Patient selection: atrial fibrillation
Parameters:
(1) left ventricular ejection fraction (LVEF) in percent
(2) left atrial volume index (left atrial volume in mL divided by body surface area in square meter)
(3) CHADS2 score
ratio of LVEF to left atrial volume index =
= (LVEF in percent) / (left atrial volume index)
A patient is at low risk for thrombus formation in the left atrial appendage if all of the following are present:
(1) CHADS2 0 or 1 (<= 1)
(2) LVEF > 55%
(3) left atrial volume index < 28 mL per square meter
A ratio of LVEF to left atrial volume index <= 1.5 was 100% sensitive but 56% specific for thrombus formation in the left atrial appendage.
Additional risk factors for thrombus formation:
(1) congestive heart failure
(2) reduced left atrial flow velocity
(3) elevated CHADS2 score
|
CHADS2
|
Percent with Thrombus
|
|
0
|
1.6%
|
|
1
|
10.7%
|
|
2 or 3
|
19.5%
|
|
>= 4
|
32%
|
