OBJECTIVETo evaluate the effects of antiarrhythmic peptide (AAP10) on ventricular arrhythmias in rabbits with healed myocardial infarction (OMI).

METHODSThirty rabbits were randomly divided into three groups (n = 10 each): Sham group, left thoracotomy was performed without coronary ligation; OMI group and OMI + AAP10 group, the circumflex coronaries were ligated. Three months post operation, the electrophysiological and antiarrhythmic effects of AAP10 were assessed in the arterially perfused rabbit left ventricular wedge preparation. Sham and OMI group were perfused with Tyrode's solution and OMI + AAP10 group was perfused with Tyrode's solution + AAP10 (80 nmol/L). Transmembrane action potentials were recorded simultaneously from endocardium and epicardium together with a transmural ECG by use of 2 separate intracellular floating microelectrodes. The stimulus-response-interval (SRI) of the epicardium and the incidence of ventricular tachycardia (VT) were observed. Whole heart and left ventricular weights, the left ventricular thickness at infarct border zone were measured.

RESULTSWhole heart and left ventricular weights as well as the left ventricular thickness at the infarct border zone significantly increased post infarction. VT was induced in 8 out of 10 rabbits in OMI group and in 2 out of 10 rabbits in OMI + AAP10 group (P < 0.05). SRI was also significantly shortened in OMI + AAP10 group compared to OMI group [SRI-1: (20.59 +/- 0.79) ms vs. (28.71 +/- 0.55) ms; SRI-2: (30.42 +/- 0.74) ms vs. (38.67 +/- 0.49) ms, all P < 0.01]. However, the action potential morphology and duration were similar between OMI and OMI + AAP10 groups.

CONCLUSIONThe antiarrhythmic peptide (AAP10) can increase gap junctional intercellular conductance without affecting the action potential morphology and duration and decrease the incidence of inducible ventricular tachycardia.

Animals ; Arrhythmias, Cardiac ; etiology ; prevention & control ; Male ; Myocardial Infarction ; complications ; physiopathology ; Oligopeptides ; pharmacology ; Rabbits ; Random Allocation

BACKGROUNDPlasma transfusion is a common clinical practice. Remote ischemic preconditioning (RIPC) protects organs against ischemia-reperfusion (IR) injury. Whether preconditioned plasma (PP), collected at late phase after RIPC, could protect organs against IR injury in vivo is unknown. This study explored whether transfusion of PP could reduce myocardial infarct size (IS) after IR in rat in vivo.

METHODSEighty Lewis rats were randomized to eight groups (n = 10 for each group). Two groups of plasma donor rats donated plasma at 48 h after transient limb ischemia (PP) or control protocol (nonpreconditioned plasma [NPP]). Six groups of recipient rats received normal saline (NS; NS-IR 1, and NS-IR 24 groups), NPP (NPP-IR 1 and NPP-IR 24 groups), or PP (PP-IR 1 and PP-IR 24 groups) at one or 24 h before myocardial IR. Myocardial IR consisted of 30-min left anterior descending (LAD) coronary artery occlusion and 180-min reperfusion. The area at risk (AAR) and infarct area were determined by double-staining with Evans blue and triphenyltetrazolium chloride. IS was calculated by infarct area divided by AAR. This was a 3 × 2 factorial design study, and factorial analysis was used to evaluate the data. If an interaction between the fluid and transfusion time existed, one-way analysis of variance with Bonferroni correction for multiple comparisons was used to analyze the single effects of fluid type when the transfusion time was fixed.

RESULTSIS in the NPP-IR 1 and PP-IR 1 groups was smaller than in the NS-IR 1 group (F = 6.838, P = 0.005; NPP-IR 1: 57 ± 8% vs. NS-IR1: 68 ± 6%, t = 2.843, P = 0.020; PP-IR 1: 56 ± 8% vs. NS-IR 1: 68 ± 6%, t = 3.102, P = 0.009), but no significant difference was detected between the NPP-IR 1 and PP-IR 1 groups (57 ± 8% vs. 56 ± 8%, t = 0.069, P = 1.000). IS in the NPP-IR 24 and PP-IR 24 groups was smaller than in the NS-IR 24 group (F = 24.796, P< 0.001; NPP-IR 24: 56% ± 7% vs. NS-IR 24: 68 ± 7%, t = 3.102, P = 0.026; PP-IR 24: 40 ± 9% vs. NS-IR 24: 68 ± 7%, t = 7.237, P< 0.001); IS in the PP-IR 24 group was smaller than in the NPP-IR 24 group (40 ± 9% vs. 56 ± 7%, t = 4.135, P = 0.002).

