Electrocardiographic abnormalities in patients with COVID-19 pneumonia and raised interleukin-6

BACKGROUND: Cardiac injury is associated with high mortality in patients with COVID-19 infection. Electrocardiographic changes can give clues to the underlying cardiovascular abnormalities. Raised inflammatory markers like raised interleukin-6 (IL-6) are associated with arrhythmia, heart failure, and coronary artery disease. However, past studies have not highlighted the electrocardiographic abnormalities in patients with COVID-19 infection with raised IL- 6 levels. This study compared the electrocardiogram (ECG) changes in COVID-19 patients with high and normal IL-6 levels. METHODS: A retrospective analysis of ECG of 306 patients with COVID-19 infection was done, out of which 250 patients had normal IL- 6 levels, whereas 56 patients had raised IL-6 levels. IL-6 levels were measured in all the patients. Detailed clinicodemographic profile of all the serial COVID-19 patients admitted with moderate to severe COVID-19 pneumonia was noted from the hospital record section. Electrocardiographic findings and biochemical parameters of all the patients were noted. RESULTS: Out of 56 patients with raised IL-6 levels, 41 (73.2%) patients had ECG abnormalities compared to 177 (70.8%) patients with normal IL-6 levels. This difference was not statistically significant. However, ECG abnormality such as sinus tachycardia was significantly more common in patients with raised IL-6 levels than those with normal levels. Among patients with raised IL-6 levels who were discharged, 5 (16.6%) had sinus tachycardia, 2 (6.6%) had ST/T wave changes as compared to 15 (57.6%), and 10 (38.4%) who had tachycardia and ST/T wave change respectably succumbed to death. This difference was statistically significant. CONCLUSIONS: Sinus tachycardia followed by atrial fibrillation and right bundle branch block are common ECG changes in patients with COVID-19 infection with raised IL-6. The possible association of cardiac injury in patients with COVID-19 infection with coexisting raised IL-6 levels should be explored further.