Background Dengue fever is a mosquito-borne viral disease whose incidence has increased globally, with Indonesia as hyperendemic. In Indonesia, around 17.4% of febrile cases were due to dengue. Expanded dengue syndrome is a term for dengue fever with atypical manifestations in other organs such as renal, respiratory, and cardiac. Dengue myocarditis remains underdiagnosed and usually has a low risk of heart failure. However, pregnancy increases the risk of expanded dengue syndrome, with the incidence six times higher in pregnant women. Due to limited studies about myocarditis treatment during pregnancy, it is critical to understand the effects of heart drugs and the importance of treatment choices with limited selection during fulminant myocarditis. Case presentation We reported a case of an adult pregnant woman in her second trimester with fulminant myocarditis-associated expanded dengue syndrome based on criteria. The patient suddenly worsened with progressive cardiomegaly and lung edema accompanied by cardiogenic shock. Multidisciplinary treatment management has been given to improve cardiac function and other organs due to dengue by considering the risk and family consent. The patient recovered from myocarditis, and the cardiac size has reduced. Conclusions Fulminant myocarditis is a serious complication of expanded dengue syndrome, and aggressive therapy is required to prevent it. Further investigations and a multidisciplinary system are required to reduce or minimize fetal abnormalities.

Brugada syndrome (BrS) has been described as an inherited cardiac disorder due to gene mutations, which contributes to sudden cardiac death, especially in Southeast Asians. Brugada phenocopy, which has the same pattern caused by etiologies such as metabolic disorder, is potentially reversible and avoids unnecessary implantable medical devices. Case Presentation: We reported a rare case of Brugada phenocopy in a 60-years-old Indonesian male with severe anemia and a history of chronic urinary tract bleeding and hemorrhoid. Brugada phenocopy, widely known as BrS look-alike, has been linked to sodium, potassium, and calcium channel dysfunction. This condition is uncommon and has been related to metabolic conditions such as anemia. Iron deficiency anemia induces ischemia in the myocardium and degrades the calcium channels. During the transfusion, hypocalcemia precipitates temporary arrhythmia with right ventricular outflow tract origin, which reverts after the hypocalcemia has been treated. Conclusion: Due to the possibility of altered ion channels and how rarely hypocalcemia induces arrhythmia, this makes understanding the pathogenesis of Brugada phenocopy essential. Though caution is necessary, early recognition can improve prognosis as Brugada phenocopy is potentially reversible.