Objective To quantitatively evaluate the changes of right ventricular function and myocardial strain in patients with coronary artery chronic total occlusion (CTO) during long-term follow-up after treatment by cardiac magnetic resonance (CMR).Methods A total of 13 patients who were diagnosed as coronary artery CTO in The First Affiliated Hospital of Dalian Medical University from Jan. 2015 to Dec. 2019 and completed CMR scanning before and after treatment were enrolled. The left and right ventricular structural and functional parameters as well as right ventricular myocardial strain parameters were measured by CVI42 5.10 software, and the differences of these parameters were analyzed before and after treatment.Results The interval between 2 CMR examinations was 259 to 1 168 d in the patients, with an average of (500.08±228.34) d. In terms of left ventricular parameters, left ventricular end-diastolic volume and left ventricular end-systolic volume were significantly increased after treatment, while left ventricular mass was significantly decreased (148.35 [141.70, 181.66] mL vs 140.08 [116.42, 170.90] mL, 77.78 [52.41, 100.24] mL vs 56.07 [47.59, 89.93] mL, [113.67±16.81] g vs [127.14±22.99] g, all P < 0.05); and there were no significant differences in other left ventricular structural or functional parameters before and after treatment (all P > 0.05). In terms of right ventricular parameters, right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and right ventricular mass (RVM) were significantly increased after treatment ([144.52±25.14] mL vs [118.46±28.08] mL, [71.51±14.59] mL vs [55.62±15.93]mL, [35.05±7.31] g vs [30.43±5.95] g, all P < 0.05); and there were no significant differences in right ventricular function parameters such as right ventricular ejection fractionConclusion During long-term follow-up after treatment, the right ventricular functional parameter RVEF and myocardial strain of coronary artery CTO patients are stable, while the structural parameters RVEDV, RVESV and RVM are increased.