Pulmonic valve endocarditis as an underdiagnosed disease: role of transesophageal echocardiography

Isolated Sub-Pulmonic Valve Endocarditis in a Patient With a History of Konno Procedure and Mechanical Aortic Valve

Pulmonic and sub-pulmonic valve endocarditis are rarely encountered in clinical practice. We present the first case of isolated sub-pulmonic endocarditis. A 30-year-old man with a history of mechanical aortic valve presented to the emergency department with multiple complaints including nausea, vomiting, body aches, and fevers. The patient underwent surgical resection for sub-aortic stenosis followed by a modified Konno procedure later in life. A modified basal short-axis view on the trans-thoracic echocardiogram revealed a sub-pulmonic mobile structure highly suggestive of infective endocarditis. Blood cultures grew methicillin-sensitive Staphylococcus aureus within 24 hours. Higher oxygen demand prompted chest imaging, chest CT showed the development of bilateral airspace consolidation, suggestive of pneumonia. After treatment with extended intravenous antibiotics, follow-up echocardiogram four months later showed no identifiable sub-pulmonic vegetation.

This case describes a situation where clinicians may suspect infective endocarditis in a typical location such as a mechanical aortic valve. However, in patients who develop pneumonia, infective endocarditis of the right heart should be suspected. The pulmonic valve and sub-pulmonic ridge are often difficult to image given their anatomical location, a modified basal short-axis view on trans-thoracic echocardiogram can better image these structures.

Pulmonary valve assessment by three-dimensional echocardiography

The pulmonary valve (PV) has historically been ignored by imaging studies. Disorders of the PV encountered in adult cardiac patients are increasingly encountered due to advanced care of patients with congenital heart disease and associated PV diseases. Despite advances in PV imaging, multiple challenges remain when it comes to obtaining high quality PV images. While 2D TTE is the usual initial imaging tool for PV, excellent views of the PV annulus and its one or two leaflets are obtained in less than half of patients. The 3D echocardiography en face view allows all three leaflets to be evaluated concurrently, as well as assessments of the RV outflow tract and main pulmonary artery, which has improved quantitative assessment of PV diseases. Increasing image quality and experience with live/real time 3D TEE amplifies its utility in accurate evaluation and helps guide and monitor successful percutaneous PV interventions. 2D TTE remains the first line diagnostic tool; however, 3D TTE and 3D TEE provide better image quality which increases diagnostic accuracy and guidance to therapy. In this review article, we stress improvement in 3D echocardiography and its role in diagnostic and therapeutic options for PV diseases.

Infective Endocarditis Involving the Pulmonary Valve

Pulmonary valve (PV) infective endocarditis (IE) is a rare entity, accounting for 1.5% to 2% of cases of IE. Published data are limited to a few case series and reports. We sought to review the Mayo Clinic experience and describe clinical, echocardiographic, and microbiologic features. We included all patients aged ≥18 years seen from 2000 to 2014 who had a diagnosis of native PV IE and unequivocal echocardiographic involvement of the PV. Nine patients with PV IE were identified. Isolated PV IE was present in 7 (78%) of 9 cases. The median age was 59 years and 22% were women. Three patients had congenital heart disease, 2 had central venous catheters, and 3 had cardiovascular implantable electronic devices. Five patients (56%) received chronic immunosuppressive therapy. Enterococcus faecalis and viridans group streptococci were the most common pathogens, isolated in 22% of cases each. Transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE) were done in 6 and 7 patients, respectively. Four patients underwent both procedures. TTE was diagnostic in all cases, but TEE failed to detect PV involvement in 1 patient. Median follow-up was 1.8 years. Five patients (56%) underwent PV replacement. There were no operative deaths. One patient had sudden death during follow-up, unrelated to his PV IE episode. Our results suggest that PV IE is rare but carries significant morbidity. TTE and TEE provide complementary information with TEE providing better visualization of other cardiac structures. Our findings of a high prevalence of immunosuppressive therapy and cardiovascular implantable electronic devices have not been previously reported and deserve further investigation.

Native valve right sided infective endocarditis

Right-sided infective endocarditis (RSIE) accounts for 5-10% of all cases of infective endocarditis (IE), and is predominantly encountered in the injecting drug user (IDU) population, where HIV and HCV coinfections often coexist. Staphylococcus aureus is the most common pathogen. The pathogenesis of RSIE is still not well understood. RSIE usually presents as a persistent fever with respiratory symptoms whilst signs of systemic embolisation as seen in left-sided IE are notably absent. The prompt diagnosis of RSIE thus requires a high index of suspicion. Transthoracic echocardiography (TTE) can detect the majority of RSIE, whilst transoesophageal echocardiography (TOE) can increase sensitivity. Virulence of the causative organism and vegetation size are the major determinants of prognosis. Most cases of RSIE resolve with appropriate antibiotic administration.

