Objective:To investigate the efficacy of trimetazidine in the treatment of atrial arrhythmias in patients with ischemic cardiomyopathy and heart failure and analyze the effect of trimetazidine on cardiac function and atrial arrhythmias.Methods:A total of 79 patients with ischemic cardiomyopathy and heart failure who received treatment at the Second Hospital of Jiaxing from December 2018 to June 2020 were included in this study. These patients were randomly divided into an observation group ( n = 41) and a control group ( n = 38). Patients in the control group received conventional drugs, while those in the observation group received trimetazidine sustained-release tablets twice daily, each time taking 35 mg in addition to conventional drugs. The treatment lasted for 24 weeks. Before and after treatment, cardiac function indicators (left ventricular ejection fraction, B-type brain natriuretic peptide, 6-minute walking distance), cardiac color Doppler ultrasound indicators [ratio of early to late peak filling rate (E/A ratio)], left ventricular fractional shortening), electrocardiogram parameters (maximum P-wave duration, minimum P-wave duration, and P-wave dispersion), dynamic electrocardiogram parameters [number of single atrial premature beats, total number and duration of paroxysmal atrial tachycardia episodes, total number and duration of paroxysmal atrial flutter/fibrillation attacks, standard deviation of RR intervals, root mean square of successive differences between normal heartbeats, proportion of successive RR intervals that differ by more than 50 ms divided by the total number of NN intervals (PNN50), standard deviation of average NN intervals, high frequency and low frequency], as well as changes in high sensitivity C-reactive protein were analyzed in each group. Results:After treatment, left ventricular ejection fraction, B-type brain natriuretic peptide, 6-minute walking distance, maximum P-wave duration, P-wave dispersion, total number of atrial flutter/atrial fibrillation attacks, and duration of atrial flutter/atrial fibrillation in the observation group were (51.05 ± 7.68)%, (1 615.59 ± 1 129.78) ng/L, (350.02 ± 62.99) m, (99.73 ± 11.60) ms, (22.44 ± 12.03) ms, (0.22 ± 0.61), and (4.59 ± 12.30) minutes, respectively, which were significantly superior to (46.82 ± 7.34)%, (2 267.47 ± 1 539.03) ng/L, (294.16 ± 58.20) m, (111.71 ± 10.00) ms, (36.77 ± 15.07) ms, (0.76 ± 1.13), (15.66 ± 22.30) minutes in the control group, t = -2.95, 2.16, -4.08, 4.89, 4.68, 2.69, 2.76, all P < 0.01). Conclusion:Trimetazidine can effectively reduce atrial arrhythmias and improve the prognosis of patients with ischemic cardiomyopathy and heart failure, which warrants clinical promotion.