Relation of Diastolic Dysfunction to the LV Twist and Untwist Dynamic: Speckle Tracking Imaging Study
Background: There is no single noninvasive index that can directly assess diastolic function. Untwist, contributes to diastolic suction, early filling. Speckle tracking imaging (STI), can be used to study the relation between diastolic indices and untwist in patients with diastolic dysfunction.
Patients and methods: 75 patients with diastolic dysfunction and 25 normal volunteers were selected for this study. According to mitral flow pattern they were classified into Group I (abnormal relaxation), Group II (pseudo-normalized) and group III (stiffness pattern) Using STI, the basal and apical short axis views were imaged. Stored data were processed to get apical and basal rotation, systolic twist, peak systolic twist ratio, diastolic untwist ratio and time to peak twist and untwist ratio.
Results: peak untwisting ratio was significantly higher in Group I Patients that decreased to be normalized and even decreased with progression of diastolic dysfunction from grade II to Group III. There was a highly significant positive and negative correlation with EDV and ESV, respectively. Time to peak untwist ratio non-significantly increased from Group I to III with non significant correlation between untwist ratio and peak E, A, and E/A ratio.
Conclusion: patients with relaxation abnormality have a higher untwist ratio that decrease gradually with progression from relaxation to stiffness pattern. It may appear as a compensatory mechanism to assure early filling with relaxation abnormality.