[BRASH syndrome: the vicious cycle of bradycardia, hyperkalemia and renal failure].

BRASH syndrome is an acronym for Bradycardia, Renal failure, AV blockade, Shock, and Hyperkalemia. It arises from the synergy between AV nodal blocking medications (such as beta-blockers or calcium antagonists), renal failure, and hyperkalemia, leading to bradycardia and renal hypoperfusion. This exacerbates the decline in renal function and hyperkalemia, increasing the effect of AV-node blocking medication and creating a vicious cycle with the risk of multi-organ failure. Patients often improve with basic supportive therapy, such as discontinuing AV nodal blockers, correcting hyperkalemia, and rehydration. We present a case that highlights the importance of early recognition of this often-overlooked syndrome in patients with combined cardiovascular and renal comorbidities.