title: [Relationship between hematocrit (Hct) and cardiac systolic time intervals (STI) in residents at 4300 m altitude].
abstract: In order to study the relationship between Hct and cardiac systolic time intervals (STI) in residents at high altitude, STI and cardiac function were determined by electrical impedance and carotid arteriogram in 113 subjects with different Hct at an altitude of 4300 m. There was a negative correlation between Hct and SV or EF (r = -0.841 and -0.628), respectively (P < 0.001). With increase of Hct there were prolonged pre-ejection period (PEP), shortened left ventricular ejection time (LVET), and increased PEP/LVET. SV, CO were lower in high altitude polycythemia (HAPC) than in the control (P < 0.05). It demonstrated that there is a close relationship between STI and Hct, and excessive polycythemia is one of the important factors that cause decrease of cardiac function decreasing in high altitude residents.
authors.affiliation: Qinghai Research Institute of Altitude Medical Science, Xining.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Wu
authors.forename: Q
authors.initials: Q
authors.lastname: Chen
authors.forename: C
authors.initials: C
authors.lastname: Wei
authors.forename: G
authors.initials: G
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D001274:Atmospheric Pressure; D002320:Cardiovascular Physiological Phenomena; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D017097:Electric Impedance; D004912:Erythrocytes; D006400:Hematocrit; D006801:Humans; D011086:Polycythemia / Q000503:physiopathology; D011859:Radiography; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology*; D016277:Ventricular Function, Left