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Infectious lesions mimicking cardiac masses


Key points

  • Vegetations are oscillating or nonoscillating intracardiac masses on the valves or other endocardial structures or intracardiac implanted materials.

  • Vegetations are typically located on the upstream side of the valves, are usually irregularly and grotesquely shaped, and exhibit disordered motions that are not in pattern with the excursion of the valve leaflets.

  • Abscesses are thick, nonhomogeneous, echolucent, or echodense perivalvular areas.

  • Three echocardiographic findings are considered to be major criteria for the diagnosis of endocarditis: (1) the presence of vegetations, (2) the presence of abscesses, and (3) the presence of new dehiscence in a valvular prosthesis ( Algorithm 7.1 , Figs. 7.2–7.4 , Tables 7.5 and 7.6 , Figs. 7.7–7.9 , Table 7.10 ).

    Algorithm 7.1, The image depicts the approach to IE [1] . IE , infective endocarditis; TTE , transthoracic echocardiography; TEE , transesophageal echocardiography.

    Fig. 7.2, Transesophageal echocardiography in a patient with mitral valve endocarditis shows a large, mobile, shaggy, bizarre-shaped mass on the anterior mitral valve leaflet (A and B), which has resulted in the malapposition of the leaflets and a severe, eccentric-jet, posterolaterally directed mitral regurgitation (C). A 3D zoom reconstruction of the mitral valve mass is depicted in section (D, black arrow ). The mass characteristics and clinical findings are compatible with infective endocarditis, as documented by Staphylococcus aureus growth in postsurgical specimen growth.

    Fig. 7.3, The image illustrates the transesophageal echocardiographic examination of a patient with a bicuspid aortic valve (mediolateral orientation). There is a shaggy, semimobile echodensity attached to the tip of the medial leaflet (B, white arrow ). The valve is destructed with the perforation and flail of the lateral leaflet (C, white arrow ).

    Fig. 7.4, Transesophageal echocardiography in a patient with aortic bioprosthesis shows a large, semimobile, oval-shaped echodensity on the right cusp of the aortic bioprosthesis (white arrows) . The postsurgical specimen confirmed fungal endocarditis with Candida albicans [2] .

    Table 7.5
    Risk factors for fungal endocarditis.
    Risk factors for fungal endocarditis
    Intravenous drug abuse
    Prolonged antibiotic therapy
    Prolonged indwelling central venous catheter
    Prosthetic heart valve
    Previous history of endocarditis
    Parenteral nutrition
    Neutropenia
    Diabetes mellitus

    Table 7.6
    Clinical significance of fungal endocarditis.
    Clinical significance of fungal endocarditis
    Fungal endocarditis is a very devastating disease
    Timely diagnosis is the key, because it presents mostly with general constitutional symptoms; high index of suspicion is required for early diagnosis. Induction treatment followed by suppressive therapy (in selected patients) is key to management
    Surgical replacement of the infected valve is a class I recommendation

    Fig. 7.7, Transthoracic echocardiography in the parasternal long-axis view shows a large, hypermobile, oval-shaped, hyper echo mass attached to the atrial side of the base of the anterior mitral valve leaflet, which protrudes into the left ventricle in the diastole. The mass is a large fungal vegetation in an intravenous drug abuser presenting with fever and malaise. The mass has a high probability for endocarditis complications, including valve destruction, mitral stenosis, regurgitation, abscess formation, and systemic embolism ( Supplementary Video 7.S1 ). Fungi account for fewer than 10% of infective endocarditis cases, with native valve fungal endocarditis being even less common. Approximately, 24% of fungal endocarditis cases are caused by Candida albicans . It is usually seen in patients with valvular disease, intravenous drug use, indwelling vascular lines, or immunocompromised states. Echocardiography cannot distinguish fungal vegetations from other microorganisms definitely; nevertheless, a dense, hyperechoic, large mass (≈ 2 cm) in the relevant clinical setting can be in favor of a fungal vegetation. Overall, patients with fungal endocarditis have a poor prognosis, and left-sided fungal endocarditis, acute heart failure, and exclusive medical treatment are independent risk factors for mortality [3] .

    Fig. 7.8, The figures reveal tricuspid valve infective endocarditis in transthoracic echocardiography. (A) Echocardiography in the apical 4-chamber view in a 38-year-old woman on hemodialysis presenting with prolonged fever shows a shaggy, mobile vegetation on the tricuspid valve oscillating between the right ventricle and the right atrium. (B) Echocardiography in the parasternal short-axis view in a young intravenous drug abuser reveals tricuspid valve vegetations. The differential diagnosis of these vegetations is the tricuspid valve tumor.

