Correlation Analysis Of Cardiac Function Parameters Between Heart Rate Recovery After Exercise Stress Test And Myocardial Perfusion Imaging Under Exercise Stress

Objective:Cardiac function parameters calculated after myocardial perfusion imaging under exercise stress are of great significance for evaluating myocardial function and activity.These parameters include end-diastolic volume(EDV),end-systolic volume(ESV),peak ejection fraction(PER)and peak filling rate(PFR),etc.Heart rate recovery after exercise was an independent predictor of cardiovascular disease and mortality.The aim of this study was to investigate the relationship between heart rate recovery(HRR)after exercise and cardiac function parameters on myocardial perfusion imaging during exercise stress,and analyze whether easily accessible post-exercise HRR could be used to predict cardiac function parameters.Methods:Retrospective analysis was performed on 232 patients(117 males and 115 females,aged(55.2±10.2)years),who underwent myocardial perfusion imaging under exercise stress in our hospital from May 2014 to May 2019.The exercise stress test scheme was the BRUCE scheme,in which the heart rate changes were monitored during exercise.the maximum heart rate during exercise and the heart rate 1min after exercise were recorded,and the heart rate during myocardial perfusion imaging of the patients was obtained.Myocardial perfusion imaging was performed 30-60 minutes after the exercise,and left ventricular systolic and diastolic function was analyzed by Quantitative Gated SPECT(QGS),and EF,EDV,ESV,PER and PFR parameters were obtained to evaluate left ventricular function.Results:1.Heart rate recovery at imaging time(202 cases)were divided into group 1(HRR≥59.5)and group 2(HRR<59.5)by the median(59.5 bpm)of HRR.There were no significant differences between the two groups in gender,resting heart rate,time from exercise to imaging,-PER,PFR and EF(P > 0.05)but significant differences in clinical diagnosis and history of hypertension(P=0.003,P < 0.001).Age and EF of group2 were higher than those of group1(age:58.5±9.4 vs 54.7±8.0;EF:58.0(52.0,63.0)vs 55.0(50.0,61.0)),meanwhile,EDV and ESV were lower(EDV:60.0(50.0,78.0)vs 69.0(56.0,84.6);ESV:25.0(17.5,36.0)vs 30.0(22.0,41.5)).2.Heart rate recovery at 1min after exercise(85 cases)were divided into group 1(HRR≥34)and group 2(HRR<34)based on the median(34 bpm)of HRR.There were no significant differences in sex,resting heart rate,EDV,ESV,EF,-PER and PFR between the two groups(P > 0.05).Only significant differences were found in age,clinical diagnosis and history of hypertension(P=0.024,0.024,0.023).3.In group 1 at imaging time,there was a certain correlation between HRR and EDV,ESV,EF,-PER,PFR(r = 0.25,0.33,-0.29,-0.43,-0.41;P < 0.05),But in other three groups,there was no correlation between HRR and the five parameters(P> 0.05).Conclusion:1.Age,disease type and history of hypertension were significantly related to HRR after exercise,and the age of HRR < median array was significantly higher than that of HRR≥ median array.2.There was a significant relationship between HRR and EDV,ESV and EF during imaging,but there was no significant relationship between HRR and EDV,ESV and EF1 min after exercise,which might be related to the fact that the sympathetic nerve still maintained some excitability and the parasympathetic nerve did not activate quickly after exercise.3.When HRR≥ median during imaging,HRR was positively correlated with EDV and ESV,and negatively correlated with EF,PER and PFR.However,there is no correlation between the HRR < median array during imaging and the HRR 1min after motion.This may be because 1min after exercise is associated with lower parasympathetic activity when HRR is reduced.4.HRR can be used as a weak predictor of cardiac function parameters when HRR≥median during imaging.