Objective To evaluate the prognosis of patients with novel coronavirus infection and myocardial injury by comparing the prognostic efficacy of echocardiography left ventricular ejection fraction,troponin,lactate dehydrogenase and their combination models.Methods The clinical data of patients with severe myocardial injury caused by novel coronavirus infection from December 2022 to January 2023 were retrospectively analyzed.The prognostic efficacy of patients with severe myocardial injury caused by novel coronavirus infection was evaluated by comparing the left ventricular ejection fraction,troponin and lactate dehydrogenase of echocardiography.Results 44 severe cases of novel coronavirus infection combined with myocardial injury were analyzed,of which 18 cases had a final prognosis of death and 26 cases had a final prognosis of improvement.After binary logistic analysis,left ventricular ejection fraction classification and lactate dehydrogenase were selected as independent related factors for the prognosis evaluation of patients(P<0.05).At the same time,troponin was added to establish a combination of two and three models according to the clinical requirements.The area under the ROC curve for the evaluation of patients'prognosis correlation was 0.776,0.902,0.904 and 0.917,respectively.Left ventricular ejection fraction combined with lactate dehydrogenase and left ventricular ejection fraction combined with troponin and lactate dehydrogenase(P=0.264),troponin combined with lactate dehydrogenase and left ventricular ejection fraction combined with troponin and lactate dehydrogenase(P=0.499),left ventricular ejection fraction combined with troponin and left ventricular ejection fraction combined with troponin and lactate dehydrogenase(P=0.022).Conclusion Echocardiographic left ventricular ejection fraction,troponin,lactate dehydrogenase and their combination models are all valuable for the prognosis evaluation of patients with novel coronavirus infection and myocardial injury.Among which the combination model of the three is the most significant for the prognosis evaluation of patients with novel coronavirus infection and myocardial injury.