    Fig. 7.9, Transesophageal echocardiography in 2 patients with hydatid cysts. There is a large, round-shaped cystic mass, with an echolucent center attached to the base of the left ventricular lateral wall (B and C, black arrows ). This mass is accompanied by a similar lesion in the liver (A, white arrow ), which suggests cardiac and hepatic hydatid cysts. A large, globular cystic lesion with a central opacity is seen attached to the left ventricular apicoseptal segment, in favor of a hydatid cyst with a daughter cyst within it. Cardiac hydatid cysts are uncommon, with the dominant involvement of the left ventricle. The cysts may grow and lead to compression effects on the adjacent myocardium, resulting in coronary vessel involvement, rhythm disturbances, and interference with valvular and ventricular function. Echocardiography is the method of choice for the assessment of cardiac hydatidosis [4] .

    Table 7.10
    Localization of cardiac hydatid cysts (%).
    Localization of cardiac hydatid cysts (%)
    Left ventricle 60
    Right ventricle 10
    Pericardium 7
    Left atrium 6–8
    Right atrium 3–4
    Interventricular septum 4

  • Any component of the heart is vulnerable to be involved by hydatid cysts, with the presentation depending on the location, size, and integrity of the cyst ( Figs. 7.11–7.18 , Tables 7.19–7.21 ).

    Fig. 7.11, The images demonstrate hydatid cysts in the upper interventricular septum. Transthoracic echocardiography in a patient with a hydatid cyst in the upper interventricular septum. There is a large, round-shaped cystic mass, with an echolucent center attached to the base of the interventricular septum (white arrows) . The initial manifestation of this patient was a complete heart block, which is one of the rare complications of the interventricular septum hydatid cyst. Echocardiography is a preferred and effective modality for the diagnosis of cardiac hydatidosis. This modality shows the cysts, their locations in the interventricular septum, their number, and their size, as well as the hemodynamic compromise and eventual complications such as pericardial effusion. The coronary circulation is the main pathway by which the parasitic larvae reach the heart. Cardiac involvement through the pulmonary veins has also been reported. Due to the rich coronary blood supply, the left ventricular wall is the most common cardiac location (60%), followed by the right ventricle (10%), the pericardium (7%), the left atrium (6%–8%), and the right atrium (3%–4%). The interventricular septum is less frequently involved. It is reported in just 4% of cardiac cases [5] .

    Fig. 7.12, The images depict a large left atrial hydatid cyst visualized by transesophageal echocardiography (109°) in a 61-year-old male traveler presenting with chest pain and dyspnea on exertion. (A) Studies in 2D and 3D reveal a large, round, spongy mass in the left atrium consisting of multiple echolucent, round components. The feature is typical of a large hydatid cyst, confirmed by pathology. (B) Diastolic turbulence over the mitral valve is indicative of the compressive effect of the mass, resulting in functional mitral stenosis, the most probable reason for the patient’s symptoms ( Supplementary Video 7.S2 ).

    Fig. 7.13, The images present a hydatid cyst in the right ventricle. Transesophageal echocardiography shows a large cystic mass in the right ventricle in a 51-year-old woman presenting with dyspnea. The mass measures 3.1 cm × 3.2 cm in size and is located adjacent to the tricuspid valve. It protrudes into the right ventricle in the diastole, resulting in tricuspid regurgitation and moderate pulmonary hypertension. The feature of the mass is suggestive of cardiac hydatidosis (confirmed by pathology).

    Fig. 7.14, The images depict a hydatid cyst in the right ventricle (A, B, and C). The apical long-axis and apical short-axis views of transthoracic echocardiography in a patient show a solitary, round, echolucent cystic mass in the right ventricular apex, suggestive of a hydatid cyst. The mass measures 1.2 cm × 1.3 cm in size. (D) Thoracic computed tomography scan confirms the cystic mass of the right ventricular apex. (E) The interrogation of the liver shows an associated finding: a large, hepatic hydatid cyst, which is a supporting finding for the cardiac finding of a hydatid cyst. (F) The most common sites of hydatid cysts are the liver (50%–70%), lungs (5%–30%), muscles (5%), bones (3%), kidneys (2%), spleen (1%), and brain (1%). Cardiac echinococcosis is an uncommon disease, with an estimated prevalence ranging from 0.5% to 2% [5] . Two-dimensional echocardiography is the first-line test of choice to make the diagnosis of a cardiac hydatid cyst, with greater than 90% sensitivity. It is a quick, highly sensitive, noninvasive imaging modality that can demonstrate the presence of cardiac masses and characterize cysts using ultrasound. The use of an ultrasound-enhancing agent may be helpful to clearly delineate the location and size of the mass. Furthermore, it can determine whether the cyst is enclosed or ruptured, whether it is communicating with the blood supply within the heart, and whether it is vascularized. Patients with exposure to or the presence of echinococcosis in any part of the body should undergo assessment using echocardiography of their heart and major vessels [6] .

    Fig. 7.15, A 21-year-old female with a bilobed cystic lesion in left ventricular cavity (A). Unenhanced CT (B) depicts the partial faint calcification of the cyst wall, characteristic for hydatid cyst. Abdominal (C and D) and brain CT scan reveal other lesion (arrows) with the same feature scattered in liver and subcutaneous temporal fossa.

