Lyme Carditis: A Rare Case of Heart Failure in the Absence of Ischemic Heart Disease

Introduction

Lyme disease, caused by the spirochete Borrelia burgdorferi and transmitted through tick bites, is the most prevalent tick-borne illness in the United States [1]. The risk of human infection is linked to the geographic distribution of the vector tick species and human behaviors that elevate the likelihood of tick bites. The primary clinical manifestation of Lyme disease is a patch of erythema or migrating redness. Bull’s eye rash is often diagnostic of Lyme disease, but Lyme rashes show tremendous variation [2]. Blisters and necrotic and hemorrhagic lesions have also been reported. Beyond the skin lesions, Lyme disease manifests with a spectrum of symptoms affecting various organ systems. Initial symptoms may include fever, chills, fatigue, headache, muscle and joint aches, and swollen lymph nodes. If left untreated, the infection can progress to severe and potentially chronic complications, impacting the joints, nervous system, and cardiovascular system. Cutaneous, articular, cardiac, neurological, or psychiatric manifestations may also be an initial manifestation.

Dissemination of Borrelia burgdorferi can induce cardiac infections, most commonly affecting the conduction system and, in rare instances, cardiac muscle and cardiac blood vessels or heart valves [3]. Cardiac involvement can disrupt the intricate cardiac conduction system, leading to conditions like atrioventricular block [4]. Simultaneously, the cardiac muscle may succumb to myopericarditis, an inflammation affecting both the myocardium and pericardium, leading to symptoms such as chest pain [4]. While rare, bacterial infiltration into cardiac blood vessels or heart valves poses risks of vascular complications and valvular dysfunction [5]. Cardiac involvement typically occurs within weeks to months after a tick bite, with the most reported cases in July, and less than 5% of Lyme carditis cases manifest in winter months [6]. We present a unique case of Lyme carditis manifesting as acute heart failure in late December.

Case Report

CLINICAL COURSE:

An electrocardiogram (EKG) displayed T-wave flattening in the anterolateral pre-cordial leads (Figure 1). Initial investigations included a chest X-ray, indicating pulmonary edema and inter-stitial infiltrates (Figure 2). Laboratory analysis revealed a significantly elevated B-type natriuretic peptide (BNP) of around 2800 pg/mL, along with mildly elevated troponins (128 ng/L). Consequently, the patient received ceftriaxone and doxycycline for presumed pneumonia, as well as intravenous furosemide therapy for acute heart failure exacerbation. Additionally, a 48-hour heparin infusion was initiated due to concerns regarding underlying acute coronary syndrome (NSTEMI). Subsequently, she was transferred to our hospital for further management.

Upon arrival, her condition had stabilized, with the resolution of supplemental oxygen requirement and improvement in exertional dyspnea following diuretic therapy. However, she exhibited gradually worsening sinus bradycardia, with a heart rate in the 50s and significant hypotension (systolic blood pressure consistently below 90 mmHg). Telemetry monitoring and EKGs throughout the hospitalization revealed absence of AV block. Importantly, she continued to deny chest pain, shortness of breath, orthopnea, and paroxysmal nocturnal dyspnea. She did not show signs of end-organ dysfunction evidenced by normal mental status, lactate levels, urine output, renal, and liver functions. Her thyroid-stimulating hormone and 8 a.m. cortisol profiles were also normal (0.039 uIU/ml and 17.1 ug/dL, respectively). The respiratory viral panel result was unremarkable. Point-of-care ultrasound (POCUS) of the heart revealed a hypokinetic anterior left ventricular (LV) wall and mildly reduced ejection fraction by visual estimation, while the inferior vena cava (IVC) parameters were within the normal range and showed respiratory variation. Of note, her prior EKGs and echocardiograms were normal. Lyme serologies were ordered a few days after presentation due to the unclear etiology of new heart failure and in the setting of this persistent bradycardia.

