Clinical assessment of Tpeak-end interval for prediction of myocardial infarction / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of Tpeak-end interval (Tpe) in predicting myocardial infarction (MI).</p><p><b>METHODS</b>Tpe and Tpeak-end internal after correcting the heart rate (TpeRR) were measured and analyzed in 234 MI patients, who were followed-up for an average of 32 ± 10 months.</p><p><b>RESULTS</b>Clinical events occurred in 45 (19.2%) patients at the end TpeRR of the follow-up. Tpe and of the patients with clinical events were significantly higher than those in patients without the clinical events (P < 0.001). The incidence of clinical events in patients with Tpe > 140 ms were significantly higher than that in patients with Tpe ≤ 140 ms by Kaplan-Meier analysis (P < 0.001). With clinical event as the end point, the proportional hazards rate was 2.48 in univariate COX analysis (P < 0.01). After controlling for risk factors, the hazards rate was 2.66 by multvariate COX regression (P < 0.01).</p><p><b>CONCLUSION</b>Tpe is positively correlated to the prognosis of MI and serves as an new index for predicting the clinical events in MI patients.</p>

Relationship between Tpeak-Tend interval and coronary artery stenosis and effects of percutaneous transluminal coronary angioplasty on Tpeak-Tend / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the relationship between Tpeak-Tend interval (Tpe) and the extent and severity of coronary artery stenosis, and evaluate the effect of percutaneous transluminal coronary angioplasty and stent implantation (PCI) on Tpe in the patients with coronary heart disease (CHD).</p><p><b>METHODS</b>The ECG data were collected from 187 CHD patients undergoing coronary angiography and PCI to evaluate the extend and severity of coronary artery stenosis before and after the interventions.</p><p><b>RESULTS</b>The Tpe of patients with severe stenosis increased significantly as compared with that in patients with moderate stenosis (138.9-/+16.2 ms vs 116.5-/+13.7 ms, P<0.05), and a significant difference was also noted between the moderate stenosis and mild stenosis (86.4-/+12.9 ms) groups (P<0.05). The Tpe decreased significantly in the patients in the order of multi-vessel involvement (140.7-/+17.8 ms), double vessel involvement (118.6-/+14.9 ms), singly vessel involvement (100.5-/+13.2 ms), and stenosis-free (84.3-/+12.4 ms) groups (P<0.05). Tpe was correlated to the extent and severity of coronary artery stenosis (r>0.4). In patients with severe stenosis, the Tpe was significantly reduced at 1 h, 24 h, and 1 week after PCI (115.8-/+14.5, 92.7-/+12.9, and 88.2-/+11.3 ms, respectively, P<0.05).</p><p><b>CONCLUSION</b>The Tpe can reflect the severity and range of coronary artery stenosis, which can be reduced by PCI. Tpe can be a new index for evaluating myocardial ischemia in CHD patients.</p>

Role of matrix metalloproteinase and tissue inhibitor of metalloproteinase in atrial structural remodeling in patients with atrial fibrillation / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relationship between atrial structural remodeling and the expressions of matrix metalloproteinase (MMPs) and their tissue inhibitors (TIMPs) in atrial fibrillation (AF).</p><p><b>METHODS</b>Biopsy samples of the right atrial appendages were collected from 20 patients with sinus rhythm and 30 with AF undergoing heart valve replacement surgery for rheumatic heart diseases. All the patients received echocardiographic examination preoperatively. MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 protein expressions were detected by immunohistochemistry and RT-PCR.</p><p><b>RESULTS</b>Compared with those in patients with sinus rhythm, the AF patients had significantly increased left and right atrial diameters and mRNA levels of MMP-3, -7, -9 and TIMP-1, -2, -3, -4 (P<0.01). MMP-1 expression also showed an increase in AF patients, but the difference was no statistically significant from that in patients with sinus rhythm.</p><p><b>CONCLUSION</b>The expressions of MMP-1, -3, -7, -9 and TIMP-1, -2, -3, -4 increase in fibrillating atrial tissue, which may contribute to atrial structural remodeling and atrial dilatation in AF patients.</p>

