Category Archives: Stenosis

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Conclusion

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: ConclusionWe could not completely exclude the potential impact of heparinized saline solution on platelet P-selectin expression before valvuloplasty. However, in our previous study, we found that the fraction of platelets expressing P-selectin in the femoral venous or arterial blood obtained through introducer sheaths immediately after puncture without heparinized saline solution flushed into patients did not differ from that in the right atrial blood obtained after a small amount of heparinized saline solution was flushed through introducer sheaths into patients. Therefore, the use of heparinized saline solution should not be a concern in this study. Fifth, as the blood samples were drawn through femoral sheaths before valvuloplasty and through the antecubital vein using a syringe with a sterile 22-gauge needle during follow-up studies, we could not completely exclude the fact that different sampling techniques might affect P-selection expression in platelets. Theoretically, small needles might increase P-selectin expression in platelets. However, this did not occur in this study as increased platelet activation fell significantly after PTMV at follow-up visits. Finally, as the number of patients having a history of systemic arterial thromboembolism was small, it was not our aim to study the difference in platelet activity between patients with and without a history of systemic arterial thromboembolism. lumigan eye drops

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Clinical Implication

A large body of epidemiologic data indicates that patients with rheumatic MS, and in particular those with atrial fibrillation or left atrial spontaneous echo contrast, are at risk of developing left atrial throm-bi. Coagulation activity has been demonstrated’ to be increased in patients with MS, even in the absence of echocardiographic visualized thrombi. Chiang and associates have demonstrated that PTMV is a negative predictor of systemic embolism in patients with rheumatic MS who are experiencing atrial fibrillation. One possible mechanism is the amelioration of regional left atrial hypercoagulability by PTMV. In this study, we demonstrated that the fraction of platelets expressing P-selectin in the peripheral venous blood obtained before PTMV fell significantly after PTMV, and that the more gain there was in the mitral valve area, the more decrease there was in the fraction of peripheral venous platelets expressing P-selectin after PTMV. Accordingly, we proposed that the amelioration of increased platelets activity by PTMV might contribute to the decreased incidence of systemic embolism by PTMV in patients with MS.

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Discussion

4The present study, in which we examined platelet activation in patients with symptomatic rheumatic MS undergoing PTMV by measuring unstimulated platelet P-selectin expression in the peripheral venous blood samples, produced two major findings. First, the fraction of unstimulated platelets expressing P-selectin in the peripheral venous blood obtained before PTMV fell significantly after PTMV. Second, with the area of mitral valve increasing significantly after PTMV, there was a significantly direct relationship between the magnitude of the increase in mitral valve area after PTMV and the magnitude of decrease in the fraction of unstimulated platelets expressing P-selectin in the peripheral venous blood after PTMV.

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Peripheral Venous Platelet P-Selectin Expression

Peripheral Venous Platelet P-Selectin Expression Before and After PTMV
In a previous study, we demonstrated that the mean fraction of unstimulated platelets expressing P-selectin in the peripheral venous blood of healthy volunteers who were in sinus rhythm (1.7 ± 0.9%) was consistent with that found in another study (2.3%) using 3.8% sodium citrate as the anticoagulant. In addition, the fraction of unstimulated platelets expressing P-selectin among patients with rheumatic MS was significantly higher than that among healthy volunteers who were in sinus rhythm or patients in permanent lone atrial fibrillation. Furthermore, the increased peripheral venous platelet activity of patients with rheumatic MS was evident both in patients who were in sinus rhythm and in those with atrial fibrillation. The platelet activation with respect to P-selectin expression of healthy volunteers in sinus rhythm did not differ from that of patients in permanent lone atrial fibrillation.

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Statistical Analysis

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Statistical AnalysisContinuous variables were described as the mean ± SD. Continuous variables before and after PTMV were compared using the Wilcoxon signed rank test. The fractions of platelets expressing P-selectin in the peripheral venous blood obtained before PTMV, and at the 1-week and 4-week follow-ups after PTMV, were compared using the repeated-measures analysis of variance. The Scheffe test was used for post hoc comparisons. The relationships between platelet P-selectin expression and mitral valve area, left atrial pressure, pulmonary artery pressure, or atrial dimension were performed using the Pearson correlation. Statistical analysis was performed with a statistical software package (SAS for Windows, version 8.02; SAS Institute; Cary, NC). A probability value of < 0.05 was considered to be statistically significant. pilocarpine eye drops

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: CD

Platelet activity was determined with respect to a-granule degranulation (ie, surface expression of P-selectin or CD 62p antigen). Ten-microliter aliquots of platelet-rich plasma were placed in 5-mL polystyrene tubes (Falcon; Becton Dickinson) that contained 90 μL diluted sterile phosphate-buffered solution (pH 7.4; sodium chloride, 137 mmol/L; potassium chloride, 2.7 mmol/L; phosphate buffer, 10 mmol/L) to prevent the aggregation of platelets and 5 μL fluorochrome-labeled antibodies. Fluorescein isothiocyanate-conjugated antibody to glycoprotein IIIa (CD61; Becton Dickinson) was used as an activation-independent marker of platelets. travoprost eye drops

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Valvuloplasty Procedure

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Valvuloplasty ProcedureWarfarin therapy was discontinued for 3 to 4 days before patients underwent PTMV and was administered on the second day after PTMV. Warfarin therapy also was discontinued for 3 to 4 days before blood examinations were conducted during the follow-up studies. Heparin, 5,000 U, was administered into the left atrium after transseptal puncture in each patient. Diuretics were discontinued on the day of PTMV. Digoxin, P-blockade, and Ca-blockade were discontinued for at least 5 half-lives before the study. No patient received aspirin or other antiplatelet regimens, and no patient received any nonsteroidal antiinflammatory drugs. xalatan generic

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty: Materials and Methods

Study Population
Nineteen patients who had symptomatic rheumatic MS (mean [± SD] mitral valve area, 1.05 ± 0.17 cm2; range, 0.6 to 1.29 cm2) without significant mitral, tricuspid, or aortic regurgitation, and left atrial thrombus, and had undergone PTMV were studied. There were 1 man and 18 women, ranging in age from 39 to 72 years (mean age, 57 ± 11 years). Fifteen patients were in permanent atrial fibrillation, and 4 patients were in sinus rhythm. Five patients had a history of cerebral thromboembolism. Ten patients were in New York Heart Association functional class III, and 9 patients were in New York Heart Association functional class II. No patient had a history of malignancy, inflammatory disease, collagen vascular disease, renal or liver disease, diabetes mellitus, hypertension, hyperlipidemia, infectious disease, deep venous thrombosis, pulmonary embolism, or recent surgery. canada health and care mall

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral Valvuloplasty

Mechanism of Reducing Platelet Activity by Percutaneous Transluminal Mitral ValvuloplastyPrevious studies have demonstrated that platelet activation occurs in peripheral blood of patients with rheumatic mitral stenosis (MS). Kataoka et al and Zaki et al have demonstrated that platelet activity significantly decreased after optimal percutaneous transluminal mitral valvuloplasty (PTMV), However, in these studies, platelet activation was evaluated by measuring the secretory substances of platelets (platelet factor 4 and (P-thromboglobulin), which are plasma markers used to evaluate platelet activation and cannot reflect changes in individual platelets. Therefore, no information regarding the correlation between the magnitude of increase in the mitral valve area after PTMV and the magnitude of decrease in the platelet activity after PTMV was provided in these studies.