Cardiac arrest associated with standard-dose carvedilol in combination with amiodarone: a case report

Patients with cardiac and metabolic comorbidities often undergo procedural intervention as well as pharmacological management. Medication adjustment is made in anticipation of and/or as a response to procedures. We present a case where failure to track and verify pre- versus post-procedural doses of a commonly prescribed medication led to substantial morbidity. This report emphasizes the need for vigilance even when using medications generally considered safe and for enhanced information sharing across different electronic medical record systems. A 61-year-old Hispanic man with hypertension, type 2 diabetes mellitus, and recent direct current cardioversion (DCCV) for new-onset atrial fibrillation was readmitted to the hospital for dyspnea. He had been recently discharged from the hospital for atrial fibrillation after being cardioverted to normal sinus rhythm. He was maintained, however, on carvedilol 25 mg twice daily—the same dose prescribed to him prior to DCCV—resulting in bradycardia, relative hypotension, acute kidney and liver injury. A few months later, at an elective admission at another hospital, he underwent ablation for refractory atrial fibrillation and was inappropriately restarted on the previous carvedilol dose; subsequently he had bradycardia and two Pulseless electrical activity (PEA) arrests. This case highlights that intolerance to Atrioventricular (AV)-nodal blockade and Bradycardia, Renal failure, AV nodal blockade, Shock, and Hyperkalemia (BRASH) physiology can occur at standard dosing, particularly with drug interactions and hemodynamic vulnerability. It underscores the importance of rigorous medication reconciliation, anticipatory de-escalation of rate-controlling agents after rhythm-control procedures, and improved cross-system access to prior adverse drug events. In the long term, individualized precision medicine may reduce adverse reactions to widely used medications at commonly prescribed doses.