Double-Valve Libman-Sacks Endocarditis Causing Ventricular Fibrillation Cardiac Arrest

Abstract

Libman-Sacks endocarditis is a well-known and rather common cardiac manifestation of systemic lupus erythematosus. Transesophageal and transthoracic echocardiography are the definitive imaging methods used to evaluate cardiac valvular involvement in this disease. Valvular masses (vegetations) and valvular thickening are 2 common morphologic echocardiographic patterns. Libman-Sacks lesions are typically characterized by single-valve involvement and their small size of 1 to 4 mm.

Herein, we present the unusual case of a 22-year-old woman with newly diagnosed systemic lupus erythematosus who had large, sterile vegetations of Libman-Sacks endocarditis that involved the mitral and aortic valves. This compromised coronary blood flow and resulted in ventricular fibrillation cardiac arrest. The vegetations were surgically excised, and the patient's cardiac function recovered. We discuss the treatment of the patient and that of Libman-Sacks endocarditis.

Libman-Sacks (LS) endocarditis, a well-known cardiac manifestation of systemic lupus erythematosus (SLE), commonly presents with embolic phenomena or valvular dysfunction. Herein, we describe the case of a young woman with newly diagnosed SLE who developed ventricular fibrillation (VF) cardiac arrest caused by LS endocarditis.

Case Report

In June 2009, a 22-year-old woman presented with acute-onset unresponsiveness and tonic-clonic seizures after experiencing recurrent chest pain for several days. Her medical history included SLE, which had been diagnosed 2 weeks earlier, along with symptoms of arthritis. Therapy included hydroxychloroquine and prednisone. She had experienced several syncopal episodes of unclear cause during the past few years.

Upon arrival at the emergency department, she was unresponsive and cyanotic. Subsequent VF cardiac arrest necessitated cardiopulmonary resuscitation. After her pulse was restored, an electrocardiogram revealed sinus tachycardia with normal ventricular conduction. A computed tomogram of the brain disclosed nothing unusual. Transthoracic echocardiography showed normal left ventricular function and size, mild mitral and tricuspid regurgitation, and 2 intracardiac masses. The first, above a trileaflet aortic valve, was an ill-defined mass (size, 1.5–2 cm) that occupied the noncoronary cusp and obliterated almost half of the ascending aortic lumen. The second was a sessile lesion (size, <1 cm) on the anterior mitral leaflet. These results were confirmed by use of transesophageal echocardiography (Figs. 1, 2, and 3).

Fig. 1 Transesophageal echocardiogram (apical short-axis view) of the aortic valve shows a large mass within the noncoronary cusp.

Fig. 2 Transesophageal echocardiogram (long-axis view) of the aortic valve reveals a mass that extends cephalad into the ascending aorta and obliterates almost half of the ascending aortic lumen.

Fig. 3 Transesophageal echocardiogram (apical 4-chamber view) shows a small mass on the anterior leaflet of the mitral valve, on the left atrial side.

The patient underwent emergent surgery. Two friable lesions were resected: a 1.3 × 0.8 × 0.5-cm mass on the anterior mitral valve leaflet, and a 2.8 × 2.4 × 0.4-cm mass, attached to the base of the noncoronary cusp and floating within the aorta. The intact valves and chordae tendineae required neither repair nor replacement. Histopathologic analysis of both masses revealed organizing fibrin thrombus and granulation tissue, consistent with vegetations (Fig. 4). The surgical tissue cultures and several blood cultures were negative for infection. Results of immunologic, autoantibody, and hypercoagulability studies were consistent with SLE without evidence of antiphospholipid syndrome or hypercoagulable state.

Fig. 4 Low-power photomicrographs show organizing fibrinous exudate and thrombus with granulation tissue. A) H & E, orig. ×4; B) H & E, orig. ×10.

Postoperatively, the patient had weakness of the left upper extremity. Computed tomography of the brain revealed a new multifocal acute-to-subacute infarction. The diagnosis was embolic stroke and LS endocarditis with aortic and mitral valve vegetations as a manifestation of SLE. Therapy with systemic steroids, hydroxychloroquine, aspirin, and warfarin was initiated. The patient was discharged from the hospital after 3 weeks and was continued on the medical regimen. Nearly 2 years after surgery, she had no recurrent arrhythmias or clinical features of valvular dysfunction.

Discussion

The pathogenesis of LS endocarditis is thought to involve immunoglobulin and complement deposition and the formation of fibrin-platelet thrombi on the affected valve. The organization of these thrombi leads to valvular fibrosis, distortion, and eventual dysfunction.¹ The prevalence of LS endocarditis in patients with SLE is 10% in clinical studies^1–3 and ranges from 35% to 65% in autopsy studies.^4,5

We observed 2 morphologic echocardiographic patterns in our patient: valvular masses (vegetations) and valvular thickening. These conditions can coexist, and either can be associated with valvular dysfunction, particularly with regurgitation. Libman-Sacks lesions are typically sessile, wartlike, and small, varying in size from 1 to 4 mm.⁶ They develop more frequently on the left-sided valves, chiefly on the mitral valve.⁶ The diagnosis in our patient, double-valve LS endocarditis, is rarely reported. In previous cases, the patients had aortic and mitral valve involvement that required valve replacement.⁷

Patients with SLE and LS endocarditis are typically asymptomatic unless the lesions progress to more severe valvular dysfunction or to embolic events. We believe that our report is the first of a patient who developed VF cardiac arrest that was caused by LS endocarditis. We speculate that the friable aortic vegetation led either to intermittent obstruction of the right coronary artery cusp or to embolization to the coronary artery, resulting in compromised coronary blood flow and the induction of VF.

Little in the medical literature is devoted to the treatment of LS endocarditis. The aggressive treatment of associated diseases, such as SLE and antiphospholipid syndrome, is warranted. Therapy with corticosteroids has been associated with smaller, fewer, and univalvular vegetations; however, there is no evidence that it can prevent valvular damage.^6,8 In patients who require valve replacement, mechanical prostheses are usually implanted out of concern for possibly recurrent disease and the early degeneration of bioprosthetic valves. Antithrombotic therapy, including antiplatelet agents, vitamin K antagonists, and heparin, is certainly indicated as secondary prevention in patients who have already experienced an embolic event.