In vivo visualization of the blood separation in the left ventricular chamber: a case of fulminant myocarditis requiring venoarterial extracorporeal membrane oxygenation

Excerpt

A 33-year-old woman was admitted with a clinical diagnosis of fulminant myocarditis. Echocardiography showed severe left ventricular (LV) hypokinesis, with diffuse wall motion abnormalities (ejection fraction, 20 %) (Fig. 1a). The patient developed rapidly worsening hemodynamics with hypoxia and an unmeasurable blood pressure; we therefore performed venoarterial extracorporeal membrane oxygenation (VA-ECMO), intubation with use of an intra-aortic balloon pump, and intravenous heparin infusion. The VA-ECMO flow was maintained at 3–4 L/min. The activated partial thromboplastin time was 98 s. Only 3 h after initiating VA-ECMO, echocardiography revealed aortic valve closure and sedimentation in the LV chamber. The sedimentation was clearly separated into supernatant and sludge components as a result of the difference in specific gravity, mimicking blood separation (Fig. 1b, c, Video 1). Despite the aortic valve closure, blood movement through the mitral valve was still observed (Fig. 1d); this might have prevented sludge formation in the LV inflow tract. Despite thrombectomy and implantation of an LV assist device, the patient developed fatal multiorgan failure. Pathology autopsy confirmed myocarditis (Fig. 1e). In patients with severe myocardial dysfunction, VA-ECMO circulation in a nonphysiological direction rarely induces aortic valve closure, leading to blood stagnation and rapid sludge formation in the LV chamber.

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