Primary Mural Endocarditis Without Valvular Involvement

Abstract

Primary mural endocarditis is an extremely rare infection in which nonvalvular endocardial involvement is seen without any cardiac structural abnormalities such as ventricular septal defects. The rapid and precise diagnosis of this disease remains challenging. We present 2 cases (67- and 47-year-old male patients) of pathologically confirmed primary mural endocarditis that could have been detected by initial transthoracic echocardiography in the emergency department. Transthoracic echocardiography and transesophageal echocardiography play critical roles in the early recognition and confirmation of primary mural endocarditis.

Primary Mural Endocarditis Caused by Streptococcus pyogenes

“…Previous cases have reported failure of antimicrobial therapy alone in resolution of mural endocarditis. 2 In our case, however, the patient was successfully treated using conservative methods given no evidence for serious complications, and there was clinical improvement and resolution of vegetations with antimicrobial therapy. Annular thickening was presumably related to endocardial or myocardial inflammation in this case and remained unchanged.…”

“…1,7,8 The most common causative organisms of mural endocarditis include S aureus, Streptococcus species, Candida species, and Aspergillus species. 2 Our patient is the second reported case of primary mural endocarditis caused by group A beta hemolytic Streptococcus bacteremia; the first involved a 3-year-old girl with a history of developmental delay and Chiari malformation in 1992. 9 S pyogenes is an overall rare cause of infective endocarditis in any age group.…”

“…1 Risk factors for mural endocarditis otherwise include immunosuppression, intravenous drug abuse, prior cardiac surgery, and chronic debilitating disease. 2 The clinical presentation of mural endocarditis is otherwise similar to that of infective valvular endocarditis. 3 Mural endocarditis is most commonly caused by Staphylococcus aureus and Streptococcus species, but any endocarditis caused by group A beta hemolytic Streptococcus is uncommon.…”

The use of cardiac MRI in a rare case of primary mural endocarditis

“…Non-valvular endocardial infections are often secondary to valvular vegetations, regurgitation, prosthetic valves and congenital shunts; however, primary mural endocarditis occurs without any cardiac structural abnormalities 1 2. Tahara et al performed a Medline literature search and reported only 19 cases of primary mural endocarditis since 1986 2. Transthoracic and transoesophageal echocardiograms remain the standard of care for prompt diagnosis of this disease process 2.…”

“…Tahara et al performed a Medline literature search and reported only 19 cases of primary mural endocarditis since 1986 2. Transthoracic and transoesophageal echocardiograms remain the standard of care for prompt diagnosis of this disease process 2. Yet, patients commonly opt against transoesophageal echocardiogram due to invasive approach or sedation requirements.…”