Background

In sepsis-induced cardiogenic shock, venoarterial extracorporeal membrane oxygenation (VA-ECMO) can improve survival. Simultaneous acute respiratory distress syndrome (ARDS) increases the risk of differential hypoxia (Harlequin syndrome). Due to desaturated blood ejected by the heart, the head becomes blue, whereas the lower body remains oxygenated by VA-ECMO. We report on an unusual cardiac manifestation, leading to electrical storm.
Case summary

We present the clinical case of a 55-year-old man. During a minor viral pneumonia, superinfection led to severe ARDS and sepsis-induced refractory cardiogenic shock. Venoarterial extracorporeal membrane oxygenation support was initiated. In progressive respiratory failure, an electrocardiogram (ECG) revealed the onset of ST-segment elevations mirroring hypoxic coronary perfusion. As the mixing zone of blood from the heart and the VA-ECMO was in the ascending aorta, hypoxia was limited to the heart. Ventricular arrhythmias recurred, until ventricular fibrillation remained refractory to defibrillation. A second return cannula was inserted into the jugular vein, and veno-arteriovenous ECMO (V-AV-ECMO) was established. After the venous return was added to the circuit, ventricular fibrillation was defibrillated and sinus rhythm remained stable. Within an hour, ST-elevations receded. Systolic function recovered to normal within 26 days.
Discussion

In severe sepsis-related cardiogenic shock, cardiac output is likely to recover. Venoarterial extracorporeal membrane oxygenation is a potential bridge to recovery. Apart from textbook knowledge, Harlequin syndrome can exclusively cause coronary ischaemia, leading to ST-segment elevations and electrical storm. ECGs reveal ST-elevations for early detection. Isolated cardiac Harlequin syndrome can be overlooked or misinterpreted as result of coronary artery disease, but needs immediate therapy to save the patient’s life (e.g. V-AV-ECMO).