Electrocardiographic features of patients with COVID-19 pneumonia

•We evaluated ECG features of patients hospitalized for COVID-19 pneumonia.•New ECG abnormalities reflected a wide spectrum of cardiovascular complications.•The most common manifestations were signs of pericarditis and atrial fibrillation.•ECG abnormalities showed a late onset from hospitalization.•ECG abnormalities seem to follow a separate course from the respiratory infection. . The electrocardiographic (ECG) changes which may occur during hospitalization for COVID-19 have not yet been comprehensively assessed. . We examined 50 patients admitted to hospital with proven COVID-19 pneumonia. At entry, all patients underwent a detailed clinical examination, 12-lead ECG, laboratory tests and arterial blood gas test. ECG was also recorded at discharge and in case of worsening clinical conditions. . Mean age of patients was 64 years and 72% were men. At baseline, 30% of patients had ST-T abnormalities, and 33% had left ventricular hypertrophy. During hospitalization, 26% of patients developed new ECG abnormalities which included atrial fibrillation, ST-T changes, tachy-brady syndrome, and changes consistent with acute pericarditis. One patient was transferred to intensive care unit for massive pulmonary embolism with right bundle branch block, and another for non-ST segment elevation myocardial infarction. Patients free of ECG changes during hospitalization were more likely to be treated with antiretrovirals (68% vs 15%, p = 0.001) and hydroxychloroquine (89% vs 62%, p = 0.026) versus those who developed ECG abnormalities after admission. Most measurable ECG features at discharge did not show significant changes from baseline (all p>0.05) except for a slightly decrease in Cornell voltages (13±6 vs 11±5 mm; p = 0.0001) and a modest increase in the PR interval. The majority (54%) of patients with ECG abnormalities had 2 prior consecutive negative nasopharyngeal swabs. ECG abnormalities were first detected after an average of about 30 days from symptoms’ onset (range 12–51 days). . ECG abnormalities during hospitalization for COVID-19 pneumonia reflect a wide spectrum of cardiovascular complications, exhibit a late onset, do not progress in parallel with pulmonary abnormalities and may occur after negative nasopharyngeal swabs.