ABC | Volume 113, Nº4, October 2019

Case Report Farias et al. Myocarditis due to Chikungunya/Dengue coinfection Arq Bras Cardiol. 2019; 113(4):783-786 Discussion Typical clinical manifestations of acute CHIKV infection are fever, headache, polyarthralgia/polyarthritis, myalgia, rash, and fatigue. 11 Atypical manifestations have also been described, affecting the cardiovascular, nervous, ocular, cutaneous, and other systems. 6,12-14 The clinical spectrum of chikungunya heart disease ranges from asymptomatic ECG alterations to potentially lethal cardiac complications. 6 The manifestations of acute DENV infection are very similar to those of CHIKV, with a lower prevalence for joint manifestations. 15 Heart involvement in DENV infection is not uncommon. Cardiac manifestations can vary widely, from silent disease to severe myocarditis resulting in death. 7 Arora et al. 7 studying 120 patients with DENV found 37.5% of patients with cardiac manifestation in the form of myocarditis and 5% with rhythm disturbance, with AV block being the most common. 16 The specific viral diagnosis is commonly made through ELISA, a specific serological test. 11,15 In cases of DENV, secretion of the NS1 non-structural viral protein from infected cells makes an early diagnosis possible. NS1 protein can be detected in blood and tissue samples within 9 days of the onset of fever. 15 There is a low probability that the patient had an isolated viral infection since both viruses are part of different viral families, thus considerably reducing the cross-reaction probability. Kam et al. 17 found that 6% of DENV-infected patients had antibodies that were cross-reactive to CHIKV. 17 Although they share the same vector, CHIKV is part of the Togaviridae family, while DENV is part of the Flaviviridae family. Heart disease associated with arboviruses has no specific treatment and may be a self-limited condition. Thus, quick supportive therapy to prevent further cardiac function Figure 1 – Transthoracic echocardiogram with altered left ventricular ejection fraction (36.39%), left ventricular hypercontractility, and mild bilateral pericardial effusion (A‑D). E-H shows a second transthoracic echocardiogram with ejection fraction of 70%. DP and LP: pericardial effusion. RV: right ventricle; LV: left ventricle; RA: right atrium; LA: left atrium; EF: ejection fraction. 784