Background: The coronavirus disease 2019 (COVID-19) pandemic poses broad challenges to healthcare systems and providers. The manifestations of this disease are still being described in a variety of different contexts and patient populations. Results: We report the case of a neonate who demonstrated COVID-19 after surgical correction of transposition of the great arteries. In addition, the patient demonstrated an evolving and persistent tachyarrhythmia consistent with neither the most likely postoperative complications nor typical COVID-19. Discussion: The patient had negative preoperative testing for the virus and presented with profound oxygen desaturation and respiratory failure several days postoperatively. This raised concern for a complication of his arterial switch operation. It was found that one of the patient's caregivers was an asymptomatic carrier of COVID-19, and imaging ruled out intracardiac shunting. After initiating treatment for COVID-19, the patient's oxygen requirements and need for anti-arrhythmic agents improved. Conclusion: We propose that, despite negative preoperative testing, coronavirus infection may present as refractory tachyarrhythmia, and may be considered along with surgical complications as a cause for unexplained hypoxemia postoperatively.