Coronary vasospasm caused by intravenous infusion of dexmedetomidine: Unrecognized pitfall of catheter ablation procedures of atrial fibrillation.

Coronary vasospasm is an emerging potentially lethal complication of catheter ablation for atrial fibrillation (AF), however, its mechanism in this setting has not been well elucidated. A 55-year-old man with symptomatic paroxysmal AF underwent pulmonary vein isolation under sedation with propofol. The procedure was completed without any complications. Fifteen months later, a repeated session was performed because of AF recurrence. Initially, a high-dose infusion of dexmedetomidine instead of propofol was administered to introduce sedation. Then, an ST-segment elevation developed in the inferior leads and the diagnosis of coronary vasospasm was made by urgent coronary angiography. A comparison of the procedural details between the first and second sessions identified dexmedetomidine, an α-2 adrenergic agonist with a short distribution half-life, as a potential cause of coronary vasospasm seen only in the second session in the same individual. Since it has been shown that α-2 adrenoreceptor-mediated vasoconstriction can involve the coronary circulation, it is thus possible that a stimulation of α-2 adrenergic receptors induced by dexmedetomidine caused a coronary vasospasm. The present case provides new insights into dexmedetomidine-induced vasospasm. Physicians should be aware of this potentially lethal side effect of dexmedetomidine which is increasingly used in the current AF ablation practice. <