Affiliation: | (1) Department of Cardiology, Akita City General Hospital, 4-30 Kawamotomatsuoka, Akita 010-0933, Japan;(2) Department of Clinical Physiology, Akita City General Hospital, Akita, Japan;(3) Kibira Medical Clinic, Akita, Japan;(4) Center of Diagnostic Ultrasound, Red Cross Hospital, Akita, Japan |