Use of echocardiography in the diagnosis and management of infective endocarditis

The first use of echocardiography in infective endocarditis (IE) was described in 1973. Since then, echocardiography has emerged as a major tool for the diagnosis and management of this disease. In general, transthoracic echocardiography (TTE) is adequate for diagnosing IE in cases where cardiac structures-of-interest are well visualized. Specific situations where transesophageal echocardiography is preferred over TTE include the presence of a prosthetic device, suspected periannular complications, children with complex congenital cardiac lesions, selected patients with Staphylococcus aureus bacteremia, and certain pre-existing valvular abnormalities that make TTE interpretation problematic (eg, calcific aortic stenosis). Echocardiography is also useful for risk stratification. Evidence suggests that vegetation size can predict embolic complications, although the data are inconsistent. Careful clinical assessment is essential to the proper use of echocardiography in diagnosing IE, visualizing complications related to IE, and evaluating candidacy for surgical intervention.

Pulmonary homograft endocarditis after ross procedure

We report the case of a 36-year-old patient who experienced an isolated acute pulmonary homograft endocarditis two years after a Ross procedure for aortic valve infective endocarditis.

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.

[Isolated pulmonary endocarditis on native valve in elderly patient without predisposing factors]

Isolated infective endocarditis in the native pulmonary valve is an unusual clinical entity in patients without predisposing factors and in non-intravenous drugs users. We present the case of a 75-year-old patient, with a subacute clinical picture of fever and pulmonary cavity nodules, admitted to our hospital with an initial suspected diagnosis of pulmonary tuberculosis. The presence of Enterococcal bacteremia in hemocultive and the documentation of a large vegetation in pulmonary valve by transtoracic and transesophageal echocardiography were key factors for final diagnosis.

Transesophageal echocardiography

This article presents an overview of the benefits and efficacy of transesophageal echocardiography (TEE) in the critically ill patient. The echocardiographic evaluation of ventricular function both regional and global, is discussed with special emphasis on ischemic heart disease; assessment of preload, interrogation of valvular heart disease (prosthetic and native) and its complications; endocarditis and its complications; intracardiac and extracardiac masses, including pulmonary embolism; aortic diseases (e.g., aneurysan, dissection, and traumatic tears); evaluation of patent foramen ovale and its association with central and peripheral embolic events; advancements in computer technology; and finally, the effect of TEE on critical care.

Role of transthoracic and transesophageal echocardiography in diagnosis and management of infective endocarditis

Echocardiography has become a mainstay in the diagnosis of endocarditis. Vegetations were first visualized noninvasively beginning with M-mode echocardiography in the mid-1970s. The evolution of echocardiography, to include first two-dimensional imaging and then Doppler imaging in the 1980s, established echocardiography as the noninvasive test of choice to evaluate for the presence of vegetations as well as for their sequelae. Most recently, the addition of transesophageal echocardiography has expanded the role and yield of echocardiography in diagnosing endocarditis as well as in guiding management.

Assessment of endocarditis and associated complications with transesophageal echocardiography

TEE offers many benefits in the evaluation of patients with IE. It provides increased sensitivity as compared to TTE in the detection of this disease, and is better able to identify and delineate many of the associated complications and hemodynamic aberrancies. TEE also has helped expand our knowledge of the pathophysiology and natural history of IE. Continued advances in the technology of TEE instrumentation undoubtedly will lead to further improvements in our ability to assess and to treat patients stricken with this serious infection. Nevertheless, IE continues to exact a significant toll on its victims, and our efforts to diagnose, to treat, and to prevent it must not weaken.

Role of transesophageal echocardiography in right-sided endocarditis

Investigations performed over the last few years support the invaluable usefulness of transesophageal echocardiography in the diagnosis of left-sided endocarditis. Whether this can be applied to right-sided endocarditis remains speculative. Patients at risk of having right-sided endocarditis can be classified into three different and well-defined groups: (1) intravenous drug abusers; (2) patients with pacemakers; and (3) patients with congenital heart diseases. In this article, we review the different value of transesophageal echocardiography in right-sided endocarditis depending on the subset of patients considered.

Has transesophageal echocardiography changed the approach to patients with suspected or known infective endocarditis?

Infective endocarditis is still a great clinical challenge. Its diagnosis is difficult to establish, and mortality has remained around 30%. Early diagnosis and optimal treatment are crucial fo prognosis improvement. Echocardiography plays an indispensable role in the management of this disease, especially with the recently introduced approach, transesophageal echocardiography (TEE). TEE can overcome the limitations of transthoracic echocardiography (TTE) and is superior to TTE in almost every way in providing earlier and more information for the diagnosis and treatment of infective endocarditis. TEE detects valve vegetations with much higher sensitivity and specificity than TTE. It can demonstrate smaller vegetations in the early stage of the disease and vegetations on atypical locations (e.g., mitral valve annulus), and provides detailed characterization of vegetations (e.g., location, size, mobility, and changes during treatment). Such information is of great prognostic value and may help in selecting proper treatment. TEE is more sensitive for detecting complications, such as mitral valve perforation, abscess, and subaortic complications, which respond poorly to medicine and for which timely surgery may be the best treatment. For those with prosthetic valve endocarditis, TEE is especially useful because TTE is greatly limited by the acoustic shadow of prostheses. Both positive and negative results of TEE examination are valuable for confirming or excluding infective endocarditis. TEE also plays a unique role in intraoperative monitoring and can assess surgical results before the chest is closed. TEE has become an invaluable tool for the diagnosis and management of patients with suspected or known infective endocarditis.

