Mecanismos arritmogênicos deflagadores de choque em chagásicos portadores de cardioversor-desfibrilador implantável / Arrhythmogenic mechanics triggering shock in patients with Chagas' disease and implantable cardioverter defibrillator

A cardiopatia chagásica crônica (CCC) ainda é um importante problema de saúde pública no Brasil. A principal causa de óbito é a morte súbita por taquiarritmia e o cardioversor-desfibrilador implantável (CDI) tornou-se importante opção terapêutica nessa doença. Objetivos: Identificar os pacientes com CCC, portadores de CDI, que receberam terapia de choque e reconhecer o principal mecanismo arritmogênico deflagrador. Metodologia: Estudo descritivo, retrospectivo, com amostra de 81 pacientes portadores de CDI. Os dados relacionados a eventos arrítmicos e terapias foram obtidos retrospectivamente pela análise dos eletrocardiogramas endocavitários (EGM) de cada paciente. Os resultados foram expressos em valores absolutos, médias e porcentagem, em tabelas e gráficos. Resultados: Foram documentadas terapias apropriadas em 68 (83,9%) pacientes, com um total de 5.336 eventos. Desses, 4.585 (85,9%) foram apenas trem de pulso (ATP) e 741 (14,1%), choques subsequentes ou não à falência do ATP. A taquicardia ventricular monomórfica (TVM) foi a arritmia mais diagnosticada nos EGM, com 4.783 (89,6%) eventos, seguida de taquicardia ventricular polimórfica (TVP) em 480 (8,9%) e fibrilação ventricular (FV) em apenas 63 (1,5%). Conclusões: Demonstrou-se elevada prevalência (83,9%) de pacientes chagásicos portadores de CDI submetidos a terapias por esse dispositivo. Além disso, detectou-se que o principal mecanismo arritmogênico deflagrador de choque foi a TVM na zona de taquicardia rápida, secundária à aceleração da frequência cardíaca após terapia por ATP ineficaz...

Chronic Chagas’ cardiomyopathy remains a major public health problem in Brazil. Tachyarrhythmia is the leading cause of sudden death and the implantable cardioverter defibrillator (ICD) has become an important therapeutic option. Objectives: Identify patients with CCC and ICD who have received shock therapy and identify the main arrhythmogenic mechanism triggering shock in these patients. Method: Retrospective descriptive study, with a sample of 81 patients undergoing CDI implantation from January 2004 to December 2007. Data were obtained retrospectively by analysis of patients’ intracavitary electrocardiograms (iECM). Results were expressed as absolute numbers, mean and percentage values, using tables and graphs. Results: Appropriate therapy was documented in 68 (83.9%) patients, with a total of 5,336 events. Of these, 4,585 (85.9%) were only train of pulse (ATP) and 741 (14.1%) were shocks subsequent or not to failure of ATP. Monomorphic ventricular tachycardia (MVT) was the most frequently diagnosed arrhythmia in the iECGs with 4,783 (89.6%) events, followed by polymorphic ventricular tachycardia (TVP) with 480 (8.9%) and ventricular fibrillation (VF) with only 63 (1.5%). Conclusion: This study demonstrated a high prevalence (83.9%) of chagasic patients receiving ICD therapy. Furthermore, the main arrhythmogenic mechanism triggering shock in these patients was MVT in the zone of fast tachycardia secondary to heart rate acceleration after failure of ATP therapy...

Modos de estimulação (VVIR/DDD) na qualidade de vida de pacientes chagásicos portadores de marcapasso / Stimulation modes (VVIR/DDD) in the quality of life of patients with Chaga's Diasease and pacemaker

