Purposes: Evaluate following up and taking care of patients periproceduaral the electrophysiologystudy and catheter radiofrequency ablation at Thong Nhat hospital from March to June 2015. Method: Retrospective study of 160 patients admitted to Interventional Cardiology and Emergency department, Thong Nhat hospital from March to June 2015 for doing electrophysiology study and catheter radiofrequency ablation. Result: The average of age is around 47.01 years old, with 5pts (16%) younger than 18 years old and 120 pts (75%) older than 60 years old.