Objective The intracardiac electrocardiogram (ecg) positioning technology in the clinical appli -cation of PICC catheter tip to locate effect were discussed .Methods 115 cases of our department in October 2013-2014 December PICC placement of patients admitted to the study .All patients completed according to uniform pro -cedures catheter, and the use of intracardiac electrocardiogram positioning technology in the catheterization process PICC catheter tip positioning, again catheter positioning X -ray film.Results Intracardiac electrocardiogram PICC tip into the superior vena cava sensitivity of 93.03%, and the situation is a total of seven cases no P wave changes , the rest of the patient P or T wave changes .X -ray showed 108 cases of catheter tip is located on the within the vena cava, and two cases in the subclavian vein (intravenously to two cases of circular motion , resulting in a circular mo-tion intravenous catheter insufficient length , which does not reach the superior vena cava ), and two cases in the inter-nal jugular vein, three cases in the brachial vein .Conclusion PICC catheter tip positioning taking intracardiac elec -trocardiogram positioning technology , with high sensitivity and specificity , which can be clinical application .

Objective To explore the clinical features diagnosis and treatment of left main coronary artery (LM) disease. Methods According to the results of coronary angiography,significant stenosis was defined as ≥50% stenosis. Isolated LM group had 9 patients (4.62%),one-vessel stenosis LM group 15 patients (7.69%),two-vessel stenosis LM group 53 patients (27.18%) and three-vessel stenosis LM group 118 patients (60.51%). Results 195 cases (6.74%) of LM stenosis were found. The incidence rate was low. 164 patients (84.1%) had unstable angina,and 125 patients (64.1%) had myocardial infarction. Coronary artery bypass surgery was performed in 57 patients (29.2%) and the angina disappeared in most of them (84.2%). Five patients received unprotected LM stenosis and angina disappeared in all. Conclusion LM stenosis has sever symptoms. Coronary angiography is the only way for diagnosis and CABG the best treatment. Unprotected LM stenosis is valuable for some patients.