Isolated pulmonary valve endocarditis: a rare or an underdiagnosed disease?

Cardiopulmonary manifestations of isolated pulmonary valve infective endocarditis demonstrated with cardiac CT

Right-sided infective endocarditis involving the pulmonary valve is rare. This pictorial essay discusses the use and findings of cardiac CT combined with delayed chest CT and noncontrast chest CT of pulmonary valve endocarditis. Cardiac CT is able to show the full spectrum of right-sided endocarditis cardiopulmonary features including manifestations that cannot be demonstrated by echocardiography.

Isolated infective endocarditis of the pulmonary valve: an autopsy analysis of nine cases

INTRODUCTION

Infective endocarditis (IE) of the pulmonary valve is uncommon and usually occurs in conjunction with tricuspid and/or left-sided valvular endocarditis. There have been only sporadic reports of isolated pulmonary valvular infective endocarditis (PVIE). This report documents the pathological features of nine such cases at autopsy.

METHODS

Among 155 cases of IE encountered in a 14-year period, we selected nine cases that had isolated PVIE for analysis. The clinical records were reviewed for the patient demographics, presence or absence of underlying cardiac disease or other predisposing factors, and modes of presentation; these were correlated with the relevant investigations. A detailed study of the heart was done in all with special attention to the pulmonary valve morphology.

RESULTS

The nine cases of isolated PVIE formed 5.8% of the IE cases, seen in six males and three females, largely adults. Seven patients (77.8%) had admissions for about 24 h. Hospital admission was sought for mainly progressive shortness of breath (66.7%) and fever (44.4%). Congenital heart disease was seen in seven (77.8%); two (an infant and an adult) had normal hearts. A single blood sample for blood culture in two patients was negative. Two-dimensional echocardiography, performed in eight, revealed vegetations on the pulmonary valve in four. The pulmonary valve was tricuspid in six cases, bicuspid in two, and unicuspid in one. The vegetations (active in three, active and healing in two, healed in four) were accompanied by concomitant thickening, shortening, perforations, or complete destruction of the cusps. Involvement of the right ventricular outflow tract or the main pulmonary artery was identified in five hearts. Five patients (55.6%) developed pulmonary complications, related to the endocarditis.

CONCLUSIONS

Detection of PVIE, especially the isolated type, may be underdiagnosed. This condition should be kept in mind during evaluation of patients especially with cardiac anomalies, who present with fever, prominent respiratory symptoms, and negative blood cultures.

Pulmonic valve endocarditis

Pulmonic valve endocarditis is an extremely rare infection that shares epidemiologic, clinical, radiologic, microbiologic, and prognostic features with tricuspid valve endocarditis. We report a case of pulmonic valve infection on a structurally normal heart and review the English-language literature on this subject.

Isolated pulmonic valve endocarditis caused by group B streprococcus (Streptococcus agalactiae)--a case report and literature review

The pulmonic valve is the least commonly involved valve in infective endocarditis. Pulmonic valve endocarditis is usually associated with tricuspid valve endocarditis, and isolated pulmonic valve endocarditis is exceedingly rare. The predisposing factors for developing pulmonic valve endocarditis include a congenitally anomalous pulmonic valve, intravenous drug abuse, and the presence of indwelling intravenous or flow-directed pulmonary artery catheters. More cases of group B streptococcus endocarditis are being reported. The risk factors for group B streptococcus endocarditis include diabetes mellitus, cancer, alcoholism, malnutrition, immunocompromised status, intravenous drug abuse, postpartum and postabortion states, and underlying valvular disease. The vegetations of this type of endocarditis are usually large and have a higher tendency to result in embolism. The presentation of group B streptococcus endocarditis is usually acute and may result in rapid valve destruction if not treated promptly. A case of isolated pulmonic valve endocarditis caused by group B streptococcus, Streptococcus agalactiae, is presented that was diagnosed with multiplane transesophageal echocardiography in a 40-year old, alcoholic, malnourished man, who was successfully treated with intravenous penicillin G. The literature on the isolated pulmonic valve endocarditis caused by group B streptococcus is reviewed.