Lyme disease, Lyme cardit, Reversible complete heart block

• Lyme disease also known as "Lyme borreliosis" [1]
• Lyme disease is a systemic illness caused by the spirochete Borrelia burgdorferi [3]
• caused by bacteria of the Borrelia type which is spread by ticks [1]
• The most common sign of infection is an expanding area of redness on the skin, known as erythema migrans [1]
  
• Blood test - Screening Lyme serology - positive [2]
• Lyme carditis is a complication of Lyme disease [3]
• The Lyme bacterium can infect all parts of the heart, including the conduction system around the atrioventricular node, the outer or inner membranes of the heart, the cardiac muscle [4]
• impairment of conduction system cause heart block [ 1st degree, 2nd degree and complete heart block]
• Ceftriaxone started after 24 hours rash is resolved [2]
• After 48 hours of observation, he underwent a temporary VVI (ventricular pacing and sensing mode) pacemaker insertion [2]
• On ceftriaxone, the AV block converted to first degree 2 days after starting antibiotics and then completely resolved by day 11, at which point the pacemaker was removed [2]
• He completed a total 21-day course of treatment with oral doxycycline [2]

References

1. Lyme disease - Wikipedia
2. Case of Reversible Complete Heart Block - The American Journal of Medicine, Vol 130, No 8, August 2017
3. Lyme carditis with complete heart block: management with an external pacemaker, Muhammad Ali Chaudhry. Pubmed
4. Lyme Disease and the Heart. - Peter J. Krause, Linda K. Bockenstedt. Circulation, 2013