In the non-SR group, there was one cardiac death in the patient with both TTN and TMEM43 mutations due to refractory HF and electrical storm following a severe COVID infection, despite having the clinical and paraclinical criteria of a super-responder (nonischemic, younger age, typical LBBB pattern, wider QRS, and LV lead in the posterolateral position). The gene discussed is TTN; the disease is hydrops fetalis.