Impacts of establishment of chest pain center on the door-to-balloon time and the short-term outcome after primary percutaneous coronary intervention of patients with ST segment elevated myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the impact of the establishment of chest pain center (CPC) model based on the pre-hospital real-time tele-12-lead electrocardiogram on the door-to-balloon (D-to-B) time and short-term outcome after primary percutaneous coronary intervention (PPCI) of patients with ST-segment elevated myocardial infarction (STEMI).</p><p><b>METHODS</b>A regular CPC was established with pre-hospital transmitted real-time 12-lead electrocardiogram system for pre-hospital diagnosis of STEMI and enabled the STEMI patients to bypass the emergency room and directly treated in the catheter lab to shorten the D-to-B time. The mean D-to-B time, the short-term outcome and medical costs were compared in PPCI patients before (93 cases, group A) and after (149 cases, group B) the establishment of CPC.</p><p><b>RESULTS</b>After the establishment of CPC, the annual mean D-to-B time was significantly shortened [(127 ± 79) min in group A vs.(72 ± 23 )min in group B, P < 0.01], the shortest monthly mean D-to-B time was remarkably reduced in group B than in group A [(56 ± 11) min vs. (73 ± 14) min, P < 0.01]. The annual ratio of D-to-B below 90 minutes was significantly increased from 62.4% (58/93) in group A to 91.9% (137/149) in group B (P < 0.05) . The in-hospital mortality rate tended to be lower and the incidence of heart failure during hospitalization was significantly reduced in group B compared with group A [3.4% (5/149) vs. 6.5% (6/93), P > 0.05; 14.1% (21/149) vs. 24.7% (23/93), P < 0.05]. The length of hospital stay was slightly shortened from (8.98 ± 4.89) days to (7.79 ± 5.43) days (P > 0.05). Corrected mean medical cost went down by 9.4% (P < 0.05).</p><p><b>CONCLUSION</b>The establishment of CPC may significantly shorten the D-to-B time, improve the short-term outcome and reduce the hospitalization cost for PPCI patients with STEMI.</p>

Reverse 201Tl myocardial redistribution induced by coronary artery spasm / 中华核医学杂志

Objective To investigate the mechanism of reverse redistribution (RR) on dipyridamole 201Tl myocardial perfusion studies in the patients with coronary artery spasm. Methods Twenty-six patients with coronary artery spasm and presented as RR on dipyridamole 201Tl myocardial perfusion studies were enlisted as RR group, while other 16 patients with no coronary artery stenosis nor RR were enlisted as control group. Dipyridamole test was repeated during coronary angiography. Corrected thrombolysis in myocardial infarction (TIMI) frame count (CTFC) and TIMI myocardial perfusion grade (TMPG) were measured at RR related and non-RR related coronary arteries before and after dipyridamole infusion respectively.All of the data were analyzed by Student's t-test orχ2-test and correlation analysis. Results Coronary artery angiography showed slower blood flow and lower myocardial perfusion in RR related vessels when compared with non-RR related vessels in RR group, but there was no significant difference among the main coronary arteries in control group. The perfusion defects of RR area at rest were positively related to slowerblood velocity at corresponding coronary arteries ( r = 0.79, t = 10.18, P ＜ 0.001 ). In RR related vessels,CTFC were (36 ±6) frames and (26 ±7) frames (t =4.15, P ＜0.01 ), while TMPG were (2.02 ±0.39)grades and (2.92 ± 0.12) grades ( t = 2.25, P ＜ 0.05 ) before and after dipyridamole infusion, respectively.In non-RR related vessels, CTFC were (29 ±7) frames and (25 ±5) frames (t =2.31, P ＜0.05), while TMPG were (2.56 ± 0.31 ) grades and (2.96 ± 0.06) grades ( t = 2.17, P ＜ 0.05 ) before and after dipyridamole infusion, respectively. However, there were no significant changes of CTFC and TMPG before and after dipyridamole infusion in control group ( t = 0.932, 0.867, respectively, both P ＞ 0.05 ). Conclusion RR is related to the decreased blood flow and myocardial perfusion induced by coronary artery spasm at rest,which may be improved by stress test such as intravenous dipyridamole infusion.

Clinical features of idiopathic ventricular tachycardia of various types and their radiofrequency ablation therapy / 南方医科大学学报

<p><b>OBJECTIVE</b>To analyze the clinical features idiopathic ventricular tachycardia (IVT) and evaluate the effect of radiofrequency ablation therapy for their management.</p><p><b>METHODS</b>An retrospective analysis was conducted in 165 IVT patients who received radiofrequency ablation therapy. IVT was classified into 3 types according to the site of origin, namely the right ventricular outflow tract (RVOT-IVT, 86 cases), left ventricular septum (LV-IVT, 75 cases), and left Valsalva sinus (4 cases).</p><p><b>RESULTS AND CONCLUSION</b>RVOT-IVT was more frequent in female patients than in male patients (60 vs 26, M/F ratio of 0.43). In LV-IVT, male patients prevailed (54 vs 21, M/F ratio of 2.57), suggesting a gender difference in the incidence of IVT. IVT occurred mainly in young and middle-age patients. Most RVOT-IVT occurred in the third to fourth decade of life (mean 36-/+12 years), and LV-IVT occurred at a younger age than did RVOT-IVT (mean 26-/+15 years, P<0.01). Twelve-lead ECGs revealed left bundle branch block morphology in RVOT-IVT, and most of them presented with frequent premature ventricular contraction and/or non-sustained ventricular tachycardia. All the RVOT-IVT patients were successfully ablated by radiofrequency energy in pace mapping. LV-IVT patients with right bundle branch block morphology presented sustained ventricular tachycardia for most of the time, and 97% of the patients were successfully managed with radiofrequency ablation in activation mapping. Four IVT patients were characterized by atypical bundle branch block, an inferior axis, and an R/S ratio >1 in lead V3 or V2, and their tachycardia was ablated successfully in the left sinus of Valsalva using pace mapping. Radiofrequency ablation is currently an effective procedure for IVT management.</p>