated from the specimen origin, sex and race of the patient. The usefulness of this specific antiserum to determine C. albicans serotypes and its therapeutic value are pointed out.

Trypanosoma rangeli (Tejera, 1920) isolated from a sylvatic rodent (Echimys dasythrix) in Santa Catarina island, Santa Catarina state: first report of this trypanosome in southern Brazil

A trypanosome strain isolated from a sylvatic rodent (Echimys dasythrix) from Santa Catarina Island (Santa Catarina State, Brazil) was characterized by the following methods: experimental transmission and development in invertebrate hosts, morphometry, cross protection, complement sensitivity, lectin agglutination and isoenzyme profiles. Comparasions were made with standard Trypanosoma cruzi and T. rangeli strains. All methods except isoenzyne analysis led to the identification of the isolate as T. rangeli. The isoenzyme differences found could be explained on the basis of polymorphism. Therefore this is the first report of T. rangeli in southern Brazil, increasing the geographical distribution of this parasite.