Lyme Carditis Can Cause 3rd Degree Heart Block
Lyme carditis may rapidly progress to severe heart block.
3rd degree AV block can develop early and may require temporary pacing.
Prompt antibiotic treatment may reverse conduction abnormalities.
A case report entitled Electrocardiographic progression of acute Lyme disease describes a patient with Lyme carditis who developed rapidly progressive atrioventricular (AV) block requiring temporary pacing.
The patient presented with a syncopal episode without prodrome, along with shortness of breath and weakness.
According to Fuster and colleagues, “Three weeks prior to the presentation, he had experienced an ‘insect bite’ on his calf after being outside. A week later, he developed chills, sweats, myalgia, back pain, headache and fatigue.”
Lyme carditis and severe heart block
Lyme carditis was diagnosed based on:
- a pulse rate of 38 bpm
- high-degree AV block
- absence of ischemia
- clinical suspicion for Lyme disease
A temporary transvenous pacemaker was placed through the jugular vein, and the patient was admitted for cardiac monitoring and treatment.
Intravenous ceftriaxone was prescribed.
Most patients presenting with Lyme carditis and new onset arrhythmia do not remember a tick bite or have a clear exposure history.
Progression to 3rd degree AV block
The electrocardiogram evolved from high-degree AV block into complete 3rd degree AV block with a junctional escape rhythm.
By Day 5, the rhythm improved to 2:1 AV block with a narrow conducted QRS complex.
The temporary pacemaker was removed on Day 6.
By the second week, the electrocardiogram had returned to normal sinus rhythm.
The patient was discharged and instructed to complete 4 weeks of antibiotics.
According to the authors, “This is the first case in the literature that has captured the electrocardiographic evolution of Lyme carditis, day by day until complete resolution.”
Lyme carditis may occur without a classic rash
Fuster and colleagues emphasized that many patients with Lyme carditis do not recall a tick bite or develop a classic erythema migrans rash.
According to the authors:
- only 40% of Lyme carditis patients report erythema migrans
- new onset heart block may be the presenting feature
- clinical suspicion remains essential in endemic areas
Learn more about Lyme carditis symptoms and complications.
CDC recommendations for suspected Lyme carditis
The authors highlighted several CDC recommendations for patients with suspected Lyme carditis.
- Males are disproportionately affected by Lyme carditis.
- Patients ages 15–45 develop Lyme carditis more frequently.
- ECG evaluation is mandatory if Lyme carditis is suspected.
- Patients with unexplained heart block should be evaluated for tick exposure.
- Hospitalization is recommended for advanced AV block.
According to the authors, hospitalization is recommended for:
- 2nd degree AV block
- 3rd degree AV block
- 1st degree AV block with PR interval >300 ms
Why temporary pacing may be necessary
Lyme carditis can disrupt electrical conduction at multiple levels within the heart.
The most common cardiac manifestation is AV block, which may fluctuate rapidly between:
- 1st degree AV block
- 2nd degree AV block
- 3rd degree AV block
Progression may occur quickly and can become life-threatening if untreated.
Temporary pacing may stabilize patients until antibiotics reduce cardiac inflammation and conduction improves.
Learn more about heart complications associated with Lyme disease.
Frequently Asked Questions
Can Lyme disease cause 3rd degree heart block?
Yes. Lyme carditis can rapidly progress to complete 3rd degree AV block and may require hospitalization and temporary pacing.
Is Lyme carditis reversible?
In many cases, conduction abnormalities improve with prompt antibiotic treatment.
Do all Lyme carditis patients remember a tick bite?
No. Many patients do not recall a tick bite or develop a classic erythema migrans rash.
Can Lyme carditis require a pacemaker?
Temporary pacing may be necessary in severe cases, although permanent pacemakers are often avoided when treatment is started promptly.
What symptoms suggest Lyme carditis?
Symptoms may include palpitations, chest pain, fainting, dizziness, shortness of breath, or unexplained bradycardia.
Clinical Takeaway
Lyme carditis can present with rapidly progressive conduction abnormalities, including complete 3rd degree AV block.
Because many patients do not recall a tick bite or rash, clinicians should maintain suspicion when evaluating unexplained heart block in endemic regions.