CONCLUSIONTransfusion of PP collected at late phase after remote ischemic preconditioning could reduce IS, suggesting that late-phase cardioprotection was transferable in vivo.

Animals ; Blood Component Transfusion ; methods ; Ischemic Preconditioning, Myocardial ; methods ; Male ; Myocardial Infarction ; etiology ; prevention & control ; Myocardial Reperfusion Injury ; complications ; Plasma ; Rats

To explore the protective effects of right coronary artery ischemic preconditioning and post-conditioning on myocardial ischemia reperfusion injury in rabbit heart.
 Methods: A total of 30 rabbits were randomly divided into 4 groups: a control group (n=7), an ischemia reperfusion group (IR group, n=8), an ischemic preconditioning group (IPC group, n=8) and an ischemic post-conditioning group (IPO group, n=7). Venous blood samples were taken at pre-operation, 1 and 6 h post-operation, and the concentration of serum creatine kinase isoenzyme (CK-MB) and cardiac troponin-T (cTn-T) were measured. The infarct area of cardiac muscle was calculated.
 Results: Compared with the IR group, the levels of CK-MB and cTn-T at 1 and 6 h post-operation in the IPC group and the IPO group were reduced (all P<0.05). Compared with the IR group, the infarct size in the IPC group and the IPO group was significantly decreased, with significant difference (both P<0.05) .
 Conclusion: Right coronary artery ischemic preconditioning and post-conditioning exert significant protective effects on the myocardial ischemia reperfusion injury in New Zealand rabbits.
Animals ; Coronary Vessels ; Creatine Kinase, MB Form ; blood ; Heart ; Ischemia ; Ischemic Postconditioning ; Ischemic Preconditioning ; Ischemic Preconditioning, Myocardial ; Myocardial Infarction ; etiology ; pathology ; physiopathology ; prevention & control ; Myocardial Ischemia ; complications ; therapy ; Myocardial Reperfusion Injury ; prevention & control ; Myocardium ; Rabbits ; Troponin T ; blood

Myocardial ischemic preconditioning and postconditioning can reduce myocardial infarct size, improve myocardial contractility, protect coronary endothelial and myocardial cell ultrastructure, as well as reduce the incidence of arrhythmias. Clinical practice has confirmed the safety and efficacy of these two methods of myocardial protection. This paper reviewed about ischemic preconditioning and postconditioning protection mechanisms in myocardial ischemia reperfusion injury and clinical research literatures in recent years, to provide a theoretical basis for finding new treatment strategies on the prevention and treatment of ischemic cardiomyopathy.
Animals ; Humans ; Ischemic Postconditioning ; methods ; Ischemic Preconditioning, Myocardial ; methods ; Myocardial Infarction ; therapy ; Myocardial Ischemia ; therapy ; Myocardial Reperfusion ; adverse effects ; Myocardial Reperfusion Injury ; etiology ; prevention & control ; Receptors, G-Protein-Coupled ; agonists ; Signal Transduction

This study was conducted to evaluate the effect of a teaching program on patients with myocardial infarction. Forty-five patients were randomly selected 22 were assigned to a teaching group and 23 to a control group. An individualized teaching program was delivered to the teaching group during the hospitalization period. It covered aspects such as: the characteristics of heart disease, the anatomy and physiology of the heart, risk factors of atherosclerosis, medication and diet and exercise therapy. When these subjects were discharged to their homes, they received regular supportive care via telephone or mail for 12 weeks. Atherosclerotic risk factors, including, smoking, exercise, blood lipid profile and BMI were measured before and after the teaching program. Post-testing revealed that the numbers of those who exercised and the number of non-smokers were significantly higher in the teaching group than in the control group. Increased HDL cholesterol (High-Density Lipoprotein cholesterol) was significantly greater in the teaching group than in the control group. The above findings suggest that this individualized teaching program might be helpful at reducing the risk factors of atherosclerosis in myocardial infarction patients.
Adult ; Aged ; Arteriosclerosis/etiology/*prevention & control ; Comparative Study ; Exercise ; Female ; Human ; Lipids/blood ; Male ; Middle Age ; Myocardial Infarction/*prevention & control ; *Patient Education ; Risk Factors ; Smoking

BACKGROUNDThis study was designed to evaluate the relationship between high-density lipoprotein cholesterol (HDL-C) level and acute myocardial infarction (AMI) and coronary heart disease (CHD) death and to explore the protective effect of HDL against CHD in the elderly Chinese.

