Dengue myopericarditis A case report.

Abstract

Introduction: Cardiac tamponade is a life-threatening emergency requiring prompt intervention. Among its various causes, viral infections are most likely to progress to tamponade. Dengue is an acute febrile viral illness affecting an estimated 390 million people annually worldwide. It can present asymptomatically or subclinically or with severe manifestations. Cardiac involvement, including myocarditis, pericarditis, and arrhythmias, has been associated with dengue. Myocarditis is a common complication of severe dengue, and its frequency directly correlates with disease severity. Defined as inflammation of the heart muscle, myocarditis is a significant cause of acute heart failure, sudden death, and dilated cardiomyopathy. An endomyocardial biopsy can establish the etiological agent.

Case Report: A 39-year-old man with no significant medical history presented with dyspnea, hypotension, tachycardia, and precordial pain associated with a four-day history of myalgia, arthralgia, and fever. On admission, he was febrile with an exanthem. Laboratory tests revealed leukopenia and mild thrombocytopenia, which improved upon discharge. Initial echocardiography showed a left ventricular ejection fraction of 50% with global hypokinesia and severe pericardial effusion measuring approximately 800 ml, with signs of tamponade. Electrocardiography demonstrated low voltage complexes in the limb leads with electrical alternans. Dengue and chikungunya serology was positive for dengue IgM and IgG. Subsequent cardiac magnetic resonance imaging (CMR) revealed a significant reduction in left ventricular ejection fraction to 36% with diffuse motility disorders, suggesting biventricular involvement in the non-edematous phase of myocarditis.

Conclusion: The case was discussed by a heart team, and a diagnosis of severe dengue myocarditis was established. Timely intervention saved the patient's life, and he is currently in New York Heart Association (NYHA) functional class II/III with a mildly reduced ejection fraction, receiving optimal heart failure therapy. The low cardiac output suggests that cardiac involvement was present from the onset of dengue infection. Therefore, myocarditis was the presenting manifestation of the disease despite being considered unusual.