Cohort study to assess the prevalence of prolonged QT and arrhythmias in critically ill patients during the early phase of the COVID-19 pandemic.

Introduction: Patients with SARS-CoV-2 infection may present cardiovascular involvement including myocarditis, arrhythmias and QT interval prolongation. Our objective was to evaluate the impact of COVID-19 and its treatment on ventricular repolarization and development of arrhythmias in critically ill patients.

Methods: Retrospective cohort study of critically ill COVID-19 patients during a 3-month period in whom at least one ECG was available. Relevant clinical data and specific treatment administered for COVID-19 were recorded. Prolonged QTc was considered prolonged when it measured ≥ 460 ms in women and ≥450 ms in men. The incidence and type of arrhythmias during the same period were recorded.

Results: A total of 77 patients with a mean age of 62 ± 13 years, 20 women and 57 men, were evaluated. Sixty percent of the patients were hypertensive, 52% had a BMI > 30, and 70% developed acute renal failure during admission. Some 56% of the patients presented QTc prolongation. Forty-four percent presented some type of arrhythmia during their stay in the ICU, 21% of which were atrial arrhythmias. Overall mortality was 53%, with no differences between patients with or without prolonged QTc.

Conclusions: In our series, a high proportion of critical patients with COVID-19 presented prolonged QTc and arrhythmias. The factors involved have been related to the elevation of cardiac biomarkers, the myocardial involvement of the virus and concomitant medication received in the ICU.