Abstract 2292: Torsional Deformation Delay: a Novel Echocardiographic Index of Left Ventricular Peak Rotation Sequence Between Basal and Apical Level.
Purpose: left ventricular (LV) torsion (TOR) results from oppositely directed rotation (ROT) at the basal (BAS) and apical (AP) level. Speckle Tracking Echocardiography (STE) allows TOR assessment, but little is known of LV ROT temporal distribution. The aim was to evaluate the sequence of BAS and AP level ROT and to identify associated echocardiographic parameters.
Methods: 48 patients (PTS) were studied (mean age 54±13 years, 23 men). LV systolic function was normal in 23 PTS (LVEF 60% or more), and various degrees of dysfunction were present in 25 PTS (mean LVEF 40±10%). Digital short axis loops at BAS and AP level were analyzed using STE algorithm to measure ROT in degrees (°). After adjustment for heart rate, Torsional Deformation Delay (TDD) was calculated as the difference between the time from the onset of QRS complex to the peak average systolic ROT at BAS and AP level (figure⇓).
Results: mean TOR, BAS ROT and AP ROT was 14.3±7.3°, −6.8±4.7° and 7.5±6.1° respectively. Mean TDD was 19±107 ms (range from −285 to 248 ms); negative TDD indicated shorter time to BAS peak ROT. No difference of mean TDD was found between PTS with normal and decreased LVEF. TDD outside the range of −28 ms to 28 ms, derived by ROC analysis, was shown to have 96% specificity in detecting PTS with LVEF <60%. It was also associated with higher LV mass index as compared to TDD ranging from −28 to 28 ms (130 g/m2 vs 100 g/m2, p=0.025).
Conclusions: a novel TDD index allows evaluation of LV ROT temporal distribution between BAS and AP level. TDD values outside the range of −28 ms to 28 ms are associated with decreased LVEF and presence of LV hypertrophy. Further studies are required to assess the role of TDD in cardiac imaging.