Abstract: Objective To explore the value of ultrasound lung comets in assessing the illness severity of heart failure in elderly patients and its relationship with heart rate variability (HRV) and prognosis of patients. Methods A total of 95 cases of elderly heart failure in our hospital between January,2014 and June,2015 were selected as the research object.All of the patients received on bed lung ultrasound examination and comets number calculation before the treatment and were divided into group A (comets number ≥ 12,n=32) and group B (comets number<12,n=63) based on comets number.Cardiac function New York heart association (HYHA) grading and one-year survival rate were compared on the basis of follow-up.The relationships between ultrasound lung comets number and their HYHA grading,one-year survival rate and HRV were analyzed. Results Compared with group B,the ratio of HYHA class Ⅲ and Ⅳ patients in group A were higher,while the percentage of HYHA class Ⅱ patients was lower (P<0.05).The HRV indexes,such as standard deviation of all normal sinus RR intervals over 24 h (SDNN) and standard deviation of the averaged normal sinus RR intervals for all 5-mm segments (SDANN),one-year survival rate in group A were lower as compared with group B (P<0.05).Spearman correlation analysis results showed that ultrasound lung comets number of elderly heart failure patients was positively correlated with HYHA grading (r=0.886,P<0.05),while negatively correlated with one-year survival rate (r=-0.812,P<0.05);Pearson correlation analysis results showed a negatively correlated with SDNN and SDANN (r=-0.752,-0.748,P<0.05). Conclusion Ultrasound lung comets in the elderly heart failure patients are correlated with illness severity,HRV and prognosis,which can be used as reference on condition and prognosis of patients.