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
To set up rat myocardial infarction model and to investigate significance of fragmented QRS wave in rat myocardial infarction model.40 rats were divided into sham-operated group and myocardial infarction group, these two sets of rats received surgeries under the same conditions.Myocardial infarction models were induced by opening chest and anterior descending branch of coronary artery deligation for rats.Rats in sham-operated group were only threaded without deligation.Recorded the electrocardiogram(ECG) during 10, 60 min and 4 weeks after the deligation(or threading) and analyzed the change rules of the fragmented QRS waves and Q waves.Tissue samples from myocardial infarction area were collected for HE staining 4 weeks after the surgery.The frequency of fragmented QRS wave in myocardial infarction group was significantly increased during 10, 60 min and at 4 weeks after the operation compared with sham-operated group(P<0.01).Myocardial cells of some models in myocardial infarction group arranged in disorder and showed vacuolation according to results of HE staining.By setting up rat myocardial infarction model, we can draw a conclusion that fragmented QRS wave can be used as a new indicator to diagnose acute myocardial infarction and old myocardial infarction predict the severity of the disease.