Expression of Concern

BACKGROUND/AIMS: To assess the relationship between left ventricular remodeling as evaluated by strain echocardiography and conventional echocardiography before and after cardiac resynchronization therapy (CRT) in patients with severe heart failure. METHODS: A cross-sectional descriptive study with follow-up comparison before and after CRT. The study included 33 heart failure patients indicated for CRT at the Vietnam National Heart Institute, Bach Mai Hospital from late 2015 to December 2021. RESULTS: Left ventricular end-systolic volume and end-diastolic volume significantly decreased after three months of follow-up (p < 0.001) and showed a strong inverse correlation with QRS recovery (r = 0.65). A positive correlation was observed between changes in left atrial volume index (LAVI) and 4B strain (r = 0.96, p < 0.05). After three months of CRT implantation, positive correlations were observed between isovolumic relaxation time (IVRT) and left atrial volume index (LAVI), and between left atrial volume and E/e' obtained from tissue Doppler imaging (r = 0.53, p < 0.05). No correlation was found between E/e' and total EF, between 2B strain and total EF, or between 2B strain and LAVI. CONCLUSION: Strain echocardiography represents an important tool for diagnosing, assessing risk factors, and monitoring heart failure. After three months of CRT implantation, significant improvement in left ventricular volume and ejection fraction was observed, indicating improved treatment effectiveness.