Figure legends
Figure 1. (A) P-wave morphology of atrial premature contraction
(APC) in a 12-lead electrogardiogram. (B) The activation map of the APCs
demonstrated a focal pattern originating from the posteromedial inferior
vena cava (IVC) ostium. The earliest activation site was located 6.2 mm
below the IVC ostium, and (C) a local signal with a fragmented and low
amplitude (0.05 mV) was recorded. CS, coronary sinus; IVC, inferior vena
cava; SVC, superior vena cava.