Ecocardiograma 2D e 3d para avaliar o remodelamento reverso pós-terapia ressincronização cardiaca: qual sua real aplicação? O eco 3D melhorou a avaliação feita pelo eco 2D?

Abstract

Cardiac Resynchronization Therapy (CRT) has proven effective when combined with treatment with conventional drugs in patients refractory to medical treatment, with severe ventricular dysfunction, conduction disturbances, dyssynchrony and chronic heart failure (CHF) functional class III and IV .Several studies have shown that CRT significantly improves symptoms, exercise tolerance and quality of life. However, 20% to 30% of patients do not improve with CRT. The probable cause of failure is the fact that mechanical dyssynchrony is not always related to electrical dyssynchrony, and the greater the mechanical dyssynchrony, the better the response to TRC 2 .The echocardiographic markers that indicate patient improvement with CRT are: increased heart rate, decreased degree of mitral regurgitation, reduction of ventricular remodeling and reduction of intraventricular delay.Technological progress of equipment allows carrying out a more accurate assessment of left ventricular reverse remodeling, whose importance has been demonstrated by studies in the literature with increasing frequency. Since the initial studies of volumes by the M-mode, two-dimensional mode, and more recently by 3D echo, as done in this study, much has been learned in this field 3 .Real-Time Three-Dimensional Echocardiogram (RT3DE) represents a new technique to identify patients with CHF who may or may not be considered for CRT quantifying LV function and its dyssynchrony.The software application used by current RT3DE devices helps the correction of edges, thus providing a more accurate RT3DE. Only markedly increased left ventricle diameters make it difficult to capture the image at full volume. In this study, the correlations of volumes and left ventricle ejection fraction were excellent between 2D and 3D modes. Only the mass calculated by the 3D was superior to 2D echo. The semiautomatic measure of the endocardial surface by the RT3DE is fast, accurate and reproducible of volumes, reported in the literature as superior to the volumes calculated by 2DECHO 4 , which differs from that observed in this study, which showed no superiority of 3DECHO for the calculation of volumes 3 .Large studies that validate RT3DE definitively have not been undertaken yet. The RT3DE can assist in choosing the best location for the implantation of the pacemaker (PM) and monitor the patient 5 . Zhang et al 6 studied 13 patients after CRT and showed that the shutdown of PM determined asynchrony, increased volumes and decreased ejection fraction, indicating the importance of this analysis in selecting patients for CRT and predicting favorable responses.In a recent review on this issue, Auger et al 7 studied 166 patients after CRT with Doppler tissue imaging (TSI) and RT3DE (real-time 3D echo), showed that the response to CRT was positive in 86.3% of patients when the two methods showed the presence of dyssynchrony, and the response was negative in 97% of patients when either method showed no dyssynchrony. They concluded that the evaluation of dyssynchrony allows a more accur...