Study of left ventricular torsional mechanics in patients with premature ventricular complexes from right ventricular outflow tract / 中华超声影像学杂志

ABSTRACT

Objective To assess alternations in left ventricular( LV) torsion parameters in healthy subjects and patients with premature ventricular complexes ( PVCs) from the right ventricular outflow tract (RVOT) .Methods ThirtypatientswithPVCsfromRVOTand31healthysubjectswereincluded.Two-dimensional speckle tracking imaging( 2D-STI) was applied to evaluate LV torsion parameters ,including LV rotational degrees in basal and apical levels respectively ,LV total torsional degrees ,and time to peak rotational and torsional degrees . All values of patients with PVCs were recorded during both sinus beats ( PVC-S) and premature ventricular beats ( PVC-V) . Results No significant difference was observed in left ventricular ejection fraction(LVEF) between PVC-S group and control subjects( P > 0 .05) ,while LV rotational degrees in apical levels[( 8 .47 ± 3 .54)° vs (9 .50 ± 3 .21)° , P = 0 .042] and LV total torsional degrees [ (11 .25 ± 6 .31)° vs (14 .00 ± 4 .07)° , P =0 .046] were significantly reduced in PVC-S group . In addition to the reduction of LV rotational degrees in apical levels[( 3 .93 ± 7 .23)° vs (9 .50 ± 3 .21)° , P =0 .000] and LV total torsional degrees[ ( 4 .35 ± 9 .62)° vs (14 .00 ± 4 .07)° , P =0 .000] ,lower apical levels[ ( -0 .57 ± 4 .44)° vs ( -5 .26 ± 3 .84)° , P =0 .000] and advanced LV rotational degrees [ ( 40 .5 ± 18 .6)％vs (48 .0 ± 9 .1)％ , P =0 .05] in basal levels were observed in PVC-V group in comparison with the control subjects . Compared with the PVC-S group ,PVC-V group showed lower LV rotational degrees in basal levels [ ( -0 .57 ± 4 .44)° vs ( -4 .57 ± 4 .57)° , P = 0 .000] and advanced time to peak rotational degrees [ (40 .5 ± 18 .6)％ vs (48 .1 ± 12 .6)％ , P =0 .018] ,as well as advanced time to peak and lower LV total torsionaldegrees[(39.3±15.4)％ vs(46.7±13.8)％ ,P =0.007 ;(4.35±9.62)°vs(11.25±6.31)°,P=0 .001] .Conclusions As to RVOT-PVC patients ,LV myocardial torsional motion has changed in PVC-S mainly manifested as a decrease of rotation degrees in apical levels even if the LVEF is still in the normal range . During PVC-V the rotation and twist degree is further reduced ,and the time sequence altered , accompanied with significantly decreased LVEF .