Apesar dos benefícios hemodinâmicos do marcapasso (MP) de câmara dupla (DDD) sobre o de câmara única (VVI), sua superioridade com relação à qualidade de vida em pacientes chagásicos ainda é controversa. Objetivo: Comparar o efeito das estimulações DDD e VVIR (câmara única com sensor de frequência) sobre a qua lidade de vida de pacientes chagásicos com bloqueio atrioventricular total (BAVT). Método: Foram estudados alternativamente nos modos DDD e VVIR 16 pacientes com BAVT prévio, subdivididos em dois grupos de oito sujeitos, na 1a fase (DDD x VVIR) e após 2 meses, na 2a fase (VVIR x DDD). Em cada uma das fases, a qualidade de vida foi comparada pelas ferramentas SF-36, que é genérica, e AQUAREL, específica para MP. As variáveis obtidas nos modos DDD e VVIR foram submetidas ao teste de Kolmogorov-Smirnov para comprovação ou não de normalidade. Os dados foram então pareados e submetidos à aplicação do teste T. Os valores de p<0,05 foram considerados significativos. Resultados: Nos dois modos de estimulação (DDD e VVIR), o questionário SF-36 não demonstrou significância estatística nos domínios da capacidade funcional (p=0,253), limitação física (p=0,172), vitalidade (p=0,221) e estado geral (p=0,089). A ferramenta AQUAREL, entretanto, demostrou diferença estatisticamente significativa nos domínios de dispneia (p=0,006) e arritmia (p=0,046), favorável ao modo de estimulação DDD. Conclusão: O AQUAREL, instrumento específico para avaliação da qualidade de vida de portadores de MP, demonstrou a superioridade da estimulação DDD sobre a VVIR, o que não ocorreu com a SF-36.

Abstract: Despite the hemodynamic benefits of the dual chamber (DDD) versus the single chamber (VVI) pacemaker (PM), its superiority in the quality of life of patients with Chagas’ disease is still controversial. Objective: This study aims at comparing the effects of DDD and VVI stimulation on the quality of life of Chagasic patients with third degree atrioventricular (AV) block. Methods: We studied 16 patients with third degree AV block alternatively in DDD/VVIR mode. Patients were subdivided into 2 groups of 8 subjects in the 1st phase (DDDxVVIR) and after 2 months, 2nd Phase (VVIRxDDD). We compared quality of life using the SF-36 questionnaire, which is generic, and the AQUAREL questionnaire, which is specific for PM, in each stage of the study. The values obtained in DDD and VVIR were tested with Kolmogorov-Smirnov grip for confirmation or not of normality. We then matched the data submitted and applied the T test. P values<0.05 were considered significant. Results: SF-36 pacing modes used (VVIR/DDD), showed no statistical significance (p<0.05) in the domains of physical functioning (p=0.253), physical limitations (p=0.172), vitality (p=0.221),general health (p=0.089), social functioning (p=0.172), mental health (p=0.356), however, the AQUAREL tool showed statistically significant differences in the domains of dyspnea (p=0.006) and arrhythmia (p=0.046) in favor of the DDD pacing mode. Conclusion: The AQUAREL questionnaire demonstrated the superiority of DDD pacing over VVI, which was not observed with SF-36.

Use of chitosan membrane associated with polypropylene mesh to prevent peritoneal adhesion in rats.

The correction of wall abdominal defects often requires the use of implants such as polypropylene meshes. In spite of presenting good tissue acceptance, these biomaterials can migrate to adjacent viscera, promote enterocutaneos fistulas, tissue adherence and visceral erosions. In this work, the barrier effect of chitosan films associated with polypropylene meshes on adhesion formation experimentally induced in Wistar rats was evaluated. The animals were divided into two groups with 10 animals each. Animals in the CPP group were implanted with chitosan films associated with polypropylene meshes, whereas the ones in the PP group received only polypropylene meshes. After 8 days, the animals were submitted to euthanasia using CO(2) and a descriptive study focusing adhesion formation, visceral involvement with sutures and mesh peritonization was performed. Also, subimplanted material was collected for histopathology analysis. The results showed that the CPP group presented weak adhesions to the omentum over the stitch knots in eight animals. In all animals, the meshes were peritonized, not allowing their visualization after removing the chitosan films. In the PP group, six animals presented intestinal adhesions to the meshes and, in one of them, hepatic adhesion to the mesh was observed, besides omentum adhesion on more than 50% of the mesh area. The protective effect of chitosan films when sutured over polypropylene meshes, as well as no exacerbation of inflammation associated to the peritoneal lesions was statistically demonstrated. Therefore, chitosan films can indeed minimize the formation of peritoneal adhesions induced by polypropylene meshes in rats.