Due to persistent hypotension, reaching a nadir of 76/50 mmHg (MAP of 59), she was transferred to the Cardiovascular Intensive Care Unit (CVICU) for monitoring and potential pressor support. Lyme IgM and IgG titers followed by Western blot returned positive, leading to the continuation of ceftriaxone therapy for Lyme carditis. Formal echocardiography demonstrated mildly depressed LV systolic function with an ejection fraction of 50% and akinetic anteroseptal, anterolateral, and anterior LV walls (Video 1A, 1B). A coronary computed tomography angiogram (CTA) ruled out an ischemic etiology and coronary artery disease, revealing a coronary calcium score of 0. Over the following days, the patient’s condition gradually improved, with stabilization of blood pressure and heart rate, leading to her discharge on an extended course of intravenous ceftriaxone therapy (28 days) for the treatment of Lyme cardiac disease, manifested as myocarditis and cardiomyopathy. Cardiac MRI or endomyocardial biopsy were not pursued given the patient’s remarkably good clinical response to treatment. She was discharged on 14-day Holter monitor, showing absence of AV block.

Discussion

Initially described in 1980 by Steere and colleagues, Lyme cardiac disease is an infrequent manifestation of early Lyme disease dissemination, occurring in approximately 1% of patients [3,5]. The predominant manifestation is acute fluctuating heart block, with varying degrees of severity. Additional documented manifestations encompass EKG changes such as T-wave abnormalities, ST-segment changes, and QT-interval prolongation. Conversely, manifestations in the form of cardiomyopathy, pericarditis, and myocarditis are less prevalent when compared to conduction abnormalities. The specific signs and symptoms of Lyme cardiac disease depend on the cardiac manifestation. Patients may exhibit lightheadedness, pre-syncope, or syncope with palpitations in the case of heart block. Chest pain and shortness of breath may manifest with pericardial involvement and myocarditis, while an acute exacerbation of heart failure is possible with cardiomyopathy. A case of heart failure from Jarisch-Herxheimer reaction in patient with early Lyme disease following treatment has also been reported [7].

The diagnosis of Lyme cardiac disease relies on a combination of cardiac manifestations and clinical or serologic evidence of Lyme disease [5]. Serologic testing involves an initial antibody screening, followed by confirmatory testing using Western blot or other orthogonal tests if positive. Cardiac-related symptoms, such as dizziness, syncope, and overt heart failure exacerbation, are indications for echocardiographic evaluation and contribute to the diagnostic process. EKGs play a crucial role in diagnosing conduction abnormalities. A diagnosis of myocarditis or pericarditis may be considered if serologic testing is positive in a suggestive clinical scenario. Serological test of Lyme disease may be confirmed with Western blot, which takes around 48–72 hours. Although further evaluation with cardiac MR may be useful in certain circumstances, it is not routinely performed.

One distinctive aspect of this case is the patient’s atypical presentation of Lyme carditis. Traditionally, Lyme carditis is characterized by atrioventricular block and conduction abnormalities. However, in this instance, the patient presented with decompensated heart failure symptoms despite having a previously normal ejection fraction. Additionally, echocardiographic assessment revealed notable wall motion abnormalities, a feature less commonly observed in Lyme carditis cases. This unique presentation underscores the importance of considering Lyme carditis in the differential diagnosis of cardiac symptoms deviating from the classic clinical picture.

This case report presents a unique clinical scenario of Lyme carditis, challenging the conventional seasonal trends associated with its manifestation. While Lyme disease is predominantly contracted during the summer months due to heightened outdoor activities and increased tick exposure, the development of Lyme carditis can extend beyond this seasonal pattern. Typically emerging in the later stages of Lyme disease, often months after the initial tick bite, Lyme carditis is less commonly considered in the differential diagnosis during winter. However, this case serves as a noteworthy reminder for healthcare providers in regions with a high incidence of Lyme disease, such as West Virginia and surrounding states.

The mainstay of treatment of this disease is antibiotics. The choice of route of administration may largely depend on the severity of symptoms. For mild asymptomatic carditis, oral doxycycline or amoxicillin may be administered for a duration of 21 days. Severe presentations normally require 21-day course of intravenous ceftriaxone. Patients are usually expected to have full recovery from disease after 1–6 weeks, as demonstrated in a recently published case where a 70-year-old patient with Lyme carditis achieved full recovery within 3 weeks antibiotics therapy [8].

Conclusions

This case underscores the need for heightened clinical suspicion of Lyme carditis year-round, particularly in regions with a high prevalence of Lyme disease. The atypical clinical presentation observed in this case is a valuable reminder for health-care providers to consider Lyme carditis in patients presenting with cardiac symptoms, even when such presentations occur outside the conventional seasonal pattern of Lyme disease transmission. Timely recognition and appropriate management are paramount in ensuring optimal outcomes for patients with Lyme carditis.