Early recognition, hospitalization, cardiac monitoring, and antibiotic treatment may reverse life-threatening conduction abnormalities and prevent permanent cardiac damage.
Related Articles
These related articles explore Lyme carditis, cardiac complications, sudden cardiac death, and delayed diagnosis in tick-borne disease.
Males are disproportionately affected by Lyme carditis
How Lyme myocarditis may present in adolescents
Lyme disease misdiagnosis
Delayed Lyme disease diagnosis
Lyme disease symptoms guide
References
- Fuster LS, Gul EE, Baranchuk A. Electrocardiographic progression of acute Lyme disease. Am J Emerg Med. 2017.
- Centers for Disease Control and Prevention. Final 2012 reports of nationally notifiable infectious diseases. MMWR Morb Mortal Wkly Rep. 2013;62(33):669-682.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
Hooray for a proper diagnosis, right here in Ontario! I’d like to suggest that the treating doctors have this published in a journal read by Infectious Disease Doctors.
I agree with Denise. My following concerns are how many other lives can be saved if doctors learn and understand what lyme can really do and.. sadly, how many lives could have been spared had more doctors been educated sooner? So many lymies will become a statistic and a part of history one day when this modern day epidemic finally gets the exposure it so desperately needs.
Glad to see this. Lyme nearly killed my husband last June, after contracting Lyme carditis. He went into cardiac arrest after a 3-week ‘flu.’ The only reason he lived was that he was already in the cardiac ICU; the entire team jumped on him immediately and brought him back. (Thank God.) He was put on powerful IV antibiotics (ceftriaxone) for 4 weeks via a PIC line.
He’d had no rash. We never saw the tick that bit him, nor knew where on his body he’d been bitten. It was in May, tick nymph season. Four weeks earlier he had been on a camping trip in Maryland woods. A week after the trip ended, he fell ill with what seemed like the flu, but wasn’t contagious.
I grew suspicious as he grew weaker and weaker, until finally in the 3rd week of illness, I insisted he go to the ER because he simply couldn’t get out of bed and was grey as death.
He was immediately admitted with 3rd degree heart block and sent to cardiac ICU where staff began IV antibiotics.
They did not place a pacemaker, however, until after the code blue. Once he was defibrillated and revived, they immediately placed one.
It was a lesson learned. The military (this occurred at Walter Reed in Bethesda, MD) has since changed its Lyme carditis protocol to place a pacemaker at the outset of treatment with severe heart block, so that a similar scenario doesn’t happen again.
Thanks for this article and efforts to raise awareness of Lyme.
I recently had someone copy from the CDC’s site to find out the “terms” ….
Needless to say I’m wondering?
Does this only happen immediately after a tick bite, or can it happen down the road years later when as shown in studies Lyme can suddenly come awake after little or no signs or symptoms?
This can happen years later. I was bit by a tick in November 2020. It was embedded in my side and there was a redness around it when I saw it. I did not go to the doctor because the redness cleared and there was no bulls eye rash.
In early August 2022 I tested positive for Covid. Ten days later I was negative. Two weeks after Covid I became I’ll with a fever, headache, and cough. Thinking it was still Covid, I tested myself for Covid 3 days in a row and they were negative . August 21, I went to the ER and was diagnosed with long haul Covid. I never felt better as I was a bit feverish, headaches came and went and very fatigued in the days to come. On Sept9 I drove to the ER with heart palpitations high bp and a red warm rash on my leg and neck. After blood work and an EKG found nothing troubling, They sent me home and told me to follow up with a cardiologist. Two days later I return to the ER with slow heart rate (40-50bpm) I was admitted to the hospital with EKG showing 3rd degree heart block. Doctors started me on ceftriaxon right away and was rushed to surgery and needed a temporary pace maker. Lyme tests came back positive.
I am glad the doctors looked past COVID and Long COVID
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4395762/
I thought this article may help shed some additional light on this issue, although it could be put into layman’s terms.
Thanks for sharing the Pubmed link titles “Lyme Carditis—Diagnosis, Treatment and Prognosis”. It is encouraging to hear others address this all important issue.