    Fig. 7.16, A 42-year-old female for whom echocardiography (A) reported a round interventricular septum mass with peripheral echogenic wall bulging toward the right ventricular cavity suggestive of a hydatid cyst. Steady-state free precession (SSFP) sequence of the CMR demonstrates the well-defined somewhat thick-wall cystic lesion with homogeneous internal material which show high T1-weighted (D) and STIR (E) intensity likely due to the high proteinaceous content. The ring-like reactive capsular peripheral of the lesion in late gadolinium enhancement (LGE) sequence (F) is compatible with the diagnosis of hydatid cyst.

    Fig. 7.17, The image presents permanent pacemaker-associated infective endocarditis. (A) Transthoracic echocardiography in the apical 4-chamber view in a patient with a history of permanent pacemaker implantation presenting with long-standing fever after COVID-19 infection shows a round, heterogeneous mass attached to the right ventricular lead of the permanent pacemaker. Given the patient’s history, the echocardiographic finding is mostly a large vegetation, but thrombosis is the differential diagnosis. (B) A schematic figure of the vegetations on the right ventricular and right atrial leads is presented herein. Transesophageal echocardiography is most often required to detect lead vegetations. Mostly, local pocket infections have smaller vegetations, whereas larger vegetations are more commonly associated with the signs of systemic illness. The guidelines of the American Heart Association and the Heart Rhythm Society recommend complete device removal with a prolonged course of antibiotics in any patient with cardiac implantable electronic device infection. Lead removal can be accomplished in most cases via percutaneous techniques. Clinically significant pulmonary emboli secondary to percutaneous extraction are rare. This is even true for patients with large vegetations seen on echocardiography. An open surgical approach is usually reserved for patients with concomitant valvular endocarditis or extremely large vegetations (generally > 3 cm) [7 8] .

    Fig. 7.18, The images illustrate abscess formation in tricuspid valve endocarditis. (A) The transthoracic echocardiographic examination of a patient presenting with fever, fatigue, and weight loss shows severe dilation in the right ventricle and the right atrium, together with a round cystic mass at the atrial side of the base of the septal leaflet of the tricuspid valve. The left and right panels show the mass in the systole and the diastole, respectively. (B) Color Doppler study shows fistulization in the cystic mass into the right ventricular outflow tract. Considering the patient’s clinical status and laboratory findings, the diagnosis is complicated infective endocarditis, a tricuspid valve abscess with a fistula into the right ventricular outflow tract, and septic pulmonary embolism, resulting in the hemodynamic compromise of the right heart. The tricuspid valve is involved in 90% of right-sided infective endocarditis cases mostly related to intravenous drug use. The frequency of specific complications depends on variables such as the infecting pathogen, the duration of the disease before therapy, and the type of treatment. Congestive heart failure is the most important complication of infective endocarditis, and it has the greatest impact on the prognosis. Periannular abscesses are a relatively common complication of infective endocarditis (42%–85% of cases during surgery or at autopsy, respectively), associated with higher morbidity and mortality. Patients who develop abscesses are more likely to undergo surgery than those who do not (84%–91% vs 36%), and also their in-hospital mortality rate is higher (19% vs 11%). The prompt detection of complications often allows an earlier surgical treatment, which represents the best way to improve the outcome 9 10 11 12 .

    Table 7.19
    Structural complications of infective endocarditis .
    Structural complications of infectious endocarditis
    Cusp or leaflet rupture (flail leaflets)
    Perforation
    Abscess formation
    Aneurysms or pseudoaneurysms
    Fistula
    Dehiscence of prosthetic valves
    Formation of intracardiac shunts
    Embolization (systemic, cerebral, pulmonary)

    Table 7.20
    Factors associated with a poor prognosis in right-sided infective endocarditis.
    Factors associated with poor prognosis in right-sided infective endocarditis
    Persistent infection that does not respond to antibiotic therapy
    Patients with worsening tricuspid regurgitation contributing to deteriorating right
    heart failure
    Increase in vegetation size despite antibiotic treatment
    Fungal etiology
    Recurrent septic pulmonary emboli
    Septic shock
    Multivalvular involvement

    Table 7.21
    Indications for surgical interventions for right-sided infective endocarditis.
    Indications for surgical interventions for right-sided infective endocarditis
    Microorganisms difficult to eradicate (e.g., persistent fungi)
    Large, persistent tricuspid valve vegetations (> 20 mm)
    Right heart failure secondary to severe tricuspid regurgitation
    Persistent bacteremia for > 7 d (e.g., Staphylococcus aureus , Pseudomonas aeruginosa ) despite adequate antimicrobial therapy
    Recurrent pulmonary emboli with or without concomitant right heart failure
    Abscess (more common in the setting of prosthetic valve)

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