Isovolumic Relaxation Strain Imagingは、アクティブな拡張期機能不全の検出において正確かつ高感度なアプローチである：前臨床研究

Currently, there is no imaging-based method for directly detecting active diastolic dysfunction. This study aimed to evaluate the efficacy of isovolumic relaxation strain imaging (IVSI) in assessing active diastolic dysfunction in preclinical settings.

Active diastolic function was assessed in C57BL/6J mice subjected to transverse aortic constriction (TAC) or a sham operation using daily conventional echocardiography and strain imaging over a 14-day period, with follow-ups at weeks 4 and 8. A modified approach was developed to accurately identify the isovolumic relaxation time (IVRT) using an apical three-chamber view.

The novel imaging protocol successfully identified IVRT in each mouse. TAC mice exhibited significant alterations in E/A and E/E' ratios from day 12 to 14, while the average strain rate detected by IVSI showed a significant decrease from day 4. After 8 weeks, TAC mice developed severe heart failure with reduced ejection fraction, but conventional echocardiography failed to detect diastolic dysfunction.

IVSI continued to indicate obvious diastolic alterations. Together, these data suggested that IVSI is an effective imaging-based method for direct detection of active diastolic dysfunction with high accuracy and sensitivity.