Outcome and implications:
As the patient lost follow-up after 4 weeks, we do not have any data about the long-term outcome of our patient. New-onset AV node disease can develop from ischemic cardiac disease, cardiomyopathy, myocarditis, endocarditis, thyroid disease, and medications. [1,4] COVID-19 may contribute to the etiology of AV node conduction disruption. COVID-19 has been shown to contribute to and cause cardiovascular diseases in 19.7% of patients. [2] A study performed in June of 2020, analyzed the occurrence of varying cardiac arrhythmias in COVID-19 patients reported by 1,197 respondents. These issues ranged from atrial fibrillation (20.79% reported) and atrial flutter (5.42%) to AV block (13.57%), and bundle branch blocks (2.42%). [11]  Emerging case reports have shown that patients with COVID-19 have occasionally developed heart block. One case presented a 44-year-old male with new-onset diabetes and no cardiac history who tested positive for COVID-19 and experienced transient complete heart block. [1] Another case presented an 82-year-old male who presented with shortness of breath and a dry cough. He tested positive for COVID-19 and shortly after endotracheal intubation developed a complete heart block. This report also presented a 55-year-old male with no medical history who developed transient second-degree heart block on day six of admission after receiving a positive COVID-19, and a 43-year-old male with no medical history who tested positive for COVID-19 on day six of admission and developed intermittent complete heart block on day 24 of admission. [3] Additionally, a case was presented of a 10-year-old male with a 7-day history of fever, fatigue, cough, and diarrhea who developed first-degree heart block after 24 hours of admission that resolved overnight, and transient complete heart block on day three of admission. [10] None of these cases resulted in permanent heart block however they do demonstrate that transient conduction abnormalities may be seen in the setting of COVID-19.
While all degrees of AV block have been reported in COVID-19 patients, there have been few to no reports on patients developing permanent AV block from COVID-19 infections. In this case, we present a 36-year-old male with no previous significant medical history who developed permanent third-degree AV heart block. While the long-term effects of COVID-19 continue to be studied this case presents a previously unreported permanent complication of COVID-19. The patient had the vaccination before few months before his breakthrough infection. Therefore, it is doubtful that the vaccine played any role in the occurrence of his third-degree AV block. We cannot be 100% certain that his third-degree AV block was related to COVID-19 infection. However, the occurrence of these arrhythmias shorty after having COVID-19 infection with symptoms is highly suggestive of COVID-19 induced third-degree AV block. His MRI was negative for any scaring. However, with a spatial resolution of a cardiac MRI of 1.5 x 1.8 mm, [12] would be impossible to detect a small area of scarring in the AV node. Case series of 6 patients requiring permanent pacemaker insertion during their COVID-19 infection have been reported. [13] However, all these 6 patients were elderly patients with severe COVID-19 infection requiring hospitalization for very critical conditions. Our case is unique as the third-degree AV block occurred in a young person with previous vaccination who had only self-limiting mild upper respiratory symptoms.
Outcomes and Implications:  Permanent 3rd degree AV block in the setting of COVID-19 infection can occur in young patients. However, the long-term outcome is not known. The rule of pacemaker insertion in young asymptomatic patients remains unknown.
Conclusion:  Clinicians need to be aware of the occurrence of permanent high-grade AV block even in young patients with COVID-19 infection regardless of immunization status.  This condition can occur in patients with normal cardiac function and normal MRI. Future studies hopefully can shed light on the pathogenesis of this condition.