ABSTRACT
Objective To study midterm curative effect of domestic drug eluting coronary stent in treatment of left main (LM) lesion.Method From April 2004 to September 2005,totally 32 patients with LM lesion received percutaneous coronary intervention (PCI) without protection.Thirty-nine coronary stents (Firebird, Microport,Shanghai) were implanted.One stent was used when the lesion only involved the opening or the middle portion of the LM branch.If the bifurcation was involved,the stenosis was treated considering the following factors: the diameter of left main,left anterior descending (LAD) and the left circumflex branch (LCX);whether there was stenosis of the opening of circumflex branch.Methods included"T"stent,stent pass though the opening of circumflex branch and kissing stents.All patients were followed at 1,6 and 12 months after discharge.Coronary angiography of patients was performd at 5 months after discharge.Central necrosis,restenosis,target vessel reconstructive rate (TVR) and target lesion reconstructive rate (TLR) were analyzed.Results Most LM lesion involved bifurcation (53.1%).Treatment for bifurcation included"T"stent in 47% patients,stent passing through the opening of LCX in 35.3 %.No restenosis occurred in lesion involving the opening or middle portion of the LM during follow-up.The 62.3% patients received coronary angiography.Angiography showed 5% of restenosis rate,5% TLR,10% TVR and 6.3% central necrosis rate.Conclusions Drug eluting stent implantation in low risk unprotective left main lesion may achieve satisfactory clinical results.
ABSTRACT
<p><b>OBJECTIVE</b>Currents contributing repolarization in rabbit ventricular myocyte are very complex since the I(To.s) covers almost the whole repolarization phase of the action potential. The other components of repolarizing currents, as I(Kr) and I(Ks) are small. The purpose of this study is to investigate whether or not there are other currents in rabbit ventricular repolarization.</p><p><b>METHODS</b>Ion currents of rabbit ventricular myocyte were recorded using the whole-cell patch-clamp technique.</p><p><b>RESULTS</b>In the present work, an nonselective cation current was identified by replacing the K(+) with Cs(+) in the bathing and pipette solutions. The outward current elicited by depolarizing potentials could be inhibited by Gd(3+), an effective inhibitor of nonselective cation currents. Depleting Ca(2+) and Mg(2+) in the bathing solution, the amplitudes of this outward current increased by 40%-116% at +60 mV, and adding 2 micromol/L insulin to the solution (with normal concentration of Ca(2+) and Mg(2+) in Tyrode's solution), the amplitude increased by 30%-60% at +60 mV.</p><p><b>CONCLUSION</b>It is suggested that a nonselective cation current in rabbit ventricular myocytes may play an important role in the repolarization of the action potential in rabbit ventricle. Changes of nonselective cation current will lead to induce or inhibit arrhythmia.</p>
