Study On Coronary Artery Diameter And Myocardial Perfusion Of High Altitude Polycythemia With Revolution CT

Objective: Revolution CT one-stop coronary CT angiography and CT perfusion imaging was used to compare the difference of coronary diameter and myocardial perfusion between high altitude patients with high altitude polycythemia(HAPC)and healthy controls at the same altitude,and to explore whether the changes of coronary diameter and Myocardial perfusion occur in HAPC patients at high altitude.Methods: 31 HAPC patients of Han nationality and 31 healthy controls of Han nationality at the same altitude were collected from September 2017 to December 2019.Using GE 256 revolution CT of the United States to carry out a one-stop examination for all examiner.Before the examination,the height and weight were measured.The total dose of contrast agent and injection speed were calculated automatically by the computer according to the formula.The original scanning image was obtained and disassembled into 0.625 mm layer thickness and transmitted to aw4.6 post-processing workstation.The diameter of left main coronary artery(LM),right coronary artery(RCA),left circumflex coronary artery(LCX)and left anterior descending(LAD)were measured.According to the 17 segment standard method recommended by the American Heart Association(AHA)(the 17 th segment was not included in the analysis).The BV,BF,MTT,TTP and PS perfusion parameters of 16 segments of myocardium were measured by hand sketching.Data were collected and statistically analyzed to compare the difference of coronary diameter and myocardial perfusion between HAPC patients and health examinees at the same altitude.Results: 1.Patients with HAPC had greater red blood cell,hemoglobin,and hematocrit than healthy controls,and platelets were smaller than the control group,with statistically differences(P <0.05).2.The diameters of LM,LAD,LCX,and RCA of HAPC patients were larger than those of healthy controls,and all had statistical differences(P <0.05).3.The BF value of HAPC patients was lower than that of healthy controls,and the values of BV,MTT,TTP,and PS were higher than those of healthy controls,all of which had statistical differences(P <0.05).Conclusion: In order to adapt to the high altitude hypoxic environment,patients with high altitude erythrocytosis have changes in coronary diameter and myocardial perfusion,that was,compensatory thickening of coronary diameter and reduced myocardial blood flow,the heart was in a state of low perfusion,and there may have a risk of myocardial ischemia.