RESUMEN
Objective To explore the effects of heart rate changes after holding breath and time for recovering stable heart rate on the quality of coronary CTA.Methods Totally 700 patients undergoing coronary CTA examination in some hospital were enrolled into the study,whose data on initial heart rate at rest condition,maximal heart rate during breath holding,stable heart rate after breath holding as well as the time consumed for recovering stable heart rate were collected and analyzed.Results A heart rate trendgram was drawn to find out the rules for heart rate changes and time for recovering stable heart rate,so that proper retrospective or prospective scanning scheme could be determined.Conclusion Mastering the rules in heart rate changes and time for recovering stable heart rate contributes to guiding coronary CTA.