User:Bob K31416/AF

http://www.hematology.org/Publications/50-Years-in-Hematology/4323.aspx

http://www.hematology.org/publications/50-years-in-hematology/4738.aspx

Fibrin is a protein that forms a mesh that traps red blood cells, while platelets, a type of blood cell, form clumps that add to the mass of the thrombus.

There are two classes of antithrombotic drugs: anticoagulants and antiplatelet drugs. Anticoagulants slow down clotting, thereby reducing fibrin formation and preventing clots from forming and growing. Antiplatelet agents prevent platelets from clumping and also prevent clots from forming and growing.

Anticoagulants Heparin and warfarin produce a highly variable anticoagulant effect in patients, requiring their effect to be measured by special blood tests and their dose adjusted according to the results.

Heparin acts immediately and is given intravenously (through the veins). Warfarin is swallowed in tablet form, but its anticoagulant effect is delayed for days. Therefore, until recently, patients requiring anticoagulants who were admitted to a hospital were started on a heparin infusion and were then discharged from the hospital after five to seven days on warfarin.

low-molecular-weight heparin LMWH is produced by chemically splitting heparin into one-third of its original size. It has fewer side effects than heparin and produces a more predictable anticoagulant response. replaced heparin for most indications. LMWH is injected subcutaneously (under the skin) in a fixed dose without the need for anticoagulant monitoring.

Antiplatelet Drugs Blood platelets are inactive until damage to blood vessels or blood coagulation causes them to explode into sticky irregular cells that clump together and form a thrombus.

aspirin in very low doses (much lower than that required to relieve a headache) blocked the production of a chemical in platelets that is required for platelet clumping.

clopidogrel. used with aspirin for stroke prevention

http://www.hematology.org/Publications/50-Years-in-Hematology/4736.aspx

To provide optimal protection from thrombosis with no risk of bleeding will be the next frontier of hematology research in antiplatelet therapy. It will require the identification of agents that can selectively block undesired, pathological thrombosis without interfering with physiologically protective hemostasis.

Antithrombotic therapy
Antithrombotic therapy  involves the use of anticoagulant, antiplatelet, or thrombolytic drugs to prevent or break up the formation of clots. Some examples are   aspirin, heparin, warfarin, and dabigatran. Which drug is used depends on a number issues including: cost, risk of stroke, risk of falls, compliance, and speed of desired onset of anticoagulation. Some other anticoagulants were discussed in a 2012 state-of-the-art paper but were not generally approved at that time for stroke prevention in AF: apixaban, rivaroxaban, and edoxaban.

Anticoagulation
Anticoagulation can be achieved through a number of means including the use of aspirin, heparin, warfarin, and dabigatran. Which method is used depends on a number issues including: cost, risk of stroke, risk of falls, compliance, and speed of desired onset of anticoagulation. Some other anticoagulants were discussed in a 2012 state-of-the-art paper but were not generally approved at that time for stroke prevention in AF: apixaban, rivaroxaban, and edoxaban.


 * Transesophageal Echocardiography Before Cardioversion of Recurrent Atrial Fibrillation: Does Absence of Previous Atrial Thrombi Preclude the Need of a Repeat Test? Shen2003


 * Consider TEE Before Cardioversion of AF Calkins2002, summary of the following article


 * Use of Transesophageal Echocardiography to Guide Cardioversion in Patients with Atrial Fibrillation Klein2001


 * Mitral regurgitation reduces the risk of stroke in patients with nonrheumatic atrial fibrillation (Nakagami1998)


 * Prevention of Recurrent Lone Atrial Fibrillation by the Angiotensin-II Converting Enzyme Inhibitor Ramipril in Normotensive Patients (Belluzzi2009)

Misc webpages
 * Epocrates Online
 * HeartPatients Foundation
 * MayoClinic
 * eMedicine Health
 * Heart Rhythm Society