Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although successful electrical cardioversion is accomplished in most cases without any evidence of embolic stroke, a few patients have experienced this catastrophe. The current thinking is that when electrical energy is applied to the chest wall, the atrium, although it returns to sinus rhythm, is stunned. It is not known how long this stunning lasts in the individual patient nor whether high energy produces stunning and low energy does not. Nor is it known whether chemical conversion of atrial fibrillation to sinus rhythm affects the atrium in the same way. However, the atrium seems to recover more quickly in patients with a short duration of atrial fibrillation and these patients may not require the usual four weeks of postcardioversion anticoagulation. Based on what we know, or more precisely what we don't know, it seems reasonable to ensure that every patient with atrial fibrillation is anticoagulated during and after DC cardioversion to sinus rhythm. Of course, this is easy to do with intravenous heparin, but that requires hospitalization. Perhaps subcutaneous heparin in high doses would suffice until the patient can be anticoagulated with coumadin. From the research perspective it might be interesting to perform serial echo/Doppler studies on these patients to identify when the individual patient's atrial function returns to normal. This might provide a clinical rationale for discontinuing anticoagulation. Comparing the time to return of normal atrial function (as measured by Doppler echo) between patients undergoing pharmacologic cardioversion versus electrical cardioversion and studying the relationship of the amount of electrical energy required for cardioversion versus the duration of stunning would be clinical research projects of interest to clinicians.
 ...
PMID:Atrial fibrillation, transesophageal echo, electrical cardioversion, and anticoagulation. 772 Feb 89

Warfarin is an established treatment for prevention of ischaemic stroke in patients with atrial fibrillation, but the value of this agent relative to aspirin in unclear. In the first Stroke Prevention in Atrial Fibrillation (SPAF-I) study, direct comparison of warfarin with aspirin was limited by the small number of thromboembolic events. SPAF-II aims to address this issue and also to assess the differential effects of the two treatments according to age. We compared warfarin (prothrombin time ratio 1.3-1.8, international normalised ratio 2.0-4.5) with aspirin 325 mg daily for prevention of ischaemic stroke and systemic embolism (primary events) in two parallel randomised trials involving 715 patients aged 75 years or less and 385 patients older than 75; we sought reductions in the absolute rate of primary events by warfarin compared with aspirin of 2% per year and 4% per year, respectively. In the younger patients, warfarin decreased the absolute rate of primary events by 0.7% per year (95% CI-0.4 to 1.7). The primary event rate per year was 1.3% with warfarin and 1.9% with aspirin (relative risk [RR] 0.67, p = 0.24). The absolute rate of primary events in low-risk younger patients (without hypertension, recent heart failure, or previous thromboembolism) on aspirin was 0.5% per year (95% CI 0.1 to 1.9). Among older patients, warfarin decreased the absolute rate of primary events by 1.2% per year (95% CI-1.7 to 4.1). The primary event rate per year was 3.6% with warfarin and 4.8% with aspirin (RR 0.73, p = 0.39). In this older group, the rate of all stroke with residual deficit (ischaemic or haemorrhagic) was 4.3% per year with aspirin and 4.6% per year with warfarin (RR 1.1). Warfarin may be more effective than aspirin for prevention of ischaemic stroke in patients with atrial fibrillation, but the absolute reduction in stroke rate by warfarin is small. Younger patients without risk factors had a low rate of stroke when treated with aspirin. In older patients the rate of stroke (ischaemic and haemorrhagic) was substantial, irrespective of which agent was given. Patient age and the inherent risk of thromboembolism should be considered in the choice of antithrombotic prophylaxis for patients with atrial fibrillation.
 ...
PMID:Warfarin versus aspirin for prevention of thromboembolism in atrial fibrillation: Stroke Prevention in Atrial Fibrillation II Study. 791 Dec 13

