ABSTRACT
Objective:To explore the relationship between fragmented QRS complex and heart rate variability (HRV) and ventricular arrhythmia in patients with old myocardial infarction.Methods:From August 2018 to October 2019, 200 patients with old myocardial infarction were first treated in the Department of cardiac function examination of the First Affiliated Hospital of Hebei North University. The patients were divided into 99 cases of old myocardial infarction with fragmented QRS wave group and 101 cases of old myocardial infarction without fragmented QRS wave group according to the case bank data and conventional 12 lead ECG diagnosis in our hospital for the first time. Then, the 24-h ambulatory ECG reexamined within 1 year after discharge was retrospectively analyzed. The incidence of ventricular arrhythmia was compared between the two groups by χ 2 test. The difference of heart rate variability between the two groups was compared by rank sum test. Multiple logistic regression was used to analyze the value of different indexes of heart rate variability in the evaluation of fragmented QRS complex in old myocardial infarction. Drawing the receiver operating characteristic (ROC), and the area under the curve (AUC) was used to analyze the diagnostic accuracy of different indexes of heart rate variability in the broken QRS complex of old myocardial infarction. Results:According to the Lown classification of ventricular premature contraction, the number of positive ventricular arrhythmias in patients with Grade Ⅰ of ventricular premature contraction and Grade Ⅲ-Ⅴ of ventricular premature contraction in the old myocardial infarction fragmented QRS group was higher than that in the old myocardial infarction non fragmented QRS group (Grade Ⅰ of ventricular premature contraction: 54.5% (54/99)and 39.6%(40/101); χ 2=4.484, P<0.05;Grade Ⅲ-Ⅴ of ventricular premature contraction: 34.3% (34/99) and 9.9%(10/101); χ 2=17.406, P<0.05)). Ventricular premature contraction Grade 0 old myocardial infarction fragmented QRS group was lower than old myocardial infarction non fragmented QRS group (8.1% (8/99) and 48.5% (49/101); χ 2=37.995, P<0.05). The total number of positive cases of ventricular arrhythmia in the old myocardial infarction group with fragmented QRS wave was higher than that in the old myocardial infarction group without fragmented QRS wave (91.9% (91/99) and 51.5%(52/101); χ 2=57.146, P<0.05)). There was no significant difference in the number of positive ventricular arrhythmias between the old myocardial infarction fragmentation QRS group and the old myocardial infarction non fragmentation QRS group ( P>0.05). The standard deviation of NN intervals (SDNN) and the standard deviation of average NN intervals (SDANN) of HRV time domain indexes in the old myocardial infarction fragmented QRS group were higher than those in the old myocardial infarction non fragmented QRS Group (SDNN:143.00(122.00,166.00) vs. 110.00(95.00,130.50), Z=5.780, P<0.05; SDANN:112.00(100.00,136.00) vs. 96.00(76.00,118.50), Z=4.013, P<0.05). Multiple Logistics regression analysis results of HRV domain shows that HRV time domain SDNN and SDANN have diagnositic value in diagnosis fQRS after OMI(SDNN: OR=0.949, 95% CI:0.922-0.977, P<0.001; SDANN: OR=1.036, 95% CI:1.005-1.068, P=0.022). Area under ROC curve of HRV time domain SDNN and SDANN have particular diagnositic accuracy in diagnosis fQRS after OMI(SDNN: AUC 0.737, 95% CI 0.666-0.807, Sensitivity 0.818, Specificity 0.634; SDANN: AUC 0.664, 95% CI 0.587-0.741, Sensitivity 0.737, Specificity 0.673. 0.5<AUC<1). Conclusion:Fragmented QRS complex was positively correlated with the incidence and severity of ventricular arrhythmia in patients with old myocardial infarction, and positively correlated with time-domain indexes SDNN and SDANN of heart rate variability in patients with old myocardial infarction.
ABSTRACT
Pharmaceutical cocrystals are a promising technology that can be used to improve the solubility of poor aqueous compounds. The objective of this study was to systematically investigate the solubility of myricetin (MYR) cocrystals, including their kinetic solubility, thermodynamic solubility, and intrinsic dissolution rate (IDR). The effects of pH, surfactant, ion concentration, and coformers on the cocrystal solubility were evaluated. Furthermore, single crystal structures of MYR, myricetin-isonicotinamide (MYR-INM) and myricetin-caffeine (MYR-CAF) cocrystals were analyzed to discuss the possible reasons for the enhancement of cocrystal solubility from the perspective of the spatial structure. The results indicated that the kinetic solubility of MYR cocrystals was modulated by pH and cocrystal coformer (CCF) ionization in buffer solution, while it primarily depended on the CCF solubility in pure water. In addition, the solubility of MYR cocrystals was increased in a concentration dependent fashion by the surfactant or ion concentration. The thermodynamic solubility of MYR-INM (1:3) cocrystals decreased with the increases of the pH value of the dissolution media. The IDR of MYR cocrystals was faster than that of MYR in the same medium and extremely fast in pH 4.5 buffer. The improved solubility of MYR cocrystals was probably related to the alternate arrangements of MYR and INM/CAF molecules and increased intermolecular distance. The present study provides some references to investigate the solubility behavior of pharmaceutical cocrystals.