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

A 48 year old patient with resistant coeliac disease developed prolonged unexplained pyrexia after surgery for small bowel volvulus. Despite extensive investigations and intensive antibiotic therapy, he deteriorated and died eight weeks postoperatively and significant isolated pulmonary valve endocarditis was discovered at autopsy. This diagnosis should be considered in all critically ill patients with unexplained pyrexia even in the absence of clinical features of endocarditis and transoesophageal echocardiography performed to exclude or confirm this lesion.

Application of transthoracic and transesophageal echocardiography in the diagnosis and management of infective endocarditis

Infective endocarditis continues to be a cause of significant cardiac morbidity and mortality. To improve the prognosis of patients with this disorder, early diagnosis is crucial but difficult to establish on the basis of clinical parameters alone. Echocardiography, both transthoracic and transesophageal techniques, has a major role in the detection of vegetations that are the hallmark of endocarditis. Valvular and perivalvular complications can also be well assessed by echocardiography. With the improved resolution provided by recent technologic advances in echocardiography, vegetations can be reliably detected in most patients with endocarditis. We propose that present diagnostic criteria for endocarditis be revised to include echocardiographic findings as a major parameter in the diagnosis. Finally, a diagnostic approach incorporating transthoracic and transesophageal echocardiography in these patients will be discussed taking into consideration the different degrees of clinical suspicion for the existence of the disease.

Transesophageal echocardiography in diagnosis of infective endocarditis

STUDY OBJECTIVE

To determine whether transesophageal echocardiography (TEE) was superior to transthoracic echocardiography (TTE) in defining valvular vegetations and diagnosing clinical infective endocarditis (IE) in patients suspected of having this infection.

PATIENTS AND METHODS

Between April 1989 and May 1991, 64 febrile patients with clinical and/or microbiologic risk factors for IE were prospectively enrolled. Patients underwent both TEE and TTE, which were interpreted in a blinded fashion as to the patient's clinical status. Clinical criteria for the diagnosis of IE were compared with TEE and TTE findings to delineate the ability of the two echocardiographic techniques to define valvular vegetations and to establish the clinical diagnosis of vegetative IE.

RESULTS

Thirty-four valves had typical valvular vegetations demonstrated by either TEE or TTE. Transesophageal echocardiography was more sensitive than TTE in identifying valvular vegetations (33/34 vs 23/34 instances, respectively; p = 0.004). Also, TEE was better at identifying smaller vegetations (< 1 cm) than TTE; 12 patients with such vegetations were identified by TEE as compared with only 5 of 12 identified by TTE (p = 0.02). Of the 64 patients enrolled, 30 (47 percent) were classified as having "definite" or "probable" IE by modified von Reyn criteria. Among these 30 patients, TEE was significantly more sensitive than TTE at documenting vegetative valvular lesions (26/30 [87 percent] vs 18/30 [60 percent], respectively) (p < 0.01). Both TEE and TTE were highly specific (91 percent) in delineating valvular vegetations in this patient population; two of the three false-positive TEE studies for valvular vegetations occurred in patients with a history of IE. All nine periannular complications of IE were identified by TEE, as compared with only two being defined by TTE (p = 0.001).

CONCLUSIONS

Transesophageal echocardiography is significantly more sensitive than TTE and highly specific in both confirming the clinical diagnosis of IE, as well as in identifying valvular vegetations in patients at risk for this infection. Our data also support the concept that TEE is the echocardiographic method of choice for defining small vegetations and periannular complications in IE.

Echocardiographic evaluation of isolated pulmonary valve disease in adolescents and adults

Congenital pulmonary valve disease is often not discovered until adolescence or adulthood. Transthoracic two-dimensional echocardiography can provide detailed information regarding right ventricular outflow anatomy, although images are often less satisfactory than those obtained in infants and children. The more recent addition of biplanar transesophageal echocardiography has enhanced our ability to image the right ventricular outflow tract, pulmonary valve, and pulmonary artery noninvasively. Pulsed and continuous-wave Doppler estimates of subvalvular and transvalvular gradients have proved to be accurate. Doppler color flow mapping has proved useful in determining the location and direction of stenotic and regurgitant flow. With no accepted standard for comparison, quantification of regurgitation remains problematic. In many cases, echocardiography has replaced catheterization and angiography in the evaluation and long-term follow-up of congenital pulmonary valve disease before and after intervention.