ABC | Volume 113, Nº1, July 2019

Statement Position Statement on Indications of Echocardiography in Adults – 2019 Arq Bras Cardiol. 2019; 113(1):135-181 posterior approach to the heart, achieves better diagnostic precision in valvular prosthesis dysfunctions. In fact, TTE and TEE complement each other, since the TTE better evaluates the changes in flow and TEE, the morphological changes. It is always advisable to carry out the full and careful TTE before recommending the TEE. The 3D TEE 160 provides additional information about the 2D image, particularly regarding the spatial relationship of the structures around the prosthesis, the direction and extent of regurgitant jets, the location of paravalvular leaking and the identification, position and number of larger anomalous prosthetic or periprosthetic echoes, potentially more embolinogenic. 161 The diagnosis of prosthesis stenosis should always be performed with the extensive use of echocardiography. The transprosthetic gradients are variable in each model and size, and there may be high gradients in cases of small, even normal, prostheses when implanted in large body surface patients, a finding known as mismatch. 162 Patients who remain with significant LVH in the late postoperative period may also present elevated gradients after aortic prosthesis implantation. Thus, the comparison with the basal echocardiography is always important. In biological prostheses, the most frequent cause of stenosis is the degeneration and calcification of the leaflets, usually a late complication. In mechanical prostheses, the growth of fibrous tissue into the ring, known as pannus, is also a late complication that can cause stenosis, reflux, or double prosthetic dysfunction. The detection and quantification of the reflux of the prostheses are usually hampered by the acoustic shadow caused by the mechanical prostheses, mainly in the mitral position. In such cases, TEE can aid in the detection and quantification, and determine if the insufficiency is prosthetic or periprosthetic, functional or pathological. We must be careful in differentiating the “physiological” refluxes, which are common in prostheses, from the pathological ones. 163 In general, physiological reflux presents laminar flow at color Doppler and pathological reflux presents a turbulent, color mosaic flow. In cases of suspicion of infective endocarditis in prosthetics, the diagnosis is made difficult by the presence of shadows and reverberations, allowing the TTE to identify only the large vegetation. Given the clinical suspicion of endocarditis, it is always advisable to perform the TEE, which has greater sensitivity, detecting smaller vegetations and possible complications, such as annular abscesses (Table 29). 3D TEE allows a more precise spatial localization, in relation to the adjacent prosthetic and anatomical structures, of potentially emboligenic vegetations. In cases of embolic phenomena or acute stenosis of the prosthesis, especially in the mitral position, the presence of valve thrombosis or strands (fibrin) should be suspected, with TTE and TEE being indicated (3D TEE, if possible) in order to overcome the acoustic shadow and better observe the LA and the atrial face of the prosthesis. In these cases, in addition to looking for thrombi or fibrin in the valve or the LA, the prosthesis’ mobile structures and the emboligenic potential of the thrombi should be functionally evaluated (Table 30). Table 28 – Recommendations of echocardiography in valvular prostheses Recommendation Class of recommendation Level of evidence TTE in patients with valve prostheses with changes in clinical signs or symptoms, suggesting prosthetic dysfunction (stenosis or insufficiency) I A TEE in patients with prosthetic dysfunction to TTE, for confirmation and better quantification of dysfunction IIa B Periodic reassessment in patients with prosthesis, with ventricular dysfunction without modification of symptoms or clinical signs IIa B Periodic reassessment in biological valve prostheses without signs or symptoms of prosthetic dysfunction IIb B TTE: transthoracic echocardiography; TEE: transesophageal echocardiography. Table 29 – Recommendations of echocardiography in infective endocarditis in patients with valve prostheses Recommendation Class of recommendation Level of evidence Detection and characterization of the valve lesion and evaluation of the hemodynamic repercussion* I B Detection of complications such as abscesses, ruptures and fistulas* I B Reevaluation in cases with poor clinical evolution* I B Suspected endocarditis in patient with negative cultures* I B Bacteremia of unknown etiology* I B Persistent fever with no evidence of bacteremia or new murmurs* IIa B Routine assessment during treatment of uncomplicated endocarditis* IIb B Transient fever without evidence of bacteremia or new murmur* III B * Transesophageal echocardiography may give additional information to those obtained with transthoracic echocardiography. 159