An Unusual Case of Lyme Carditis With Persistent Third-Degree Heart Block

Abstract

Lyme’s carditis and neuroborreliosis are common manifestation of disseminated Lyme disease. However, third-degree atrioventricular blocks with Lyme’s carditis requiring permanent pacemaker with neuroborreliosis and Lyme’s disease-associated immunodeficiency are uncommon. Here we present a case of 64-year-old female presenting with neurological symptoms and electrocardiogram changes suggestive of complete heart block with no improvement in the degree of heart block with intravenous antibiotics, requiring permanent pacemaker implantation and course complicated by fungemia.

Introduction

Lyme disease is a common tick-borne infection in the United States, caused by spirochete Borrelia species (sp.). Disseminated Lyme disease results from untreated early Lyme disease and may involve cardiac, neurological, and musculoskeletal organ systems. Lyme’s carditis occurs by direct invasion of the heart tissue by a spirochete. It most commonly presents with conduction defects progressing rapidly from first- to third-degree heart blocks and life-threatening arrythmia (like ventricular tachycardia). ¹ Here we present a case of disseminated Lyme disease with potential immunosuppression and persistent complete heart block.

Case

A 64-year-old female was brought to the emergency department by her son with complaints of altered sensorium, first noticed 4 days back, subjective fevers, chills, and increased night sweating. The patient had a formed rash on her legs, noticed 4 days back, for which her primary care physician prescribed cephalexin. No recent travel/hikes; patient lives in the District of Columbia with no significant participation in outdoor activities. On admission, the patient had a temperature of 103.1 °F, a blood pressure of 107/65 mmHg, and a heart rate between 40 and 60 beats per minute. Pertinent examination findings were disorientation to time and date, regularly irregular rhythm, and irregular first and second heart sounds with no appreciable murmurs. Initial electrocardiogram showed sinus rhythm with a ventricular rate of 54 beats per minute, complete heart block, junctional escape rhythm, right bundle branch block, and left anterior fascicular block. Initial blood work showed blood urea nitrogen of 26 mg/dL, creatinine 1.58 mg/dL, magnesium 1.58 mg/dL, troponin 0.155 Ng/ml, white blood cell counts of 12.3 × 109, urine routine microscopy was positive for >500 glucose, a moderate amount of blood, and a large number of leukocytes. Blood and urine cultures drawn on the day of admission grew candida glabrata in two sets. Two computed tomography scans of the head done 48 hours apart without contrast were negative for acute infarct/hemorrhage. The patient was placed on a transcutaneous pacemaker. Lyme serology tested positive for immunoglobulin G (IgG) blot (5 IgG bands present). The patient received a 3-week antifungal treatment and 2-week intravenous (IV) ceftriaxone. The transvenous pacer showed resolution of junctional rhythm with a heart rate ranging between 40 and 50 beats per minute and persistence of complete heart block (Figure 1) for which a permanent pacemaker was inserted. The patient’s sensorium improved, but she continued to experience generalized fatigue and myalgias.

Figure 1.

Electrocardiogram post transvenous pacer shows atrial-sensed, ventricular-paced rhythm.

Discussion

Disseminated Lyme disease is a sequela of untreated early stages and may involve multiple organ systems, including some degree of immunosuppression that predisposes patients to other infections. The pathophysiology of disseminated infection lies in the ability of the spirochete to disseminate through the lymphatics and blood across different organ systems. Lyme disease affects the immune system by altering the antigen-presenting cells (dendritic cells human leukocyte antigen DRs), thus hindering the immune system response to Borrelia. Instead, immune cells cross-react and affect neighboring healthy host cells. ² Borrelia is also observed to form a biofilm or biofilm-like material responsible for antibiotic resistance, evading immune response, and chronic persisting symptoms. ³ More invasive forms of borreliosis express multiple plasminogen-binding surface proteins that degrade fibronectin (a component of the extracellular matrix) and induce the release of metalloproteases, causing basement membrane degradation, all of which assist in dissemination. ³ Lyme’s carditis is one of the common cardiac manifestations of disseminated Lyme disease. Pathogenesis involves direct invasion by spirochetes and an associated inflammatory response. ⁴ Cardiac manifestations are most commonly due to the involvement of the conduction pathways (occurring at any level), with others being myocarditis, left ventricular failure, and pericarditis. Four to ten percent of patients develop some form of carditis and about 1% progresses to second- or third-degree heart blocks. ¹ Conduction defects usually resolve between 3 and 42 days, with complete blocks resolving to lesser degree blocks (usually within a week) and other lesser degree blocks resolving within 6 weeks. ¹ Treatment includes oral/IV antibiotics and temporary or permanent pacemakers depending on the degree of atrioventricular (AV) blocks. ⁵ The literature review reports very few cases of Lyme’s carditis requiring a permanent pacemaker, with over 90% recovering completely.^1,4 Case series report all patients with Lyme’s carditis improving and none requiring permanent pacemaker for high-degree AV block. ⁶ Gender predominance is varied among reported cases, with some reporting third-degree heart blocks more common in males and others in females with the commonly affected age group of 10 to 45 years.^1,4

Neuroborreliosis is another manifestation of disseminated Lyme disease. Patients may present with ataxia, paraparesis, sphincter dysfunction, Parkinson-like symptoms, confusion, and cognitive impairment. Spread is through the paracellular route of translocation and is usually responsible for meningitis, perivascular involvement, vasculitis, neuritis, and rare cases of encephalitis and myelitis. ³ Symptoms usually subside with antibiotic treatment, with few patients having chronic cognition defects. Even post-treatment patients can continue to experience fatigue, musculoskeletal pain, and cognition defects, which may wax and wane for years, known as post–Lyme disease treatment syndrome. ⁷

Conclusion

Our patient’s unusual presentation of disseminated Lyme’s disease makes it an intriguing case: leg erythema and swelling, subjective chills, and night sweats could be attributed to an early presentation of localized Lyme’s disease, altered mentation, a manifestation of neuroborreliosis, altered immunity predisposing to fungemia (with coexisting diabetes), and asymptomatic carditis not resolving with IV antibiotics, and requiring a permanent pacemaker.