Current Trends and Future Perspectives of Bradycardia, Renal Failure, Atrioventricular Nodal Blockade, Shock, and Hyperkalemia (BRASH) Syndrome: A Narrative Review

BRASH syndrome is defined as a clinical condition in which bradycardia, renal failure, atrioventricular (AV) nodal blockade, shock, and hyperkalemia interact to form a self-perpetuating negative spiral. Geriatric practitioners are increasingly likely to encounter elderly patients with this syndrome who are taking AV nodal blocking agents, such as calcium channel blockers (CCBs) or β-blockers. However, it remains unclear how the heart failure (HF) pandemic and coronavirus disease 2019 (COVID-19) have influenced the incidence, triggers, management, and clinical course of BRASH syndrome. Therefore, open-access databases were searched for publications from 1980 to 2025, identifying 41 eligible articles reporting a total of 54 patients with BRASH syndrome. The mean age of affected patients was 69.0 ± 15.1 years. Hypertension (HTN, 74%), chronic kidney disease (CKD, 61%), and diabetes (54%) were the most common comorbidities. More than half of the patients (52%) were prescribed angiotensin-suppressing agents (angiotensin-converting enzyme inhibitors (ACEi), angiotensin receptor blockers (ARB), or angiotensin receptor-neprilysin inhibitors (ARNI)) for HTN or HF. Two elderly patients were diagnosed with BRASH syndrome triggered by COVID-19. This literature review clarifies that BRASH syndrome commonly occurs in elderly patients with HTN or CKD and is often associated with everyday clinical events such as anorexia, vomiting, diarrhea, bleeding, and infection, including COVID-19. Our database search supports recognizing BRASH syndrome as an important clinical entity in geriatric emergency medicine. Geriatric practitioners should be aware of this condition to enable early diagnosis and appropriate management in the modern HF and post-COVID-19 era.