Right Ventricular Mural Bacterial Endocarditis

Abstract

A 40-year-old man who was a smoker with no history of intravenous drug use presented to a tertiary hospital with a week-long high-grade fever, dry cough, and streaky hemoptysis. He had hypoxia at room air. Chest x-ray showed bilateral ground-glass opacities with relative sparing of apexes and left base (Figure 1).Sputum and blood cultures (including fungal) and HIV tests were negative. He had received intravenous piperacillin and tazobactam empirically for a week, with fair clinical improvement and resolution of radiological shadows. He was referred to our tertiary center for further management. Ocular fundi had multiple preretinal hemorrhages, a few with central clearing (Figure 2).Transthoracic echocardiogram revealed a bilobed, oscillating, 2ϫ1.5-cm right ventricular mass with peduncle arising from the anterior end of the moderator band ( Figure 3A and Movie I of the online Data Supplement).Transesophageal echocardiogram ( Figure 3B and Movie II) showed a 2-mm patent foramen ovule, and all valves were normal. The mass was visualized in a modified 4-chamber midesophageal view. Sixty-four-slice computed tomography pulmonary angiography showed no filling defects in the pulmonary artery. Cardiac magnetic resonance imaging (Figure 4 and Movie III) showed the contrast-nonenhancing mass and confirmed a structurally normal heart. His blood cultures were negative even after prolonged culture. He was started on empirical endocarditic therapy with vancomycin and gentamicin on suspicion of the mass being infective vegetation. Because the fever continued beyond a week of antibiotics, the decision to remove the mass was made.He underwent right atriotomy under cardiopulmonary bypass. The right ventricle and tricuspid valve were normal. A linear 2ϫ0.5-cm pale white growth and a smaller 0.5ϫ0.5-cm pale gray growth that were loosely attached to the moderator band were noted and removed. Right ventricular endothelium was normal throughout, and excision of the moderator band was not done.Histopathological examination showed fibrinous material with predominantly neutrophilic infiltrates ( Figure 5) and Gram-positive cocci (Figure 6). Culture of specimen yielded Staphylococcus aureus sensitive to methicillin and gentamicin. Hence, oxacillin and gentamicin were continued for another 2 weeks. The patient became afebrile, and C-reactive protein values were normalized. He was doing well at the 1-year follow-up visit.

Morphogenetic aspects of the septomarginal trabecula in the human heart

“…A few reports confirm the occurrence of additional conductive ways within the septomarginal trabecula, being a morphological substrate of Mahaim tachycardia [31]. Other implications of the described structure are also present in the literature: it may cause misdiagnoses during visual examinations [32, 33] or constitute a site for a clot or bacterial vegetation [32, 34]. …”

Case report on right ventricular mural endocarditis, not diagnosed clinically, but histopathologically after cardiac surgery

“…16 , 17 RVME as a definitive diagnosis was determined after two open-heart surgeries that confirmed anchored vegetations. 11 , 18 At 5-year FU, he was asymptomatic and enjoyed a normal life.…”

“…Isolated RVME is an unusual type of IE, 4 , 5 occurring in association with predisposing factors but also in previously healthy individuals as this patient. 10 A hypothetical mechanism refers to the RV moderator band where trabeculations could act as a nidus for infection, 11 similar as the location for vegetations in this case. Endocarditis was not considered in the absence of risk factors and unremarkable cardiac examination.…”

Comprehensive Echocardiographic Evaluation of an Atypical Left Ventricular Mass with an Unusual Site of Attachment

“… 2 The exact incidence of mural endocarditis is not clear. Mural vegetations have been reported to occur in left ventricular aneurysms, 3 the right ventricular moderator band, 4 and the right atrium. 5 Several lines of evidence support the notion that the patient may have had an atypical presentation of partially treated mural endocarditis.…”

“… 6 Koshy et al . 4 described a 2.0 × 1.5 cm vegetation over the right ventricular moderator band, diagnosed on TTE and TEE. Lo et al .…”