BRASH Syndrome with Hyperkalemia: An Under-Recognized Clinical Condition.

BRASH syndrome is characterized by bradycardia, renal failure, use of an atrioventricular nodal blocker (AVNB), shock, and hyperkalemia. These symptoms represent an ongoing vicious cycle in a patient with a low glomerular filtration rate taking an AVNB. Decreased clearance of the medication and hyperkalemia associated with renal failure synergize to cause bradycardia and hypoperfusion. This reaction causes renal function to worsen, thereby perpetuating the cycle of BRASH syndrome.