Antioxidant Activity of Aqueous Extract of Leaves and Seeds of Datura metel (Solanaceae) in Frog's Heart Failure Model.

Objective: The aim of this work was to evaluate the antioxidant potential of Datura metel. Materials and Methods: Heart failure was induced in the frog's heart by continuous perfusion of hydrogen peroxide. Survival time and some heart tissue parameters of oxidative stress were recorded in the presence of aqueous extracts of the leaves and seeds of Datura metel. Ascorbic acid was used as a reference drug. Results: H2O2-enriched Ringer's solution inhibited the negative inotropic and chronotropic effects of acetylcholine, indicating the desensibilization of muscarinic receptors due to H2O2-induced oxidative stress. These hearts had a relatively short survival time (14 minutes). In the presence of the aqueous extract of the leaves and seeds of Datura metel (1.5 and 2.5 mg/mL), the time necessary to cause the cardiac arrest was extended to 35 and 37 minutes, respectively, versus 29 minutes for ascorbic acid and 14 minutes for H2O2. Furthermore, antioxidant parameters (MDA, SOD, and CAT) were significantly improved in plant extract-treated hearts, compared to peroxidized hearts. Conclusion: Aqueous extract of the leaves and seeds of D. metel can extend heart survival time through antioxidant mechanisms.

The pharmaco-invasive approach to STEMI: when should fibrinolytic-treated patients go to the "cath lab"?

Although primary percutaneous coronary intervention (PCI) in clinical trials has lower rates of reinfarction, stroke and mortality than fibrinolytic therapy, because of system delays in routine practice, field triage and prehospital administration of fibrinolytic therapy may lead to similar clinical outcomes, especially in those patients who present in the first 2 h after symptom onset. Necessary for these outcomes is the liberal use of both rescue PCI and in-hospital revascularisation. Non-invasive prediction of failed reperfusion may be enhanced by the use of ST recovery, patient characteristics and troponin T levels, measured by point-of-care assays. This review focuses on the timing of, and indications for, an invasive strategy after fibrinolytic therapy, including that for failed pharmacological reperfusion.

The pharmaco-invasive approach to STEMI: when should fibrinolytic-treated patients go to the "cath lab"?

Although primary percutaneous coronary intervention (PCI) in clinical trials has lower rates of reinfarction, stroke and mortality than fibrinolytic therapy, because of system delays in routine practice, field triage and prehospital administration of fibrinolytic therapy may lead to similar clinical outcomes, especially in those patients who present in the first 2 h after symptom onset. Necessary for these outcomes is the liberal use of both rescue PCI and in-hospital revascularisation. Non-invasive prediction of failed reperfusion may be enhanced by the use of ST recovery, patient characteristics and troponin T levels, measured by point-of-care assays. This review focuses on the timing of, and indications for, an invasive strategy after fibrinolytic therapy, including that for failed pharmacological reperfusion.

Variations in the use of emergency PCI for the treatment of re-infarction following intravenous fibrinolytic therapy: impact on outcomes in HERO-2.

BACKGROUND: Patients who suffer re-infarction during initial hospitalization for ST-elevation myocardial infarction (STEMI) have decreased survival compared to patients without re-infarction, so treatment of re-infarction may influence survival. METHODS AND RESULTS: To determine whether the utilization of reperfusion therapies varied within 12 h of re-infarction and was associated with 30-day mortality, we studied 552 patients with re-infarction of 17,073 patients with STEMI enrolled in HERO-2 in five regions (Russia, Eastern Europe, Western Countries, Asia, and Latin America). Patients presenting within 6 h of symptom-onset were randomized to receive either bivalirudin or unfractionated heparin intravenously just prior to streptokinase. Re-infarction occurred in 2.8 and 3.6% of bivalirudin and heparin treated patients, respectively (P = 0.004), but treatment assignment did not influence mortality after re-infarction. Patients with re-infarction had a higher 30-day mortality than those without re-infarction (24 vs. 10%; P < 0.001 by Cox model). Within 12 h of re-infarction, fibrinolytic therapy was administered to 12.0 and 8.2% underwent percutaneous coronary intervention (PCI); these two treatments were more frequently utilized in patients from Western countries (n = 112), compared to patients from other countries (n = 440) (34.8 and 16.1% compared to 6.1 and 6.1%, respectively, P < 0.001). Mortality was 15% in patients receiving reperfusion therapy for re-infarction and 27% for those with conservative management, hazard ratio (HR) 0.53 (95% CI 0.32-0.88), P = 0.01. In multiple Cox regression analysis which included adjustment for clinical variables and randomized treatment assignment, 30-day mortality after re-infarction varied by region (highest Latin America 29%, lowest Western countries 15%; P = 0.01). Other independent prognostic factors included age, time from randomization to re-infarction, and Killip class at randomization. The HR for PCI treatment of re-infarction was 0.18 [(95% CI 0.04-0.76), P = 0.02] in analyses which excluded deaths within 12 h. CONCLUSION: Treatment of re-infarction with reperfusion therapies was markedly under-utilized, especially in non-western countries. PCI for re-infarction, in particular, was associated with a lower 30-day mortality, which may reflect both patient selection and effects of treatment.

Thrombotic risk in patients with aortic bioprostheses.

Thrombosis of Mosaic aortic valve bioprostheses occurring at more than one month after surgery occurs in 0.8% (95% CI 0.33-1.67%) of patients. In the two cases reported here, each patient had risk factors for thrombus formation, namely severe left ventricular impairment in one patient, while the other patient was heterozygous for prothrombin variant G20210A. The cases were treated successfully, by thrombolytic therapy with streptokinase in the first case, and by repeat aortic valve replacement in the second case. Thrombosis of bioprosthetic valves in the aortic position is rare, and a period of anticoagulation postoperatively does not invariably protect against this serious complication. In conclusion, patients with risk factors for thrombus formation should be considered for long-term anticoagulation.

Community acquired staphylococcal pulmonary valve endocarditis in non-drug users: case report and review of the literature.

Right sided endocarditis usually involves the tricuspid valve, predominantly in intravenous drug users. It is also occasionally acquired in hospital as a result of contaminated intravascular devices. Isolated infection of the pulmonary valve is rarely seen. A case of community acquired Staphylococcus aureus pulmonary valve endocarditis that caused diagnostic confusion is reported. This infection occurred in a patient with no history of intravenous drug abuse and a previously structurally normal heart.

Calcium paradox in guinea-pig ventricular myocytes.

Measurement of the release of lactate dehydrogenase (LDH), the development of contracture and the exclusion of the dye Trypan Blue were made in isolated guinea-pig ventricular myocytes subjected to conditions that evoke a calcium paradox in intact heart. Incubation at 25 degrees C reduced the release of LDH associated with mechanical manipulation of the myocytes so that during prolonged incubation in media free of Ca2+ and Mg2+ ions at 25 degrees C little release of LDH occurred. A significant release of LDH into the incubation media was provoked on repletion of the divalent cations. This release was accompanied by a marked decrease in the percentage of rod-shaped myocytes and their ability to exclude Trypan Blue. The results provide evidence for the existence of the calcium paradox in isolated guinea-pig ventricular myocytes as originally defined.