Acute myocardial infarction following radiofrequency catheter ablation in a child: a case report on the mechanism of coronary artery occlusion assessed by cardiovascular imaging.

BACKGROUND: Radiofrequency ablation is a common treatment for atrioventricular nodal re-entrant tachycardia, even in paediatric patients weighing ≥15 kg, where outcomes are similar to those in adults. However, reports of acute coronary artery occlusion after radiofrequency ablation for atrioventricular nodal re-entrant tachycardia are rare.

CASE SUMMARY: An 11-year-old girl with symptomatic atrioventricular nodal re-entrant tachycardia refractory to drug treatment underwent radiofrequency ablation. During the procedure, ST elevation was observed, and coronary angiography revealed occlusion of the right coronary artery at the segment 4 atrioventricular branch. Intravascular ultrasonography showed a narrowed lumen and an abnormal area of low echogenicity in the adjacent myocardium. After dilation with a 1.5 mm diameter balloon, blood flow was successfully restored. Follow-up coronary computed tomography angiography revealed residual stenosis in the right coronary artery at the segment 4 atrioventricular branch; however, blood flow to the distal occlusion was preserved. The patient was discharged without further complications.

DISCUSSION: To the best of our knowledge, this is the first report of coronary artery occlusion following radiofrequency ablation for atrioventricular nodal re-entrant tachycardia, evaluated using intravascular ultrasonography and coronary computed tomography angiography. Based on the imaging findings, direct thermal injury was considered the cause of occlusion.