Lone atrial fibrillation is defined as:
(1) absence of structural heart disease
(2) absence of any other causal factor to explain the AF
Parameters used to predict the risk of AF recurrence:
(1) history of previous episodes of AF
(2) anteroposterior left atrial diameter in mm corrected for body surface area in square meters
anteroposterior left atrial diameter corrected for BSA =
= (diameter in mm by echocardiography) / (BSA in square meters)
The risk of AF recurrence increases with the increase in left atrial diameter.
Past History of AF
|
LA Diameter (corrected for BSA)
|
Mean Risk of AF Recurrence at 6 months
|
no (new onset)
|
<= 23 mm per square m
|
35%
|
no (new onset)
|
> 23 mm per square m
|
71%
|
yes (recurrent)
|
<= 23 mm per square m
|
57%
|
yes (recurrent)
|
> 23 mm per square m
|
90%
|
where:
• The risks listed in the tables are mean values that may underestimate or overestimate the risk at the extremes. For example, a patient with new onset and an LA diameter corrected for BSA < 18.1 mm per square meter had a risk of < 20%.