METHODSStarted from 1986, 1211 retirees (92% males) were enrolled consecutively and studied prospectively. The average starting age was 70 +/- 9 years, and that at the end of the study was 80 +/- 9 years. During the follow-up study, all the participants received yearly physical examination and blood chemistry survey from 1986 - 2000. The average duration of the follow up study was 11.2 years. The end point of this study was either attacks of AMI or death due to CHD and other causes. CHD risk factors were screened by logistic regression analysis. According to their HDL-C levels, cases were divided into low (< 1.03 mmol/L), medium (or normal, 1.03 - 1.56 mmol/L) and high (> 1.56 mmol/L) level groups, the differences in incidence of AMI and CHD death in each group were analyzed.

RESULTSThe cumulative attacks of acute coronary syndrome (mostly AMI) were 214 cases, including 89 cases of coronary death and 308 death caused by other diseases during the follow up study. AMI occurrence and CHD death in normal HDL-C group were lower than those in the low HDL-C group by 40% and 53%; and those in the high HDL-C group were lower than in the normal group by 56% and 50%, respectively. Statistical analysis on normal lipid cases (411 cases, total cholesterol < 5.17 mmol/L, triglyceride < 1.69 mmol/L) revealed that the cases at low HDL-C level had similar rates of AMI events and CHD mortality as those of the entire group (including hyperlipidemia); however, AMI attacks and CHD deaths decreased significantly at the normal and high HDL-C levels. The results demonstrated that the protective effect of HDL against coronary artery disease is more prominent in people with low lipid level.

CONCLUSIONLow HDL is an important independent risk factor for AMI attacks and CHD death in the elderly; high HDL has significant protective effect against coronary artery disease.

Aged ; Aged, 80 and over ; Cholesterol, HDL ; blood ; Cholesterol, LDL ; blood ; Coronary Disease ; blood ; etiology ; prevention & control ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; etiology ; Risk Factors

OBJECTIVETo study the preventive effect of Shenfu Injection (SI) in different dosage on occurrence of heart failure in patients of acute myocardial infarction (MI) with elevated ST segment.

METHODSNinety-seven patients of MI were divided into 3 groups, all were treated with conventional therapy, but to the SI treated groups, intravenous injection of low (0.3 ml/kg) or high dose (0.6 ml/kg) of SI were given once a day additionally. After 14 days' treatment, the incidence of heart failure and its severity were observed and evaluated with Killip grading.

RESULTSThere was no significant difference in the incidence of heart failure among the 3 groups, but the severity of heart failure in the SI treated groups was remarkably milder than that in the control group, and the high dose SI showed the effect superior to that of low dose SI.

CONCLUSIONBased on the conventional treatment, Shenfu Injection is helpful for alleviating the severity of heart failure.

Adult ; Aged ; Drugs, Chinese Herbal ; administration & dosage ; Electrocardiography ; Female ; Heart Failure ; etiology ; prevention & control ; Humans ; Injections, Intravenous ; Male ; Middle Aged ; Myocardial Infarction ; complications ; drug therapy ; physiopathology ; Phytotherapy

BACKGROUND/AIMS: This meta-analysis compared the effects of amlodipine besylate, a charged dihydropyridine-type calcium channel blocker (CCB), with other non-CCB antihypertensive therapies regarding the cardiovascular outcome. METHODS: Data from seven long-term outcome trials comparing the cardiovascular outcomes of an amlodipine-based regimen with other active regimens were pooled and analyzed. RESULTS: The risk of myocardial infarction was significantly decreased with an amlodipine-based regimen compared with a non-CCB-based regimen (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.84 to 0.99; p = 0.03). The risk of stroke was also significantly decreased (OR, 0.84; 95% CI, 0.79 to 0.90; p < 0.00001). The risk of heart failure increased slightly with marginal significance for an amlodipine-based regimen compared with a non-CCB-based regimen (OR, 1.14; 95% CI, 0.98 to 1.31; p = 0.08). However, when compared overall with beta-blockers and diuretics, amlodipine showed a comparable risk. Amlodipine-based regimens demonstrated a 10% risk reduction in overall cardiovascular events (OR, 0.90; 95% CI, 0.82 to 0.99; p = 0.02) and total mortality (OR, 0.95; 95% CI, 0.91 to 0.99; p = 0.01). CONCLUSIONS: Amlodipine reduced the risk of total cardiovascular events as well as all-cause mortality compared with non-CCB-based regimens, indicating its benefit for high-risk cardiac patients.
Amlodipine/*therapeutic use ; Antihypertensive Agents/*therapeutic use ; Blood Pressure/*drug effects ; Calcium Channel Blockers/*therapeutic use ; Chi-Square Distribution ; Clinical Trials as Topic ; Heart Failure/etiology/mortality/*prevention & control ; Humans ; Hypertension/complications/diagnosis/*drug therapy/mortality/physiopathology ; Myocardial Infarction/etiology/mortality/*prevention & control ; Odds Ratio ; Risk Factors ; Stroke/etiology/mortality/*prevention & control ; Treatment Outcome

