Fig. 1

The ECGs of our case on the day of admission and on the morning of the day of cardiac tumor resection both demonstrated junctional escape-sinus capture bigeminy (A and B). After one week of pharmacological intervention following the temporary transvenous pacemaker implantation, the patient's ECG (C) showed the absence of P waves in all leads and the appearance of rapid and regular sawtooth-shaped F waves (250–350 bpm), predominantly with a 2:1 atrioventricular conduction ratio and occasional irregular f waves (350–450 bpm). The patient's ECG (D) after the implantation of a permanent pacemaker showed pacemaker-induced rhythm