超声心动图评价扩张型心肌病患者冠状动脉内皮功能及维生素C的急性作用

Epicardial coronary endothelial dysfunction in patients with idiopathic dilated cardiomyopathy and the acute effects of vitamin C

目的 :应用二维超声心动图测量扩张型心肌病患者冷加压试验前后左冠状动脉主干内径的百分变化率评价冠状动脉内皮功能 ;并用此方法评价维生素C静脉注入对其冠状动脉内皮功能的影响。方法 :研究对象包括 2 1例扩张型心肌病患者和 18例健康对照者。分别于维生素C静脉注入前后 ,应用超声心动图测量静息状态下、冷加压负荷试验后、舌下含服硝酸甘油后的左冠状动脉主干内径 ,并计算冷加压负荷试验和硝酸甘油诱发的左冠状动脉主干内径百分变化率。结果 :冷加压试验前后左冠状动脉主干内径百分变化率扩张型心肌病患者明显低于正常人 (P <0 .0 0 1) ,硝酸甘油诱发的左冠状动脉主干内径百分变化率扩张型心肌病组和健康对照组 (P =0 .5 8)差异无显著性意义 ;维生素C静脉注入后 ,18例扩张型心肌病患者冷加压试验前后左冠状动脉主干内径百分变化率明显高于静脉注入前 (P <0 .0 0 1) ,但硝酸甘油诱发的左冠状动脉主干内径百分变化率与静脉注入前 (P =0 .3 9)差异无显著性意义。结论 :扩张型心肌病患者冠状动脉内皮功能减低 ;

Objectives:To evaluate coronary endothelial function in patients with idiopathic dilated cardiomyopathy using the cold pressor test induced percent change in the left main coronary diameter determined by transthoracic echocardiography, and to investigate the acute effects of vitamin C on the coronary endothelial function in these patients.Methods: Twenty one patients with idiopathic dilated cardiomyopathy and eighteen healthy subjects underwent assessment of coronary endothelial function during cold pressor test and sublingual nitroglycerin administration. Measurements of cold pressor test induced and nitroglycerin induced percent changes in the left main coronary diameter by transthoracic echocardiography were performed before and after the acute intravenous administration of vitamin C.Results:The percent change in the left main coronary diameter induced by cold pressor test in patients was significantly less than that in healthy subjects ( P < 0.001). No significant difference could be found in percent change in the left main coronary diameter induced by sublingual nitroglycerin between the patients and the controls ( P =0.58).Intravenous infusion of vitamin C significantly increased the percent change in the left main coronary diameter induced by cold pressor test in 18 patients ( P <0.001).No significant change could be found in percent change in the left main coronary diameter induced by sublingual nitroglycerin in 18 patients after the intravenous administration of vitamin C ( P =0.39).Conclusions:The decreased percent change in the left main coronary diameter induced by cold pressor test in patients with idiopathic dilated cardiomyopathy compared to the healthy subjects indicates that coronary endothelial function is impaired in the patients. The intravenous administration of vitamin C can improve coronary endothelial function in the patients.