Bradycardia, Renal Failure, Atrioventricular Nodal Blockade, Shock, and Hyperkalemia Syndrome as a Clinical Profile Leading to the Diagnosis of Transthyretin Amyloidosis: A Report of Two Cases.

We describe two cases in which the onset of bradycardia, renal failure, atrioventricular (AV) nodal blockade, shock, and hyperkalemia (BRASH) syndrome led to the diagnosis of transthyretin cardiac amyloidosis. In Case 1, BRASH syndrome developed shortly after a therapeutic dose of AV nodal blockers was prescribed for new-onset atrial flutter. BRASH syndrome improved with intravenous dopamine infusion and temporary cardiac pacing. In Case 2, BRASH syndrome developed immediately after bronchopneumonia followed by worsening heart failure, despite no change in medications such as AV nodal blockers. Intravenous injection of calcium dramatically improved BRASH syndrome.