PURPOSE: This study was conducted to explore the value of noninvasive assessment of bedside ultrasound in diagnosing cardiac changes of COVID-19. METHODS: We performed a retrospective study in 34 patients with COVID-19 and analyzed their clinical data, biochemistry test results (creatine kinase-MB [CK-MB], cardiac troponin I [cTnI] and C-reactive protein [CRP]), and parameters of cardiac ultrasound (left atrium [LA], left ventricular end-diastolic dimensions [LVDD], right atrium [RA], right ventricle [RV], main pulmonary artery [MPA], left ventricular ejection fraction [LVEF], tricuspid valve [TV], pulmonic valve [PV] and pulmonary artery systolic pressure [PASP]). We classified the patients based on their clinical symptoms: mild, moderate, severe, and critical groups, and compared the parameters. RESULTS: As the disease progressed, the parameters of both biochemical blood tests and cardiac ultrasound changed regularly, manifested as enlargement of LA, LVDD, RA, RV, and MPA and increase of PASP, CRP, CK-MB, and cTnI. Of these parameters, CRP, LA, LVDD, MPA, and PASP of the severe group were more notably elevated than those of the mild and the moderate groups (p<0.05). The critical group increased more markedly in CK-MB, cTnI, and RA than the other groups (p<0.05), and rose more sharply in CRP, LA, LVDD, RV, MPA, and PASP than the mild and the moderate groups (p<0.05). CONCLUSION: As the disease progressed, the patients had the enlarged heart with expanded pulmonary arteries and elevated PASP. Bedside ultrasound can be a noninvasive assessment of the above changes and a guidance of clinical treatment.