Abstract
We report an unusual clinical presentation of Lyme carditis in a previously healthy 20-year-old black woman without any epidemiologic history of Lyme disease, fulminant in nature, involving a heart valve necessitating emergent mitral valve replacement, and requiring further surgical intervention because of the development of pericardial effusion and tamponade. A dilated right ventricle with normal contractility and severe tricuspid regurgitation with increase in the right atrial size diagnosed later remains under close surveillance
Introduction
Lyme borreliosis is a tick-borne bacterial infection caused by spirochete Borrelia burgdorferi. Lyme disease, originally described by Steere and associates [1] in 1977, is characterized by the diagnostic unique annular rash of erythema chronicum migrans accompanied by nonspecific systemic pathology. Cardiac manifestations occur in 8% to 10% of reported cases, but probably go undetected in many cases [2–4]. Lyme carditis was originally described as a mild, self-limited carditis, involving primarily the conduction system, although recent reports suggest that it may be more serious than previously suspected [3, 4], and may lead to heart failure and probably congestive cardiomyopathy [5, 6]. Nonetheless, Lyme carditis involving cardiac valves has not been reported previously [6]. We report an unusual clinical presentation of Lyme carditis, fulminant in nature, involving a heart valve necessitating emergent mitral valve replacement, and requiring further surgical intervention because of the development of pericardial effusion and tamponade
A previously healthy 20-year-old black woman without any epidemiological history of Lyme disease had consulted her physician with complaints of cough productive of yellowish sputum, chest pain, dyspnea, and occasional palpitations. There was no pharyngitis, adenopathy, arthritis, or rash. A physical examination was unremarkable with blood pressure 100/60 mm Hg, heart rate 90/min, and body temperature 98.6°C. Her chest x-ray was normal. The electrocardiogram showed a sinus rhythm with a first degree atrioventricular block. She was prescribed clarithromycin. A Lyme titer had been obtained that was positive to 6.33 enzyme-linked immunosorbent assay units. She had a western blot positive for the immunoglobulin G (IgG). Seven days later she was admitted to a hospital with severe respiratory distress syndrome requiring intubation and ventilatory support. Subsequently, she underwent tracheostomy and continued to be on mechanical ventilatory support, and was treated with broad spectrum antibiotics. An echocardiogram revealed initially moderate and later on severe mitral insufficiency. After two weeks of mechanical ventilatory support through tracheostomy she was emergently transferred to our hospital for further treatment. Repeat echocardiogram at our center confirmed ruptured chordae and severe mitral insufficiency. She was recommended to undergo emergent mitral valve surgery. An intraaortic balloon pump was inserted preoperatively from the right common femoral artery. At operation, all chordae arising from medial papillary muscle attaching to the anterior and partly to the posterior leaflets were ruptured. The left atrium was not dilated. The anterior leaflet was resected followed by the mitral valve replacement with a 27 mm St. Jude Medical (St. Jude Medical, Inc, St. Paul, MN) mechanical valve. The postoperative course was uneventful and she was discharged home with Coumadin therapy. Her laboratory findings at our center were as follows: antinuclear antibody, negative; cardiolipin antibody (IgG), negative; RPR, nonreactive; treponema pallidum antibody, negative; Legionella antibodies (IgG, IgM, IgA), negative; mycoplasma pneumoniae IgG, IgM, seropositive; antistreptolysin O (ASO), positive (titer 201); Lyme antibodies (IgG, IgM), positive; Lyme antibodies with enzyme linked fluorescent immunology (at the State Department of Diagnostic Immunology Laboratory [SDDIL]), reactive (antibody index = 1.96); Lyme immunoblot assay (at SDDIL), reactive (6 antigenic bands in IgG probe). Histopathology of the anterior mitral leaflet showed severe myxoid degeneration with infiltration of lymphocytes without any evidence of fibrinoid exudate and Aschoff bodies
One month after the discharge from our hospital the patient presented with complaints of upper quadrant abdominal pain, nausea, and vomiting. The abdominal ultrasound had incidentally revealed a pericardial effusion and she was transferred to our center for treatment. International Normalized Ratio upon admission was 1.9. Echocardiogram showed a large amount of pericardial effusion with right ventricular collapse in diastole. The left ventricular systolic function was preserved with good function of the mechanical valve. The patient underwent a left anterior thoracotomy and pericardial window for a pericardial effusion with tamponade. Nine hundred milliliters of serous fluid was evacuated from the pericardial cavity and the chest was closed leaving a drainage tube in the pericardial sac. On the first postoperative day the repeat echocardiogram showed the persisting depression of right ventricular function with a moderate amount of tricuspid regurgitation. The transesophageal echocardiography on the second postoperative day revealed a dilated right ventricle with normal contractility as well as flail chordae of the tricuspid valve and severe tricuspid regurgitation with an increase in right atrial size. The culture of her blood, urine, and pericardial fluid did not show any bacteriologic growth. Pericardial fluid neither did grow acid fast bacilli nor fungus after 21 and 56 days, respectively. Histopathology of pericardial specimen showed the evidence of lymphoplasmacytic pericarditis. Warthin-Starry stain for spirochete and special fungal stain were negative. Aschoff bodies were also absent. Postoperatively the patient did well, however, her chest tube was in longer because of increased serous drainage, and on the eighth postoperative day she was discharged home in good condition. Eleven months later, she remains well
Comment
Although it can cause acute myocarditis, the spectrum of cardiovascular manifestations associated with Lyme disease is no longer limited to its early stage [5]. In addition to the absence of the history of tick bite and cutaneous manifestations (erythema migrans) the areas of ambiguity include the lack of classic Lyme disease symptoms—fever, malaise, headache, mild neck stiffness, and arthralgia. The presence of the first degree heart block was the only clue to suspect Lyme disease and positive serologic tests favored the diagnosis of Lyme disease during the initial visit of our patient to her family physician. Despite the administration of clarithromycin, the acute development of respiratory distress syndrome and cardiomyopathy was quite unexpected in the case of Lyme disease. Despite a mild positive ASO titer (201), the absence of fibrinoid degeneration and Aschoff bodies in mitral valve leaflet histopathology and pericardial biopsy did not suggest rheumatic fever. The absence of caseating and noncaseating granulomas did not support tuberculous origin. Though the mycoplasma pneumonium antibodies were positive, no fungus was isolated from pericardial fluid after 21 days and pericardial specimen did not stain positive for fungus. Although the histology did not reveal the presence of spirochete in pericardial tissue, it was doubtful that the patient had viral endocarditis and postviral cardiomyopathy. Considering the possibilities of false seropositivity, the patient’s blood was sent to the state department of diagnostic immunology laboratory and it was confirmed positive for Lyme disease. Conceivably this is a very rare case of Lyme carditis involving the heart valve requiring surgical management. A high index of suspicion is required to make a diagnosis, especially for patients who may lack a suggestive history of tick exposure or residence in an endemic region [5]. The long-term follow-up would be helpful to study the further course of the Lyme heart valve disease in the future.