Published and ongoing studies of drug therapy for preventing stroke in patients with nonrheumatic atrial fibrillation (AF) are discussed, and updated recommendations are provided. Stroke is the most common complication of nonrheumatic AF; there are more than 75,000 such strokes each year in North America. Nonrheumatic AF increases the risk of stroke almost sixfold. Emboli from clots that form in the left atrium because of ineffective atrial contraction and turbulent blood flow may cause most of these strokes. The results of six randomized trials of antithrombotic therapy in patients with nonrheumatic AF are now available. In almost all of these trials, warfarin therapy significantly reduced the risk of stroke. One trial showed that aspirin significantly reduced the risk of stroke, but another trial did not support that finding. Ongoing trials are addressing the efficacy and risks of aspirin plus low-dose warfarin and very low intensity anticoagulation. Overall, the data suggest that patients who are younger than 75 years of age and who lack risk factors can be adequately protected against stroke with aspirin. Patients younger than 75 years who have risk factors but no contraindications to warfarin should receive warfarin. Patients older than 75 years appear to benefit from anticoagulation therapy, but this benefit is offset by the higher risk of bleeding complications. Lone AF is best managed with aspirin. Warfarin is superior to aspirin as a secondary intervention in patients with a recent thromboembolic event. Strategies for preventing stroke in patients with nonrheumatic atrial fibrillation continue to be refined.
 ...
PMID:Preventing stroke in patients with nonrheumatic atrial fibrillation. 804 36

Heart disease is the probable source of emboli in 20% to 25% of cases of cerebral infarction. The risk of early death is 14 times greater than the risk of recurrent stroke in patients with cardioembolism: Selection of diagnostic tests should be based on the clinical evidence for cardiac disease, the patient's age, and the identification of other likely causes of stroke. Treatment should focus on decreasing mortality due to cardiac disease as well as preventing recurrent stroke. Warfarin is currently the first treatment of choice for most patients with presumed cardioembolism. Aspirin is an appropriate alternative if warfarin cannot be used.
Heart Dis Stroke
PMID:Heart disease and stroke. 815 89

1. Atrial fibrillation is a common disorder in the elderly. 2. Atrial fibrillation increases the risk of stroke five times that of patients in sinus rhythm. 3. Warfarin reduces the risk of stroke by two-thirds in this population. Aspirin might reduce the risk of stroke but by a lesser amount. 4. In this sample, statewide use of Warfarin for primary prophylaxis in patients under 80 was 21% (95% C.I. 14-28%) and use of either Warfarin or aspirin was 42% (95% C.I. 34-50%). 5. Smaller hospitals and hospitals not in Central Arkansas use Warfarin less frequently than larger institutions for prophylaxis of stroke. Likewise, these hospitals are less likely to give any stroke prophylaxis to patients with this condition.
 ...
PMID:Arkansas Foundation for Medical Care report: preventing stroke in atrial fibrillation. 816 27

Epidemiologic studies have shown that atrial fibrillation (AF) raises the risk of stroke approximately fivefold, and that because AF is so common among the stroke-prone elderly, it accounts for about 15% of all strokes. Five recently completed, randomized trials consistently found that the anticoagulant warfarin can prevent most of the additional stroke risk due to AF. This effect was seen at low doses. The trials have also demonstrated that warfarin therapy can be safe if careful patient selection and monitoring are implemented. Three of the trials provided inconsistent, and currently inconclusive evidence about the efficacy of aspirin. The trials have not settled the anticoagulation decision for all patients. Warfarin remains a demanding and risky therapy, which many patients and physicians do not find attractive. Future research should attempt to refine the risk of stroke, and of major hemorrhage during warfarin therapy among patients with AF, and should seek safer, less demanding, yet effective antithrombotic regimens.
 ...
PMID:Overview of the randomized trials to prevent stroke in atrial fibrillation. 816 38

Because of its prevalence in the population and its associated underlying diseases and morbidity, atrial fibrillation (AF) is an important and costly health problem. Advancing age, diabetes, heart failure, valvular disease, hypertension, and myocardial infarction predict the occurrence of AF within a population. The management of AF is complex and involves prevention of thromboembolic complications and treatment of arrhythmia-related symptoms. Stroke occurs in 4.5% of untreated patients with AF per year. Independent risk factors for stroke in nonrheumatic patients with AF are advanced age; a history of prior embolism, hypertension, or diabetes; and echocardiographic findings of left atrial enlargement and left ventricular dysfunction. Warfarin decreases stroke by two-thirds and death by one-third; aspirin is only about half as effective overall and is insufficient therapy for those with risk factors for stroke. Options for thromboembolic prophylaxis are use of warfarin for all in whom it is safe or, alternatively, warfarin for those with risk factors and aspirin for those without risk factors. One-half of the patients with AF are 75 years of age or older. The uniform applicability and relative safety of warfarin therapy in this age-group are controversial. Specific therapy for the arrhythmia should be dictated by the need to control symptoms. Symptomatic treatments include rate-control medications and strategies designed to terminate and prevent arrhythmia recurrence. Digoxin, beta-adrenergic blockers, verapamil, and diltiazem slow excessive ventricular rates in patients with AF and may favorably manage comorbid conditions. The efficacy of anti-arrhythmic medications is only 40 to 70% per year in preventing recurrences of AF, and these agents, except amiodarone, may increase the risk of sudden death in patients with certain types of organic heart disease and AF. The use of nonpharmacologic symptomatic therapies such as atrioventricular node modification or ablation with a rate-response pacemaker or surgical intervention is increasing.
 ...
PMID:Management of atrial fibrillation in adults: prevention of thromboembolism and symptomatic treatment. 857 89