Comparison of right atrial matrix metalloproteinase expression between patients with unstable angina and myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare right atrial structural remodeling and the expression of matrix metalloproteinase (MMP) and tissue inhibitors (TIMP) between patients with unstable angina (UA) and myocardial infarction (MI).</p><p><b>METHODS</b>Right atrial appendages were obtained from 18 patients with UA and 22 patients with MI undergoing coronary artery bypass grafting (CABG) operations. MMP-1, -3, -7, -9 and TIMP-1 protein expressions were detected by immunohistochemistry and RT-PCR. Echocardiography was performed before CABG.</p><p><b>RESULTS</b>The left and right atrial diameter, left ventricular diameter and mRNA levels of MMP-3, MMP-9 and TIMP-1 were significantly higher in MI group than those in UA group [LAD: (40.8 +/- 4.2) mm vs. (33.1 +/- 5.1) mm, P < 0.01; RAD: (44.1 +/- 6.8) mm vs. (28.8 +/- 6.0) mm, P < 0.01; LVEDD: (48.9 +/- 6.0) mm vs. (39.7 +/- 7.1) mm, P < 0.05; MMP-3: 0.39 +/- 0.18 vs. 0.28 +/- 0.07, P < 0.05; MMP-9: 0.81 +/- 0.21 vs. 0.55 +/- 0.20, P < 0.01; TIMP-1: 1.79 +/- 0.89 vs. 0.94 +/- 0.47, P < 0.01]. MMP-1, MMP-7 levels were similar between the 2 groups (MMP-1: 0.14 +/- 0.06 vs. 0.10 +/- 0.08, P > 0.05; MMP-7: 0.25 +/- 0.05 vs. 0.23 +/- 0.06, P > 0.05).</p><p><b>CONCLUSION</b>Right atrial up-regulation of MMP-3, MMP-9 and TIMP-1 levels may contribute to the right atrial structural remodeling in MI patients.</p>

Correlation of heart rate turbulence to coronary lesions and its changes following percutaneous transluminal coronary angioplasty / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the correlation between heart rate turbulence (HRT) and coronary lesion and the effects of percutaneous transluminal coronary angioplasty (PTCA) on HRT.</p><p><b>METHODS</b>This study involved 150 patients undergoing 24-hour ambulatory electrocardiography (AECG) and elective coronary angiography (CAG). AECG was monitored on the first day and 7 days after PTCA in 108 patients with positive CAG findings, and the variation of HRT and cardiac functions were observed. The turbulence onset (TO), turbulence slope (TS) and turbulence timing (TT) of each section of HRT were calculated, analyzed and compared.</p><p><b>RESULTS</b>The values of TO and TT were significantly higher and TS significantly lower in CAG-positive group than in CAG-negative group (P<0.05 or 0.001). Significant difference was found in TO, TS and TT between patients with single and multiple coronary lesions (P<0.05 and 0.001). The values of TO, TS and TT on the first day after PTCA improved significantly in comparison with the those before PTCA in patients with single and multiple coronary lesions (P<0.001). Postoperative follow-up of the patients revealed obviously attenuated HRT in patients with left cardiac insufficiency compared with the patients with normal cardiac function (P<0.05).</p><p><b>CONCLUSION</b>HRT is correlated to the severity of the coronary lesions and shows significant improvement after PTCA. Cardiac function insufficiency is an important factor affecting the HRT attenuation.</p>

