After surgery, patients may sometimes feel discomfort or mild pain in the precordial region, which usually disappears in about 1 month. There are small hematomas, purple spots, and pressure pain at the puncture site. It is important to ask the doctor to examine it carefully to exclude arteriovenous fistula or aneurysm; if there is no arteriovenous fistula or aneurysm, it will usually disappear gradually on its own in about 2 to 4 weeks. Sometimes there is a hard node at the puncture site, which usually disappears after 3 to 6 months. Sometimes patients have occasional premature beats, which may be related to the mechanical or electrical stimulation of the catheter during the procedure. If preoperative symptoms occur, do not be overly nervous. An electrocardiogram should be done as soon as there are symptoms to determine if there is a recurrence or another arrhythmia.