Seizure and regadenoson: An underestimated concern

For 15 years, regadenoson, a selective adenosine 2A (A2A) receptor agonist, has been largely used as a pharmacologic stress agent in myocardial perfusion studies. It acts by increasing coronary blood flow. It has been shown to be non-inferior to adenosine for the detection of reversible myocardial ischemia. Regadenoson has several advantages, including less serious adverse effects, better tolerance and easier practical administration. However, specific adverse effects on the central nervous system, although rarely reported, can provocoke seizure through A2A receptor activation. We report here a case of regadenoson-associated-seizure and review the relevant literature. A 73-year-old male with a past medical history of hypertension, atrial fibrillation, stroke, hemodialysis and type 2 diabetes was referred for evaluation of hypokinesia of the apical segments. He had an unique episode of epilepsia in 2008. Less than one minute after regadenoson injection, he had a partial tonic-clonic seizure of the right upper and lower limbs, which lasted for 30 seconds and resolved spontaneously. This case report is a reminder that this under-diagnosed adverse effect must be taken into consideration when using regadenoson for cardiac stress testing.