Efficacy and safety of segmental pulmonary vein isolation and circumferential pulmonary vein isolation in patients with atrial fibrillation: a comparative study / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the efficacy and safety of segmental pulmonary vein isolation (SPVI) and circumferential pulmonary vein isolation (CPVI) guided by EnSite NavX system in patients with atrial fibrillation (AF).</p><p><b>METHODS</b>Eighty-five patients with paroxysmal AF and persistent AF were enrolled in this study. Forty patients (30 with paroxysmal AF and 10 with persistent AF) underwent SPVI procedure, and 45 (31 with paroxysmal AF and 14 with persistent AF) underwent CPVA guided by EnSite NavX three-dimensional electrophysiological mapping system. All the patients were followed up for over six months.</p><p><b>RESULTS</b>The success rate was 65% in the SPVI group and 84.4% in the CPVI group (P=0.0332), with incidence of major complications of 17.5% and 6.7%, respectively (P=0.0845). In the SPVI group, 12.5% patients had pulmonary vein stenosis after the operation, which occurred in none of the patients in the CPVI group (P=0.0312). The total procedure time was 200.4+/-37.0 min in the SPVI group, significantly shorter than that in the CPVI group (226.5+/-26.1 min, P=0.002). The fluoroscopy time in the SPVI group was obviously longer than that in the CPVI group (54.7+/-9.7 vs 27.1+/-3.1 min, P<0.001).</p><p><b>CONCLUSIONS</b>CPVI guided by EnSite NavX system is more effective than SPVI for treatment of atrial fibrillation with significantly shortened fluoroscopy time but prolonged procedure time. The two procedures results in comparable incidences of major complications, but CPVI is associated with reduced rate of pulmonary vein stenosis in comparison with SPVI.</p>

Therapeutical efficacy of routine intra-aortic balloon pump support in patients with high-risk acute myocardial infarction undergoing percutaneous coronary intervention / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of routine intra-aortic balloon pump (IABP) support in patients with high-risk acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI).</p><p><b>METHODS</b>The clinical data of 41 patients with high-risk AMI undergoing emergency PCI with routine IABP support were retrospectively reviewed, and 38 patients paired with the former group receiving emergency PCI for high-risk AMI without IABP support at the same time were included as the control group. Thirty days after the operation, the two groups were compared for myocardial ischemic events, left ventricular function and major adverse cardiac events (MACE).</p><p><b>RESULTS</b>Patients receiving IABP support had a significantly lower incidence of myocardial ischemic events than those without IABP (4.9% vs 15.8%, P<0.05), and showed greater improvement in the left ventricular function. Significant differences were also observed in the mortality rate, incidence of reinfarction and revascularization rate between the two groups, but not in the rate of MACE.</p><p><b>CONCLUSION</b>Patients undergoing PCI for high-risk acute AMI can benefit from routine IABP support in terms of improvement of left ventricular function and reduce myocardial ischemic events and the rate of MACE. These results, however, still await further confirmation by large-scale clinical trials.</p>

Relation of plasma brain natriuretic peptide to serum creatine kinase MB level in patients with acute myocardial infarction following primary percutaneous coronary intervention / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the relation between plasma brain natriuretic peptide (BNP) and serum creatine kinase MB (CK-MB) level in patients with acute myocardial infarction (AMI) following primary percutaneous coronary intervention (PCI).</p><p><b>METHODS</b>Sixty-three consecutive patients with AMI were divided into two groups according to the timing of PCI, namely direct PCI and indirect PCI groups. Plasma BNP levels were measured in all patients on admission and at 4, 24 and 48 h after admission. The CK-MB level was measured every 3 h on the first day of hospitalization, every 6 h on the second day and every 12 h on the third day.</p><p><b>RESULTS</b>BNP level increased gradually following admission and began to decrease 48 h after admission in the two groups of patients. The peak BNP level occurred at 24 h after admission, and the BNP levels in patients of indirect PCI group were significantly higher than that of direct PCI group at 4, 24 and 48 h after admission. The peak CK-MB level of the direct PCI group occurred significantly earlier than that of the indirect group.</p><p><b>CONCLUSION</b>Plasma BNP level may serve as an important objective indicator for recanalization of the infarct-related arteries following PCI in the early stage of AMI, which can help in the decision on clinical treatment plans for AMI.</p>