Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ KEY FEATURES +++ ESSENTIALS OF DIAGNOSIS ++ Flulike illness, or confirmed Lyme disease, followed by evidence of atrioventricular block Diagnosis is confirmed by the association of typical clinical features with serologic testing +++ GENERAL CONSIDERATIONS ++ Infectious disease caused by Borrelia burgdorferi, a tick-borne spirochete Male predominance 3:1 for cardiac Lyme disease Initial manifestations include: – Myalgias – Arthralgia – Fever – Headache – Erythema migrans Four to 10% of infected patients develop symptoms from transient cardiac involvement weeks to months after initial presentation The most common manifestation is conduction abnormality in the form of varying degrees of atrioventricular block Syncope due to complete heart block is common Diffuse ST-segment and T-wave changes and asymptomatic left ventricular dysfunction may be found, but congestive heart failure is rare Occasional patients develop symptomatic myocarditis or pericarditis +++ CLINICAL PRESENTATION +++ SYMPTOMS AND SIGNS ++ Cardiac features can be coincident with other early features of Lyme disease, including erythema migrans and neurologic abnormalities, or may be the only manifestation of infection Palpitations (common) Lightheadedness Syncope (common) Dyspnea Chest pain Some patients are asymptomatic +++ PHYSICAL EXAM FINDINGS ++ Bradycardia Cannon a waves in the jugular venous pressure in patients with complete heart block Congestive heart failure is uncommon Erythema migrans Monoarthritis Cranial nerve palsy or other findings of meningoencephalitis +++ DIFFERENTIAL DIAGNOSIS ++ Myocarditis due to other infectious agents Intrinsic conduction system disease +++ DIAGNOSTIC EVALUATION +++ LABORATORY TESTS ++ Lyme serology with enzyme-linked immunosorbent assay (ELISA) and/or Western blot analysis +++ ELECTROCARDIOGRAPHY ++ Varying degrees of atrioventricular block, which can progress to complete heart block in a short period of time Bundle branch block, fascicular block Nonspecific ST- and T-wave changes +++ IMAGING STUDIES ++ Chest x-ray: – Cardiomegaly may be present and is usually transient Echocardiography: – Mild cardiomegaly and/or mild left ventricular dysfunction – Pericardial effusion may be present – These changes are usually transient +++ DIAGNOSTIC PROCEDURES ++ Electrophysiologic testing is rarely required; typical findings include: – Heart block within the atrioventricular node, although heart block may occur at other levels within the conduction systems – Sinus node dysfunction may also be present Endomyocardial biopsy (rarely indicated) shows the following: – Lymphoid and plasmacytic infiltrates – Variable amounts of necrosis, fibrosis, and edema that are indicative of active myocarditis – Spirochetes have been isolated in some +++ TREATMENT +++ CARDIOLOGY REFERRAL ++ Atrioventricular block of any type Evidence of myocarditis or left ventricular dysfunction +++ HOSPITALIZATION CRITERIA ++ Symptomatic patients, including syncope High-grade or progressive ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.