We performed a prospective cohort trial on 220 patients undergoing elective off-pump coronary artery bypass surgery and taking aspirin to evaluate the effect of aspirin resistance on myocardial injury. The patients were divided into aspirin responders and aspirin non-responders by the value of the aspirin reaction units obtained preoperatively using the VerifyNow(TM) Aspirin Assay. The serum levels of troponin I were measured before surgery and 1, 6, 24, 48 and 72 hr after surgery. In-hospital major adverse cardiac and cerebrovascular events, graft occlusion, the postoperative blood loss and reexploration for bleeding were recorded. Of the 220 patients, 181 aspirin responders (82.3%) and 39 aspirin non-responders (17.7%) were defined. There were no significant differences in troponin I levels (ng/mL) between aspirin responders and aspirin non-responders: preoperative (0.04 +/- 0.08 vs 0.03 +/- 0.06; P = 0.56), postoperative 1 hr (0.72 +/- 0.87 vs 0.86 +/- 1.10; P = 0.54), 6 hr (2.92 +/- 8.76 vs 1.50 +/- 2.40; P = 0.94), 24 hr (4.16 +/- 13.44 vs 1.25 +/- 1.95; P = 0.52), 48 hr (2.15 +/- 7.06 vs 0.65 +/- 0.95; P = 0.64) and 72 hr (1.20 +/- 4.63 vs 0.38 +/- 0.56; P = 0.47). Moreover, no significant differences were observed with regard to in-hospital outcomes. In conclusion, preoperative aspirin resistance does not increase myocardial injury in patients undergoing off-pump coronary artery bypass surgery. Postoperative dual antiplatelet therapy might have protected aspirin resistant patients.
Aged ; Aspirin/*administration & dosage ; Cohort Studies ; Coronary Artery Bypass, Off-Pump/*adverse effects ; Coronary Disease/*surgery ; Drug Resistance ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction/etiology ; Myocardial Reperfusion Injury/*prevention & control ; Platelet Aggregation Inhibitors/*administration & dosage ; Postoperative Hemorrhage/etiology ; Preoperative Care/methods ; Prospective Studies ; Stroke/etiology ; Troponin I/blood

PURPOSE: This study compared the impact of paclitaxel-coated balloons (PCB) or drug eluting stents (DES) on peri-procedural myocardial infarction (PMI) on de novo coronary lesion in stable patients. MATERIALS AND METHODS: In this observational study, we compared the incidence of PMI amongst patients with single vessel de novo coronary lesions who underwent treatment with a PCB or DES. Propensity score-matching analysis was used to assemble a cohort of patients with similar baseline characteristics. PMI was classified as myocardial infarction occurring within 48 hours after percutaneous coronary intervention with a threshold of 5 x the 99th percentile upper reference limit of normal for creatine kinase-myocardial band (CK-MB) or troponin T (TnT). RESULTS: One hundred four patients (52 receiving PCB and 52 receiving DES) were enrolled in this study. The peak mean values of CK-MB and TnT were significantly higher in the DES group. There was a significantly higher rate of PMI in the DES group (23.1% vs. 1.9%, p=0.002). Total occlusion of the side-branch occurred in two patients treated with DES, while no patients treated with PCB. In multivariable analysis, DES was the only independent predictor of PMI compared with PCB (odds ratio 42.85, 95% confidence interval: 3.44–533.87, p=0.004). CONCLUSION: Treatment with a PCB on de novo coronary lesion might be associated with a significant reduction in the risk of PMI compared to DES.
Aged ; Creatine Kinase, MB Form/analysis ; *Drug-Eluting Stents ; Female ; Humans ; Incidence ; Kaplan-Meier Estimate ; Middle Aged ; Myocardial Infarction/enzymology/epidemiology/etiology/*prevention & control ; Odds Ratio ; Paclitaxel/*therapeutic use ; Percutaneous Coronary Intervention/*adverse effects ; Propensity Score ; Time Factors ; Treatment Outcome