Background: Left ventricular torsion (LVtor) and subsequent untwisting play an important role in diastolic filling. There is, however, limited information about how LVtor and untwisting are related to the severity of diastolic dysfunction. The aim of this study was to assess LVtor and untwisting in the progressive severity of diastolic dysfunction.
Methods: We studied 148 subjects (116 with diastolic dysfunction, 32 healthy controls). Apical and basal short-axis rotations were measured by 2-dimensional speckle tracking echocardiography. LVtor was defined as the instantaneous net difference of the basal and apical rotation. Patients were divided into 3 groups according to diastolic dysfunction grade and their underlying disease, such as hypertension, hypertrophic cardiomyopathy, and amyloidosis.
Results: Age, gender, and ejection fraction were similar in the 3 groups and control. Mitral annulus early diastolic velocity was reduced by design in all 3 groups. Peak LVtor was significantly greater in mild diastolic dysfunction (n = 45; 29.7 +/- 9.0 degrees) compared with control (n = 32: 15.6 +/- 4.0 degrees) and then normalized in moderate (n = 49; 19.3 +/- 4.8 degrees) and severe diastolic dysfunction (n = 22; 17.3 +/- 9.3 degrees). The twisting and untwisting rates were significantly higher in mild diastolic dysfunction group.
Conclusion: Systolic torsion and diastolic untwisting are significantly increased in patients with mild diastolic dysfunction. In patients with advanced diastolic dysfunction with increased filling pressure, they are normalized or reduced. Whether increased LVtor is a compensatory mechanism for reduced myocardial relaxation or a consequence of reduced filling in the early stage of diastolic dysfunction requires further investigation. Analysis of LVtor with speckle tracking echocardiography should be further explored to elucidate the role of torsion in patients with diastolic dysfunction.