ABC | Volume 112, Nº3, March 2019

Original Article Ortiz et al Cardiac evaluation in acute CD Arq Bras Cardiol. 2019; 112(3):240-246 Figure 1 – Geographical distribution of the acute cases evaluated in the state of Amazonas. In parenthesis, the number of patients for each municipality. Cardiac evaluation in Group 2 (post-treatment) The follow up cardiac evaluation was done at least one year after the end of the treatment regimen established. It occurred in a mean period of 15.5 months. It was possible to reevaluate 48 patients with ECG and 25 with TTE. Among the 48 patients that were evaluated with an ECG, 35 were normal in the pre-treatment period, of the 30 (86%) continued with normal results and 5 (14%) presented alterations in the post‑treatment period. Thirteen patients had alterations in ECG before treatment, 9 (69%) of them remained altered and 4 (31%) evolved to a normal ECG. Also, during the pre‑treatment period, 4 (16%) out of the 25 patients reevaluated had abnormalities examined in TTE and all of them evolved completely after treatment (Table 3 and 4). Discussion Case distribution, route of transmission and T. cruzi strain CD in the Brazilian Amazon Region has changed its epidemiological profile in the past several years and most of the cases as being acute and due to oral transmission. A peculiarity of our region is the distance between the municipality of the outbreaks occurrence and the state’s capital, Manaus. Therefore, most patients are unable to travel and get the complete cardiac follow-up. During the period that comprised the study, 2007 to 2015, four outbreaks of six already registered in the Amazonas state with a total of 85 cases reported. All of them somehow associated with oral transmission due to açaí consumption. Most times, individuals don’t present cardiac alterations during the acute phase, thus, it’s thought that our region presents milder symptoms that might be associated with the T. cruzi DTU present in the Brazilian Amazon. We observed that only one patient was diagnosed by an immunological assay (IgM anti- T. cruzi ) while all the others had their diagnosis confirmed by thick blood smear. This can be related to the intense qualification of microscopists and all health professionals working in the Malaria Laboratory at the Tropical Medicine Foundation. Considering that most patients arrive with febrile syndrome mostly suspected to malaria infection, they are constantly being trained for the identification of the protozoan Trypanosoma cruzi which allows improving the surveillance of acute cases of CD in the state. 24 In our study population, we were able to find that among acute cases that had Trypanosoma cruzi strain identified, TcIV was present in patients from outbreaks. This is best described by Monteiro et al. 21 Although TcI and Z3 (TcIII/TcIV) have also been identified in humans, 22 the pathogenicity of these strains is still not well known, but it’s believed to be the cause of low morbidity when compared to endemic areas that present other strain of T. cruzi, TcII. 25 Evaluation of cardiac alterations during the pre-treatment and post-treatment stages Cardiac alterations during acute phase though in small proportion (33%) has highlighted the importance of continuous investigation for chronic chagasic cardiopathy, as it is not certain that treatment with benznidazole can indeed eliminate the chance of the patient not evolving to a chronic condition of the disease. 6,26 Analyzing the demographical variables with the presence of any cardiac alterations due to acute infection by T. cruzi, it is possible to observe a significant statistical result for the Central Amazonas mesoregion (p = 0.020) and the isolated cases (p = 0.044). Although it’s possible to think that the higher frequency of cardiopathy in the Central mesoregion might be 242