Real-world assessment of multipolar and point-by-point mapping for premature ventricular contraction ablation.

AIMS: We aimed to assess the acute and midterm efficacy of premature ventricular contraction (PVC) ablation guided by multielectrode and point-by-point (PbP) mapping. METHODS AND RESULTS: This is a retrospective, international multicentre study of consecutive patients referred for PVC ablation in 10 hospital centres from January 2017 to December 2021. Based on the mapping approach, two cohorts were identified: the 'Multipolar group', where a dedicated high-density mapping catheter was employed, and the 'PbP group', where mapping was performed with the ablation catheter. Procedural endpoints, safety, and acute (procedural) and midterm efficacies were assessed. Of the 698 patients included in this study, 592 received activation mapping [46% males, median age of 55 (41-65) years]-248 patients in the Multipolar group and 344 patients in the PbP group. A higher number of activation points [432 (217-843) vs. 95 (42-185), P < 0.001], reduced mapping time (40 ± 38 vs. 61 ± 50 min, P < 0.001), and shorter procedure time (124 ± 60 vs. 143 ± 63 min, P < 0.001) were reported in the Multipolar group. Both groups had high acute success rates (84.7% with Multipolar mapping vs. 81.3% with PbP mapping, P = 0.63), as well as midterm efficacy (83.4% vs. 77.4%, P = 0.08), with no significant differences in the risk of adverse events (6.0% vs. 3.5%, P = 0.24). However, for left-sided PVC ablation specifically, there was a higher midterm efficacy in the Multipolar group (80.7% vs. 69.5%, P = 0.04), with multipolar mapping being an independent predictor of success [adjusted OR = 2.231 (95% CI, 1.476-5.108), P = 0.02]. CONCLUSION: The acute and midterm efficacies of PVC ablation are high with both multipolar and PbP mapping, although the former allows for quicker procedures and may potentially improve the outcomes of left-sided PVC ablation.

The colonization of cartilage by "Trypanosoma cruzi" associated with inflammatory reaction

Objetivo: Avaliar no modelo murino o nível de colonizaçao de cartilagens costais e articulares, assim como os ligamentos pelo Trypanosoma cruzi. Métodos: Estudo histopatológico e histoquímico das cartilagens, ligamentos e musculatura esquelética em camundongos atímicos e eutímicos na fase aguda da doença de Chagas experimental. Resultados: Foi observado que em camundongos jovens, infectados com duas amostras polares de T. cruzi, as cartilagens, os ligamentos, a musculatura esquelética e a medula óssea apresentavam-se altamente colonizados pelo parasito. A colonizaçao do pericôndrio e ligamentos muitas vezes está associada com uma reaçao inflamatória em que predomina um infiltrado mononuclear. A idade é um fator importante na colonizaçao da cartilagem pelo parasito, sendo rara em camundongos adultos. A miosite observada no miocárdio e músculos esqueléticos de camundongos, que apresentam a resposta T-dependente intacta, muitas vezes mostra uma paralisia de membros posteriores. Neste caso, observamos certa freqüência de calcificaçao da fibra muscular demonstrada por testes histoquímicos. Camundongos atímicos (Nude) nao têm miosite nem calcificaçao, porém apresentam carga parasitária em níveis extraordinários na musculatura lisa e estriada. Conclusoes: Os fenômenos de paralisia na fase aguda aparecem com freqüência associados com calcificaçoes observadas na musculatura esquelética e a uma intensa miosite. Os resultados mostraram que estes aspectos da patologia da doença de Chagas experimental estao relacionados com a resposta T-dependente, pois camundongos atímicos nunca apresentaram o quadro acima descrito, apesar da intensa carga parasitária nos tecidos musculares. Cepas polares, quer sejam miotrópica ou reticulotrópicas, estao envolvidas com os fenômenos de paralisia. Os condrócitos sao colonizados pelo T. cruzi, assim como o pericôndrio, o que desencadeia um processo inflamatório local

Preliminary evidence of natural resistance to Mycobacterium bovis (BCG) in lepromatous leprosy

An assay system has been developed based on radiometric quantification of 3H uracil incorporation into viable BCG in the absence or presence of blood monocytes in cultures from untreated lepromatous (LL) or tuberculoid (TT) leprosy patients. 3H Uracil incorporation into BCG was inhibited when the bacilli were cultivated in the presence of blood-derived macrophages in culture for four days, and that inhibition was always greater with macrophages harvested from LL patients compared to TT patients. The reasons for such an observed difference in humans are discussed according to our knowledge obtained in murine models of mycobacterial infections.