Objective To explore the perioperative trend of heart rate variability(HRV)in patients undergoing aortic valve replacement(AVR)under cardiopulmonary bypass and investigate the influence of age and/or postoperative atrial fibrillation(POAF)on this trend.Methods Baseline and clinical data of 134 patients undergoing AVR due to aortic valve disease in Department of Car-diovascular Surgery of Northern Theater General Hospital of PLA from January 2021 to January 2023 were collected and retrospectively studied.According to the age and/or POAF,they were divided into group A(aged＜60 years,no POAF,49 cases),group B(aged＜60 years,complicated with POAF,21 cases),group C(aged≥60 years,no POAF,30 cases)and group D(aged≥60 years,with POAF,34 cases).The dynamic electrocardiogram indicators were collected in 7 d be-fore and 7 d after operation.The changes in perioperative HRV were also observed.Results After operation,the standard deviation of sinus heart beat RR intervals,average of the standard devia-tions of NN intervals for each 5 min segment of a 24 h HRV recording(SDNNidx),root mean square of successive RR interval differences,and percentage of successive RR intervals that differ by more than 50 ms were significantly lower than those in 7 d before operation[61.172±17.449 ms vs 804.567±230.518 ms,20.284±9.432 ms vs 42.933±12.876 ms,1.307±0.196 ms vs 1.412±0.148 ms,3.00(1.30,7.23)ms vs 5.30(3.00,10.40)ms,P＜0.01].The group D had obvi-ously lower SDNNidx than the group A in 7 d after surgery(42.568±14.749 ms vs 46.467±11.754 ms,P＜0.05).Conclusion Autonomic dysfunction is observed in the early stage after AVR.For the patients aged≥60 years with POAF,the HRV indicators are significantly decreased,the dys-function of the vagus nerve is aggravated,and the disorder is exacerbated because of their syner-gistic effect.

Objective To explore the perioperative trend of heart rate variability(HRV)in patients undergoing aortic valve replacement(AVR)under cardiopulmonary bypass and investigate the influence of age and/or postoperative atrial fibrillation(POAF)on this trend.Methods Baseline and clinical data of 134 patients undergoing AVR due to aortic valve disease in Department of Car-diovascular Surgery of Northern Theater General Hospital of PLA from January 2021 to January 2023 were collected and retrospectively studied.According to the age and/or POAF,they were divided into group A(aged＜60 years,no POAF,49 cases),group B(aged＜60 years,complicated with POAF,21 cases),group C(aged≥60 years,no POAF,30 cases)and group D(aged≥60 years,with POAF,34 cases).The dynamic electrocardiogram indicators were collected in 7 d be-fore and 7 d after operation.The changes in perioperative HRV were also observed.Results After operation,the standard deviation of sinus heart beat RR intervals,average of the standard devia-tions of NN intervals for each 5 min segment of a 24 h HRV recording(SDNNidx),root mean square of successive RR interval differences,and percentage of successive RR intervals that differ by more than 50 ms were significantly lower than those in 7 d before operation[61.172±17.449 ms vs 804.567±230.518 ms,20.284±9.432 ms vs 42.933±12.876 ms,1.307±0.196 ms vs 1.412±0.148 ms,3.00(1.30,7.23)ms vs 5.30(3.00,10.40)ms,P＜0.01].The group D had obvi-ously lower SDNNidx than the group A in 7 d after surgery(42.568±14.749 ms vs 46.467±11.754 ms,P＜0.05).Conclusion Autonomic dysfunction is observed in the early stage after AVR.For the patients aged≥60 years with POAF,the HRV indicators are significantly decreased,the dys-function of the vagus nerve is aggravated,and the disorder is exacerbated because of their syner-gistic effect.

OBJECTIVE:To establish HPLC-quadrupole/electrostatic field orbitrap high resolution mass spectrometry for rapid determination of aconitine,mesaconitine,hypaconitine,benzoylaconitine,benzoylmesaconine and benzoylhypacoitine in rat plasma. METHODS:Internal standard lappaconitine was added into plasma sample,and methanol precipitated protein was used for pretreatment. HPLC-quadrupole/electrostatic field orbitrap high resolution mass spectrometry was adopted. HPLC condition was as follows as Sinochrom ODS-BP C18column,mobile phase consisted of acetonitrile-1% formic acid solution(50:50,V/V),the flow rate of 0.6 mL/min,sample size of 10 μL,column temperature of 25 ℃,automatic sampler temperature of 4 ℃. Mass spectrum scanning mode was full ion monitoring model,positive ion acquisition,mass charge ratios(m/z)of ion were 646.32(aconitine), 632.30(mesaconitine),616.31(hypaconitine),604.31(benzoylaconitine),590.29(benzoylmesaconine),574.30(benzoylhypacoitine), 585.31(internal standard). Six male Wistar rats were collected and given single dose of total alkaloid extract of Aconitum carmichaeli(4 mg/kg)intragastrically. Blood samples were collected before medication(0 h)and 0.5,0.75,1.25,1.5,2,4,6, 8,10,24 h after medication. Plasma concentration was determined and pharmacokinetic parameters were calculated by using PK-Solver V2.0 software. RESULTS:The linear range of 6 kinds of aconitum alkaloids in plasma were 0.1-10 μ g/L(r>0.992). The limit of quantitation was 0.1 μ g/L. Average recovery was higher than 75%,RSDs of intra-day and inter-day,matrix effects,stability test were all lower than 15%. The tmaxof 6 kinds of aconite alkaloids were about 1.2 h;t1/2were about 10 h;cmaxof monoestertype aconite alkaloids were higher than those of diester-type aconite alkaloids. CONCLUSIONS:Established HPLC-quadrupole/electrostatic field orbitrap high resolution mass spectrometry is accurate,sensitive,simple and rapid, and can be used for plasma concentration monitoring of 6 kinds of aconitum alkaloids.