Abstract and Introduction
The echocardiographic diagnosis of cardiac thrombi, vegetations and tumors as well as the identification of predisposing conditions such as patent foramen ovale, aortic atherosclerosis and other minor causes (e.g., mitral valve prolapse, mitral and aortic valve calcification) have crucial clinical relevance, affecting the choice of surgery and/or of pharmaceutical therapy in the setting of patients presenting embolism. The echocardiographic assessment helps not only for the retrospective diagnosis of sources of embolism but also for the prevention of events in asymptomatic patients. Echocardiography can also distinguish normal variants and artifacts from cardiac masses and tumors. Echocardiographic characterization/typology of cardiac sources of embolism is currently below par when compared with cardiac MRI, the current gold standard. Nevertheless, echocardiography remains the 'first-line' imaging tool, because of its low cost and the possibility to add easily available, functional and structural information at the patient's bedside.
In the pre-echocardiographic age, the diagnosis of cardiac sources of embolism was predominantly postmortem and no possibility of therapeutic intervention was available. With the onset of 2D echocardiography, it has become possible to establish not only the existence, but also the features of cardiac masses that represent sources of embolisms. Nowadays echocardiography is considered the primary tool for the diagnosis of cardiac masses and tumors, with a sensitivity of 93% for transthoracic echocardiogram (TTE) and 97% for transesophageal echocardiogram (TEE). Although TTE is useful for the initial evaluation of cardiac masses, TEE is often needed, in particular to visualize small masses localized into atria and appendages or adherent to the cardiac valves. TEE is also responsible for 11% of diagnoses of cardiac masses in patients with stroke. The criteria needed for diagnosis of a cardiac mass include localization, dimensions, shape, tissue characteristics, mobility, site of attachment and the presence or absence of myocardial infiltration.
Cardiac MRI represents the gold standard for characterization/typology of cardiac sources of embolism, although it has never proven to be superior to TEE for detection of vegetations. In this field PET also presents interesting applications. Nevertheless, echocardiography remains the 'first-line' imaging tool, because of its low cost and the possibility to add easily available, functional and structural information at the patient's bedside.
The diagnosis of cardiac thrombi, vegetations and tumors has a crucial clinical relevance, addressing deeply the therapeutic management and the eventual choice of surgery. Also major predisposing conditions such as patent foramen ovale (PFO) and aortic atherosclerosis, as well minor conditions (e.g., mitral valve prolapse, mitral annular calcification and calcified aortic stenosis) can be identified by cardiac ultrasound. The echocardiographic screening helps not only for retrospective diagnosis of embolic events (embolic sources) but also for prevention of events in asymptomatic patients. Major and minor sources of embolism can be suspected or detected by an ultrasound assessment (Box 1). Echocardiography can also distinguish normal variants and artifacts from cardiac masses and tumors (Table 1). The echocardiographer must be aware that not every 'mass' is a pathological structure and they have to differentiate artifacts and normal variants seen during TTE and TEE from real abnormal masses.
Future Cardiol. 2012;8(1):101-114. © 2012 Future Medicine Ltd.