1. Department of Cardiovascular Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan Central Hospital, Jinan, Shandong 250000, P.R. China
2. Dalian Medical University, Dalian, Liaoning 116000, P.R. China
3. Department of Cardiovascular Medicine, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China