The relationship between QT dispersion and coronary artery stenosis and the effects of stent implantation on QT dispersion in the patients with severe coronary artery stenosis

Objective To find out the relationship between QT dispersion(QTd) and the abnormality of the extent and range of coronary artery stenosis.To find out the effects of the treatmeats by stent implantation on QTd in the patients of coronary heart disease.Methods The abnormality of the extent and range of coronary artery stenosis and QTd were recorded among 119 patients receiving coronary angiography.27 patients with severe coronary artery stenosis underwent stent implantation,the !change of QTd were recorded after stent implantation with ECG.Results ①The QTd of the patients with light stenosis group(49.4±10.6ms) compared with normal coronary artery(46.7±10.3ms) were no significant difference(P0.05).However,the QTd of the patients of the severe stenosis group(68.5±10.7ms) were increased(P0.01) compared with the medium stenosis group(60.8±10.5ms),as well as the medium stenosis group compared with light stenosis group(P0.01).②The QTd of the patients with lesion of singe-vessel disease(55.3±10.4ms) were significantly increased compared with the patients with normal coronary artery(p0.01).The QTd of muliti-vessel disease group(69.3±10.1ms) were longer than double-vessel disease group(62.5±10.2ms),double-vessel disease group were longer than singe-vessel group,respectively(p0.05).③In severe stenosis group,the QTd were significantly reduced after stent implantation(44.9±10.1ms) compared with that with before operation(P0.01).Conclusion QTd helps to reflect the extent and range of coronary artery stenosis.Successful stent implantation can reduced QTd of the patients with severe coronary artery stenosis.