50% was defined as significant stenosis. Results A 98.7% (778/788) of the coronary artery segments (vessel diameter ≥1.5 mm) could be visualized by 64-slice spiral CT. Compared with catheter angiography in the detection of coronary stenosis, the overall sensitivity, specificity, positive predictive value, negative predictive value and the accuracy of 64-slice CT coronary angiography were 81.9%, 99.0%, 95.9%, 95.1%, and 95.2% respectively. Overall sensitivity would be 91.8% if corrected methodologically. The sensitivity after methodological correction became 91.8%. Conclusion Sixty-four-slice spiral CT examiniation provides a promising non-invasive approach in detecting coronary stenosis with fairly good accuracy, but can not totally replace catheter coronary angiography yet.

OBJECTIVETo investigate the association of desmoplakin with the distribution and function of Nav1.5 by RNA silencing technology in HL-1 cells.

METHODSHL-1 cells with desmoplakin expression suppression by RNA silencing were examined for desmoplakin and Nav1.5 protein expressions by Western blotting, and the distribution and co-location of desmoplakin and Nav1.5 protein were detected by immunofluorescence staining. Patch-clamp recording was applied to analyze the changes in whole-cell sodium current after desmoplakin silencing.

RESULTSCompared with the untreated group and negative control group, the cells with desmoplakin silencing showed obviously reduced expressions of desmoplakin and Nav1.5 proteins. Co-localization of desmoplakin and Nav1.5 was detected at cell-cell contact in untreated and control conditions, and desmoplakin expression silencing induced a drastic redistribution of Nav1.5 with decreased peak current density (156.3∓6.2 vs 41.8∓3.1, n=6, P<0.05), a shift in voltage dependence of steady-state inactivation (-42 mV vs -61 mV, n=5, P<0.05), and prolonged time of recovery from inactivation.

CONCLUSIONDesmoplakin silencing caused redistribution of Nav1.5 protein and also changes in its electrophysiological properties in HL-1 cells.

Animals ; Cell Line ; Desmoplakins ; genetics ; metabolism ; Gene Silencing ; Mice ; Mutation ; Myocytes, Cardiac ; metabolism ; NAV1.5 Voltage-Gated Sodium Channel ; metabolism

UNLABELLEDObjective To compare the impact of right ventricular apical (RVA) versus right ventricular outflow tract (RVOT) pacing on left ventricular systolic synchronization.

METHODSSixty patients were prospectively recruited and randomized into RVA group (n=30) with the right ventricle leads placed in the RVA and RVOT group (n=30) with right ventricle leads placed in the septum of the RVOT. Speckle tracking imaging was performed with 100% ventricle pacing to measure the differences in the time to maximum left ventricle (LV) radial strain.

RESULTSIn RVA group, the difference in the time to 6-segment maximum LV radial strain after pacing was 105.27 ± 19.74 ms, significantly greater than that in RVOT group (41.65 ± 12.17 ms, P<0.001). The standard difference of time to 6-segment maximum LV radial strain was also significantly greater in RVA group than in RVOT group (42.71 ± 17.63 vs 17.63 ± 5.62 ms, P<0.001).

CONCLUSIONLeft ventricle systolic synchronizaition after RVOT pacing is superior to RVA pacing.

Cardiac Pacing, Artificial ; methods ; Heart ; Heart Ventricles ; Humans ; Systole