Ahlam Al Awadhi1, Fatima Al Kendi2, Mohammed Ahmed Siddiqui3, Moutaz El Kadri1, Omar Al Falasi1, Mohammad Matar Almehairi2

1Sheikh Khalifa Medical City, Abu Dhabi, United Arab Emirates, 2Tawam Hospital, Al Ain, United Arab Emirates, 3Al Ain Hospital, Al Ain, United Arab Emirates

Background:
Myocardial ischemia, myocarditis, arrhythmia and cardiac arrest were well-recognized cardiac complications of COVID-19 infection. Majority of cardiac arrhythmias associated with COVID-19 infection were transient and insertion of cardiac device was rarely required. We aim to study the clinical outcomes of COVID-19 infected patients who developed complete heart block and required insertion of pacemakers.

Method(s):
A retrospective chart review study was conducted in three hospitals with electrophysiology (EP) services in the Emirate of Abu Dhabi (Sheikh Khalifa Medical City (SKMC), Tawam Hospital and AlAin Hospital).  We included all patients who required insertion of cardiac implantable electronic device (CIED) during the period of 1st March to 10th of August, 2020. Clinical and laboratory data of COVID-19 infected patients with complete heart block were collected and descriptive analysis was used.

Result(s):
59 patients required device implantation during study period. The mean age was 62.5 years, 72.8% were males and non-nationals (61%).  The majority of patients [49 (83%)] required urgent cardiac device implantation such as pacemaker (38.9%%), implantable cardioverter-defibrillator (ICD) (25.4%) and cardiac resynchronization therapy CRT-D (8.5%). Three patients (5%) from the cohort had COVID-19 infection and complete heart block. 

Case 1: a 40 years old female, previously healthy, diagnosed with asymptomatic COVID-19 infection and treated with azithromycin 500g, hydroxychloroquine (HCQ) 200 mg, BID and favipiravir oral 600 mg, TID for 3 days. Then she developed asymptomatic bradycardia and complete heart block (CHB) on ECG. Laboratory data including complete blood count, renal function, HbA1c, thyroid and liver function tests were all normal. She underwent permanent pacemaker insertion as she had persistence CHB despite negative COVID test and cardiac magnetic resonant was not done.

Case 2: 62 years old male, known to have hypertension and diabetes mellitus type 2, with baseline ECG of asymptomatic first-degree heart block and right BBB. He was admitted with severe COVID-19 pneumonia and started on HCQ and favipiravir. On 3rd admission day, he was diagnosed with CHB, and developed congestive heart failure requiring ICU care and non-invasive ventilation. He underwent temporary transvenous pacemaker followed by dual champers pacemaker insertion after 2 negative COVID test. Day 2 post procedure, He had dislodgement of atrial lead due to coughing that was confirmed with chest X ray and atrial interrogation. Interestingly repeated COVID-19 test was positive post procedure and total duration of viral shedding was 43 days.

Case 3: 70 years old male, known to have hypertension. He was admitted with moderate COVID-19 pneumonia and required ICU care for acute respiratory failure. ECG on admission showed high degree heart block 2 to 3 and underwent temporary pacemaker insertion. He was treated with camostat and Favipiravir for 10 days and viral shedding for 18 days. Thyroid function test and electrolytes were normal. Permanent pacemaker inserted while patient had positive COVID-19 test.

Conclusion(s):
Complete heart block is a rare complication in COVID -19 infected patients. Pacemaker insertion was required for three patients as CHB persisted despite resolution of infection and discontinuation of HCQ. The association between COVID-19 infection and cardiac conduction system need to be further elucidated by larger studies and longer follow up.