All patients (285) undergoing mitral valve replacement (MVR) with a Carpentier-Edwards (C-E) bioprosthesis +/- coronary bypass grafts (CABG) were reviewed (109 men and 176 women with a median age of 70 years). Overall, the 5-year survival rate was 58.9%, 62.7% for MVR (199 patients) and 50.1% for MVR+CABG (86 patients). Late survival was adversely affected by the operative time variables of NYHA class IV, older (> or = 70 years) age, low (> or = 56%) ejection fraction (EF), and the additional performance of associated procedures+CABG with MVR (P < or = 0.001). The 5-year freedom from stroke rate was 89.2%, 89.1% for MVR and 90.2% for MVR +/- CABG. Advanced heart class was the only significant variable associated with a greater risk of late stroke (P < or = 0.01). Neither chronic preoperative atrial fibrillation nor operative obliteration of the left atrial appendage increased or decreased the late risk of stroke in patients following MVR. Hazard function for stroke occurring in the first postoperative year (first 48 h excluded to discount intraoperative events) demonstrated the highest rate within the first month (40%), rapidly diminishing thereafter. This pattern was reproduced in the 12-year hazard function in that the rate of stroke occurrence was greatest in the first year (6.7%) following implantation. The mean stroke rate over 12 years was 2.5%. Strokes following MVR +/- CABG are more likely to occur in older and more compromised patients, and the higher early rate is not reflected in the mean rate. A more aggressive approach to early anticoagulation with IV heparin, Coumadin, and possibly antiplatelet therapy is advocated to reduce this complication rate.
 ...
PMID:The risk of stroke in the early postoperative period following mitral valve replacement. 875 Dec 49

Warfarin potassium (warfarin) is one of anticoagulants. Its anticoagulant effect is induced by inhibiting vitamin K in a complex manner. It is used effectively and safely in preventing cerebral embolism of cardiac origin, provided that thrombotest (TT) values is maintained from 10 to 20%. A 75-year-old man with atrial fibrillation and cardiomyopathy had cerebral embolism in the territory of the right middle cerebral artery. Warfarin therapy was started to prevent the recurrence of embolic stroke. TT values had been well controlled until intake of chlorella, but they rose above the therapeutic limit after its intake. There was no evidence of discontinuing warfarin, or taking drugs containing vitamin K or Natto. Chlorella is one of vitamin K-rich foods. Thus, it may inhibit the anticoagulant effect of warfarin.
 ...
PMID:[Warfarin therapy and chlorella]. 877 8

Patients with non-rheumatic atrial fibrillation have a fivefold increased risk of stroke. Warfarin reduces this risk by approximately two thirds, but evidence for benefit from aspirin is less compelling. We assessed whether our current practice reflects the message of the trials. In a retrospective case record study we reviewed notes of 131 patients with atrial fibrillation (AF), mean age 79 (range 53-95) years, admitted to a medical unit (72) or geriatric assessment unit (59). Thirty-two patients had paroxysmal AF. Of 115 patients with nonrheumatic AF, 36 (31%) had one or more recorded contraindication to anti-coagulation. Although 79 patients (69%) had no recorded contraindication to warfarin, only 2 took warfarin and 15 aspirin prior to admission. Ten patients commenced warfarin and 8 aspirin before discharge. Thirty-nine patients (53%) without contraindication, were discharged without antithrombotic therapy. Despite evidence to support anticoagulating patients with non-rheumatic AF, this rarely occurs.
 ...
PMID:Antithrombotic therapy prescribed for patients with non-rheumatic atrial fibrillation. 877 57


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>