Fulminant Influenza A Myocarditis Complicated by Transient Ventricular Wall Thickening and Cardiac Tamponade

Abstract

Myocarditis is an infrequent complication of influenza infection that is most often diagnosed clinically in the setting of confirmed influenza infection and elevated cardiac enzymes. Pericarditis can also occur in cases of influenza myocarditis and may require pericardiocentesis for tamponade. Patients with fulminant myocarditis have cardiogenic shock; however, echocardiographic findings may be subtle, showing a preserved ejection fraction and diffuse left ventricular wall thickening (compared to baseline) due to inflammatory edema. Recognizing these echocardiographic findings in the appropriate clinical setting facilitates the early recognition of fulminant myocarditis. Therefore, we report a case of fulminant influenza A myocarditis in healthy 37-year-old women complicated by transient left ventricular wall thickening and tamponade, highlighting the importance of early diagnosis and supportive management for a successful outcome.

Keywords: cardiac tamponade; fulminant myocarditis; influenza A; myocardial edema.

Figure 1

TTE (parasternal long-axis view) showing an increasing pericardial effusion measuring 1.33 cm (marked by two white stars).

Figure 2

Parasternal short-axis view of TTE: (A) during the acute illness revealing 15 mm LV wall thickness; (B) 1-month follow-up demonstrating 10 mm LV wall thickness.

Figure 3

Gadolinium enhanced cardiac MRI pointing to the patchy sub-epicardial delayed enhancement of the basal lateral/inferolateral wall (red arrow).