Left ventricular torsional dynamics in aortic stenosis: relationship between left ventricular untwisting and filling pressures. A two-dimensional speckle tracking study.

ABSTRACT

AIMS: The contribution of left ventricular (LV) untwisting to LV suction and early-diastolic filling was previously demonstrated, but this was not yet tested in patients with aortic stenosis (AS). We sought to assess the relationship between LV untwisting and LV filling pressures in patients with severe AS and normal left ventricular ejection fraction (LVEF) using speckle tracking echocardiography. METHODS AND RESULTS: Sixty-one consecutive patients (66 +/- 9 years) with severe AS, preserved LVEF (63 +/- 6%), and 40 normal subjects (47 +/- 12 years) were prospectively enrolled. A comprehensive echocardiographic examination was performed in all. LV rotation and twisting were assessed using speckle tracking echocardiography. Peak apical back rotation rate, peak LV untwisting rate, and time intervals from QRS onset (ECG) to each of them were measured. Brain natriuretic peptide (BNP) levels were determined in 30 patients. Patients with AS were older than normal subjects (P < 0.001). LV mass, LA volume, LV filling pressures as well as peak apical back rotation rate and time to peak apical back rotation rate were increased in patients (P < 0.05 for all). In patients with AS, both time to peak LV untwisting rate and time to peak apical back rotation rate were significantly related to E/E' ratio and to BNP levels (P < 0.04 for all). CONCLUSION: In patients with severe AS and preserved LVEF, there is a significant relationship between LV untwisting and LV filling pressures, suggesting a role for impaired LV untwisting in the pathophysiology of diastolic dysfunction in this setting.