Can you die from Lyme disease? Yes. While rare, untreated Lyme carditis can cause fatal cardiac arrhythmias. Two New England cases demonstrate how diagnostic delays and waiting for test confirmation before starting antibiotics contributed to preventable deaths.

The Reality of Lyme Disease Mortality

Lyme disease can lead to acute and chronic illness. But deaths from Lyme disease can occur. “Death can occur when Lyme carditis is untreated,” wrote Marx, from the Centers for Disease Control and Prevention (CDC), in the Annals of Internal Medicine. “Before this report, only 9 fatal cases were reported in the literature.”

The CDC documented two additional fatal cases — both involving young to middle-aged adults with no prior cardiac history. Both patients had clear evidence of Lyme disease. Both had diagnostic testing ordered. Yet neither received timely antibiotic treatment.

Case 1: Waiting for an Infectious Disease Appointment

A 57-year-old man from Vermont presented to a primary care physician after one week of fever, fatigue, shortness of breath, and chest pain.

The evidence for Lyme disease included a disseminated erythema migrans rash, heart block, and a positive Lyme ELISA and IgM Western blot test. Yet the patient was not treated.

Eight days later, he presented to an emergency room with worsening symptoms. Physicians suspected Lyme disease, but antibiotics were not prescribed. Instead, a consultation with an infectious disease doctor was scheduled.

Only 12 days after his initial presentation — and before his scheduled appointment — the patient was found unresponsive.

This case exemplifies medical abandonment. The patient had classic findings: EM rash, cardiac symptoms, positive serology. Yet treatment was deferred to a specialist appointment that never occurred.

Case 2: Before the First Dose of Antibiotics

A 49-year-old woman from Massachusetts presented to an emergency department with severe headache, nausea, and vomiting. She was diagnosed and treated for a headache.

Two weeks later, she saw her primary care physician and reported two episodes of syncope with bowel and bladder incontinence, persistent fatigue and nausea, and shortness of breath. An ECG during the office visit showed atrioventricular dissociation. Lyme disease tests were ordered.

Two days later, Lyme disease test results revealed a positive ELISA and IgM Western blot. She was prescribed doxycycline. But the next day — before she took the first dose — her cardiac monitoring recorded atrioventricular dissociation evolving to ventricular tachycardia.

She died before taking a single antibiotic pill.

Pathology Confirmed Lyme Carditis

In both patients, postmortem evaluation of heart tissue found lymphohistiocytic pancarditis with immunohistochemical and molecular evidence of Borrelia burgdorferi. Spirochetes were directly visualized in endocardial tissue from the Massachusetts patient.

The pathology proved what clinical judgment should have recognized earlier: active Lyme carditis requiring immediate treatment.

Why These Deaths Were Preventable

Lyme carditis was high on the list of possible diagnoses in both cases. Yet neither patient was treated empirically with antibiotics when Lyme disease testing was performed.

Guidelines recommend simultaneous initiation of empirical antibiotic therapy and Lyme serologic testing when Lyme carditis is suspected. “Lyme carditis can progress rapidly,” explains Marx. “Waiting for confirmatory diagnostic therapy to initiate antibiotic treatment may result in negative outcomes.”

These deaths illustrate a pattern seen across Lyme disease care — diagnostic hesitation, delayed treatment, and over-reliance on test confirmation before acting. When carditis is on the table, waiting can be fatal.

The Pattern of Diagnostic Delay

Both cases share disturbing commonalities:

• Multiple healthcare encounters before diagnosis
• Clear clinical evidence of Lyme disease (EM rash, cardiac symptoms)
• Testing ordered but treatment delayed until confirmation
• Death occurring during the wait for results or specialist appointments

This pattern reflects broader challenges in medical dismissal of Lyme disease. When cardiac involvement is present, hesitation kills.

What Should Have Happened

In both cases, antibiotics should have started immediately when Lyme carditis entered the differential diagnosis:

• Vermont patient: Should have received IV ceftriaxone at initial presentation with EM rash + cardiac symptoms
• Massachusetts patient: Should have received antibiotics when syncope + AV dissociation developed, not after waiting for test results

The fundamental error was treating Lyme carditis as a diagnosis requiring laboratory confirmation rather than a medical emergency requiring empiric treatment.

Clinical Perspective

In my practice, I emphasize that Lyme carditis should be treated as a medical emergency. When a patient presents with new conduction abnormalities in a Lyme-endemic area — especially a younger patient — empiric antibiotics should begin immediately, not after serologic confirmation.

I’ve seen too many patients dismissed at initial presentations, told their symptoms are anxiety or stress, sent home without treatment. Most survive because Lyme carditis deaths are rare. But these two cases prove that diagnostic hesitation can be fatal.

The lesson is clear: if you’re considering Lyme carditis, start antibiotics. The downside of empiric doxycycline or ceftriaxone is minimal. The downside of waiting is death.

These cases also highlight why patients must advocate for themselves. If you have cardiac symptoms after a tick bite or in an endemic area, insist on immediate treatment. Don’t accept “let’s wait for the test results.” Document the refusal if physicians won’t treat. Your life may depend on it.

Frequently Asked Questions

Can you die from Lyme disease?

Yes. Although rare, untreated Lyme carditis can cause fatal cardiac arrhythmias. The CDC has documented multiple deaths from Lyme carditis, most involving delayed diagnosis or treatment. Deaths are preventable with prompt antibiotic therapy.

How does Lyme disease affect the heart?

Borrelia burgdorferi can infiltrate heart tissue, disrupting the electrical conduction system. This can cause heart block ranging from mild to complete, with the most severe cases progressing to fatal arrhythmias like ventricular tachycardia.

Should antibiotics be started before Lyme test results come back?

Yes — when Lyme carditis is suspected. Guidelines recommend empiric antibiotic treatment at the same time serologic testing is ordered. Waiting for results has contributed to preventable deaths. Both fatal cases documented by the CDC involved delays waiting for test confirmation.

How quickly can Lyme carditis become life-threatening?

Rapidly. In the cases described by Marx, one patient died within 12 days of initial presentation. Atrioventricular block can progress from mild to fatal within hours to days. This rapid progression makes empiric treatment critical.

Is Lyme carditis more dangerous in certain age groups?

Fatal cases have occurred in adults of various ages. However, younger patients with no prior cardiac history who develop sudden conduction abnormalities should raise immediate suspicion for Lyme carditis. The Vermont patient was 57, the Massachusetts patient was 49 — both previously healthy.

What are the warning signs of Lyme carditis?

Warning signs include chest pain, shortness of breath, palpitations, syncope (fainting), lightheadedness, and fatigue — especially when occurring after tick bite or in endemic areas. Any new cardiac symptoms warrant immediate evaluation and consideration of empiric Lyme treatment.

How many people have died from Lyme carditis?

The CDC documented 11 fatal cases in the literature as of 2019. The true number is likely higher due to underreporting and misdiagnosis. Most deaths involve diagnostic delays or failure to treat empirically when Lyme carditis is suspected.