Fecting several steps in the anticoagulation pathway to prevent clotting. Vka : see vitamin k antagonist v-tach (vt): short for ventricular tachycardia.   a fast heart rhythm that originates in one of the ventricles. buy generic viagra online It is a potentially life-threatening arrhythmia, because it may lead to ventricular fibrillation---very rapid uncoordinated fluttering contractions of the ventricles resulting in loss of synchronization between heartbeat and pulse beat. Unlike a-fib, it can be very dangerous and result in sudden death. Warfarin: the generic name of an anticoagulant whose product name is "coumadin. " see medications. Watchman device: the theory behind the watchman device is most a-fib clots originate in the left atrial appendage (laa). The watchman device closes off the laa where 90-95% of a-fib strokes come from. It's a very low risk procedure that takes only a short time to install. viagra for sale Then you would usually not need to be on blood thinners. cheap viagra online     here's how it works:once a patient's left atrial appendage is measured, a wide-sheathed catheter with a spline is used to insert the watchman device which has a self-expanding nitinol (a special metal) open-ended circular frame. generic viagra canada The atrial surface of this frame is covered with a thin, permeable clx μm (micron) pore filter made of polyester material (polyethylene terephthalate known as dacron or pet). This filter allows blood to pass through while stopping clots. cheap generic viagra Little hooks or anchors called fixation barbs at the middle of the device make sure it is attached firmly to the laa wall. viagra online The watchman device comes in multiple sizes from 21mm to 33mm to accommodate the different sizes of laas.      before the catheter is removed (which fixes the watchman device in place), contrast agents are used to make sure the watchman device is stable and entirely closes off the laa opening. Over time heart tissue grows over the polyester (pet) material so that it completely closes off the laa with smooth heart tissue similar to other heart surfaces. In this occlusion slide, heart tissue has completely covered the watchman device after only nine months. viagra safe alternative     some doctors are inserting the watchman device in as little as 20 minutes. does viagra 100 look like It is a low risk procedure with no surgery or ablation involved. can get viagra prescription uk     patients on coumadin continue to take it for six weeks after the watchman device is ins.