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Advisor(s)
Abstract(s)
Introdução: O estudo ecocardiográfico bidimensional por speckle tracking (2D-STE) é uma das novas modalidades de avaliação da mecânica cardíaca, baseada na quantificação da deformação miocárdica e de elevada acuidade diagnóstica. Aplicada inicialmente ao estudo da cavidade ventricular esquerda, atualmente tem sido aplicada para o estudo da mecânica ventricular direita e das cavidades auriculares. Objetivo: O principal objetivo deste estudo é avaliar a influência da regurgitação tricúspide (RT) no strain rate da aurícula direita (SRAD) e identificar os fatores que explicam a sua variabilidade. Metodologia: A amostra do estudo contou com 55 indivíduos analisados. A amostra foi dividida em 2 grupos baseando-se no volume regurgitante tricúspide (VRT): Grupo A (n=42) com orifício regurgitante efetivo tricúspide (ORET)<0.40cm2; Grupo B (n=13) ORET≥0.40cm2. O estudo da mecânica auricular foi realizado por SR baseado em 2D-STE. A frame de referência coincidiu com o início do QRS. Resultados: O SRAD da fase de reservatório (SRADR) apresentou um valor mediano de 1.5 (1.2-2.1)s-1 e o SRAD da fase de condução (SRADCD) apresentou um valor mediano de 1.5 (1.2-1.9)s-1, ambos maiores no grupo A. A RT correlacionou-se negativamente com o SRADR e positivamente com o SRADCD (VRT:r=-0.58, ORET:r=-0.53 e o raio de PISA:r=-0.55, todas com P<0.01; VRT:r=0.45, ORET:r=0.40 e o raio de PISA:r=0.41, todas com P<0.01, respetivamente). Analisando os doentes por ritmos verificou-se que a SRADR apresentou diferenças significativas nos doentes com ritmo sinusal (RS) (P<0.01). A análise de regressão linear, demonstrou ser uma variável independentemente associada ao SRADR em doentes em FA apenas o volume da AE (β=-0.33, P=0.05) e em doentes com RS apenas a onda S tricúspide (β=0.48, P<0.01). Conclusões: Este trabalho permitiu abordar um novo método para a avaliação da mecânica auricular direita em contexto de sobrecarga de volume por 2D-STE. De acordo com os resultados apresentados o SRAD foi negativamente influenciado pela sobrecarga crónica de volume da AD.
ABSTRACT - Introduction: Echocardiographic speckle tracking (2D-STE) is one of the new modalities to evaluate cardiac function. It’s useful to access myocardial mechanics with consistent results. Initially applied to left ventricular mechanics, it has now been adapted to the right ventricular and atrial myocardial study. Objective: The purpose of this study is to evaluate the tricuspid regurgitation (TR) influence on right atrial strain rate (SRAD) and identify independent predictors. Methodology: The study sample consisted of 55 individuals, who were referred for transthoracic echocardiography. The sample was divided into two groups based on tricuspid regurgitant volume (VRT): Group A (n=42) with effective regurgitant orifice area (ORET)<0.40cm2; Group B (n=13) ORET≥0.40cm2. The atrial mechanics study was performed by SRAD based on 2D-STE. The reference frame coincided with the onset of the QRS. Results: The SRAD of the reserve phase (SRADR) and conduction phase (SRADCD) presented an medium of 1.5 (1.2-2.1)s-1 and 1.5 (1.2-1.9)s-1, respectively, and both were higher in group A. RT variables presented negative correlations with SRADR and positive with SRADCD (VRT:r=-0.58, ORET:r=-0.53 and the PISA radius:r=-0.55, all with P<0.01, VRT:r=0.45, ORET:r=0.40 and the PISA radius:r=0.41, all with P<0.01, respectively). Analysing patients by rhythm, SRADR presented significant differences and higher values in patients with sinus rhythm (RS) (P<0.01). Linear regression analysis showed to be an independent predictor of SRADR that in atrial fibrillation patients only the left atrial volume (β=-0.33, P=0.05) and for SR patients only the tricuspid S wave (β=0.48, P<0.01). Conclusions: This study was useful to test a recent method for the evaluation of right atrial mechanics in the context of volume overload by 2D-STE. According to the results, SRAD was negatively influenced by the chronic overload of RA volume.
ABSTRACT - Introduction: Echocardiographic speckle tracking (2D-STE) is one of the new modalities to evaluate cardiac function. It’s useful to access myocardial mechanics with consistent results. Initially applied to left ventricular mechanics, it has now been adapted to the right ventricular and atrial myocardial study. Objective: The purpose of this study is to evaluate the tricuspid regurgitation (TR) influence on right atrial strain rate (SRAD) and identify independent predictors. Methodology: The study sample consisted of 55 individuals, who were referred for transthoracic echocardiography. The sample was divided into two groups based on tricuspid regurgitant volume (VRT): Group A (n=42) with effective regurgitant orifice area (ORET)<0.40cm2; Group B (n=13) ORET≥0.40cm2. The atrial mechanics study was performed by SRAD based on 2D-STE. The reference frame coincided with the onset of the QRS. Results: The SRAD of the reserve phase (SRADR) and conduction phase (SRADCD) presented an medium of 1.5 (1.2-2.1)s-1 and 1.5 (1.2-1.9)s-1, respectively, and both were higher in group A. RT variables presented negative correlations with SRADR and positive with SRADCD (VRT:r=-0.58, ORET:r=-0.53 and the PISA radius:r=-0.55, all with P<0.01, VRT:r=0.45, ORET:r=0.40 and the PISA radius:r=0.41, all with P<0.01, respectively). Analysing patients by rhythm, SRADR presented significant differences and higher values in patients with sinus rhythm (RS) (P<0.01). Linear regression analysis showed to be an independent predictor of SRADR that in atrial fibrillation patients only the left atrial volume (β=-0.33, P=0.05) and for SR patients only the tricuspid S wave (β=0.48, P<0.01). Conclusions: This study was useful to test a recent method for the evaluation of right atrial mechanics in the context of volume overload by 2D-STE. According to the results, SRAD was negatively influenced by the chronic overload of RA volume.
Description
Mestrado em Tecnologia de Diagnóstico e Intervenção Cardiovascular - Especialização em Ultrassonografia Cardiovascular
Keywords
Cardiologia Aurícula direita Strain rate Ecocardiografia Speckle tracking Regurgitação tricúspide Cardiology Right atrium Echocardiography Tricuspid regurgitation
Citation
Silva JP. Influência da sobrecarga crónica de volume na mecânica auricular direita [Dissertation]. Lisboa: Escola Superior de Tecnologia da Saúde de Lisboa/Instituto Politécnico de Lisboa; 2017.
Publisher
Instituto Politécnico de Lisboa, Escola Superior de Tecnologia da Saúde de Lisboa