PoCUS may reveal cardiac masses, thrombi, or vegetations, which should not be ignored. These findings should trigger further evaluation with consultative echocardiography when available.
Thrombi (blood clots) are the most common intra-cardiac mass/lesion seen on ultrasound.1 They can be found in any chamber, and are associated with reduced blood flow, decreased wall motion, local inflammation, and hypercoagulable states.2
Image 8.1 Apical 4-chamber view of LV thrombus visible near the cardiac apex.
Image 8.2 IVC (A) and A4C (B) views revealing a mobile RA thrombus and RV dilation such that it is larger than the LV. This finding rules in the diagnosis of isolated RV overload due to pulmonary embolism.
PoCUS can be specific but not sensitive to diagnose cardiac thrombi.3 When seen, LV thrombi have well-defined borders, appear hyperechoic, and separate from the endocardium (chamber wall). To differentiate thrombi from normal trabeculations, papillary muscles, tendineae, pacemaker leads, cardiac catheters, focal wall hypertrophy, or ultrasound artifacts, assess the lesion from multiple angles and optimize each view.
Thrombi signify high thromboembolic risk, especially when the thrombus is large, protrudes into the chamber cavity, or is associated with older age or reduced ejection fraction.4 Thus, if PoCUS can easily detect a cardiac thrombus, it's specific for thromboembolic risk. Although randomized controlled trials specific to LV thrombi are lacking, three or more months of anticoagulation therapy is associated with significantly fewer major adverse cardiovascular events.5
Vegetations are fibrinous lesions that form on endocardial surfaces that experience injury from turbulent flow or implanted endovascular devices. Endothelial injury activates the clotting and immune systems, which seeds vegetations that become infected via transient bacteremia. Infection of vegetations (endocarditis) compounds endothelial damage and stimulates vegetation growth. The following lists risk factors and complications of infective endocarditis.6,7
Risk Factors for Infective Endocarditis
Potential Complications of Infective Endocarditis
Image 8.3 PLAX views showing multiple perivalvular lesions (arrows in C), with CDI (B) revealing significant aortic valve insufficiency in a patient with respiratory failure, fever, and a significant diastolic murmur.
PoCUS using color-Doppler imaging (CDI) or B-mode may reveal valve insufficiency. Vegetations are often visible on a leaky valve's lower pressure (back) side. They are usually isoechoic to cardiac tissue and mobile (oscillate independently). Something may look like a vegetation but be an artifact, thrombus, flailing valve leaflet, ruptured papillary muscle, embryonic remnant, or valve calcification. The modified Duke criteria, updated to include new imaging and laboratory techniques,7 continue to be the recommended tool for diagnosing infectious endocarditis. If PoCUS reveals a vegetation or suspicious new valvular insufficiency, this should prompt immediate evaluation with blood cultures and consultative imaging. If the probability of infectious endocarditis is moderate to high, cardiac views are suboptimal, or a prosthetic valve is present, then transesophageal echocardiography, if available, is indicated to either rule out endocarditis or identify local complications that impact management.8 However, in settings where further imaging and surgery are unavailable, consider using PoCUS findings of valve insufficiency or possible vegetation in the modified Duke criteria. If the criteria are sufficient, look for and address other foci of infection and treat with a prolonged course of effective antibiotics based on local standards and guidelines.
Do not rely on PoCUS alone to rule out the presence of infective endocarditis, as identifying vegetations may require transesophageal views of the valves with clips saved and carefully reviewed frame-by-frame.
Metastatic tumors originating elsewhere are the most common neoplasms involving the heart. Metastasis usually involves the pericardium, including presentations of hemorrhagic pericardial effusion with tamponade. Invading malignancy can originate from anywhere, though melanoma and local thoracic cancer are more common. Myocardial involvement may cause arrhythmias and other ECG changes, and associated cardiac dysfunction may be hard to differentiate from the effects of cardiotoxic antineoplastic agents. Endocardial involvement is less common and usually occurs in the right heart, involving tumors with endovascular growth, such as renal, liver, and uterine cancers.9
Image 8.4 PLAX (A) and A4C (B) views of a large mass compressing the left atrium in a patient with progressive dysphagia and weight loss found to have advanced esophageal cancer.
Primary cardiac tumors are rare (~0.02% in autopsy series and 0.1% in an echocardiography series), and most are benign.10,11 Cardiac myxomas are the most common primary cardiac tumor and usually arise from and are attached to a signal point in the interatrial septum in the left atrium, though sometimes the right atrium. Benign primary tumors can form at any location in the heart and be found incidentally or in association with symptoms related to their location, such as features of right heart failure in right-sided tumors, mitral stenosis in LA tumors, outflow tract obstruction in ventricular tumors, and valve insufficiency in valvular tumors. Embolization, fevers, myalgias, and weight loss can also occur. Malignant tumors, usually sarcomas, more often involve multiple sites, arrhythmias, refractory heart failure, and the pericardium.12
Image 8.5 An A4C view that incidentally revealed a LA lesion attached to the interatrial septum that is likely an atrial myxoma.
If PoCUS reveals a suspicious lesion, whether a tumor, vegetation, or thrombus, the patient will benefit from further evaluation with consultative imaging. However, if additional imaging and referral are unavailable, consider the diagnosis of endocarditis (modified Duke criteria). If endocarditis is unlikely, consider whether the patient benefits from anticoagulation therapy. Do this by weighting the likelihood of bleeding complications versus your certainty that the lesion is a thrombus or associated with thromboembolic events.