Frequent palpitations during chemotherapy

A 66-year-old female patient was diagnosed with breast cancer. A venous access port for chemotherapy was implanted. A month later she started feeling recurrent rapid palpitations. Upper left panel shows the onset of a narrow QRS complex tachycardia triggered by an atrial ectopy, with different P-wave configurations (ectopy vs. tachycardia) (arrows). A concealed left free wall accessory pathway was diagnosed and ablated. Lower left panel shows entrainment during right ventricular (RV) pacing with V-A-V response (local VA changed only 10 ms), and right lower panel shows V-A conduction during RV pacing during radiofrequency (RF) current deliver: RF is the electrogram from the earliest atrial activation site, showing retrograde A-V nodal Wenckebach after ablation of the accessory pathway. Fluoroscopy (right upper panel) shows the ablation site, and arrowheads point to the catheter tip, triggering ectopies and atrioventricular re-entrant tachycardia by mechanical stimulation (Supplementary material online, Video S1). After ablation, tachycardia no longer occurred. Ectopy disappeared after catheter repositioning. Supplementary material is available at Europace online.