ABSTRACT
<p><b>UNLABELLED</b>Objective To compare the impact of right ventricular apical (RVA) versus right ventricular outflow tract (RVOT) pacing on left ventricular systolic synchronization.</p><p><b>METHODS</b>Sixty 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.</p><p><b>RESULTS</b>In 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).</p><p><b>CONCLUSION</b>Left ventricle systolic synchronizaition after RVOT pacing is superior to RVA pacing.</p>
Subject(s)
Humans , Cardiac Pacing, Artificial , Methods , Heart , Heart Ventricles , SystoleABSTRACT
<p><b>OBJECTIVE</b>To investigate the association of desmoplakin with the distribution and function of Nav1.5 by RNA silencing technology in HL-1 cells.</p><p><b>METHODS</b>HL-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.</p><p><b>RESULTS</b>Compared 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.</p><p><b>CONCLUSION</b>Desmoplakin silencing caused redistribution of Nav1.5 protein and also changes in its electrophysiological properties in HL-1 cells.</p>
Subject(s)
Animals , Mice , Cell Line , Desmoplakins , Genetics , Metabolism , Gene Silencing , Mutation , Myocytes, Cardiac , Metabolism , MetabolismABSTRACT
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.