Left atrial enlargement
Encyclopedia
Left atrial enlargement or left atrial dilation is a form of cardiomegaly
.
In the general population, obesity
appears to be the most important risk factor
for LAE. Also, a study found that LAE can occur as a consequence of atrial fibrillation (AF), although another study found that AF by itself does not cause LAE. The latter study also showed that the persistent type of AF was associated with LAE, but the number of years that a subject had AF was not.
LAE is suggested by an electrocardiogram
(ECG) that has a pronounced notch in the P wave
. However, if there is atrial fibrillation
, there wouldn't be a P wave present. In any case, LAE can be diagnosed and measured using an echocardiogram (ECHO). By approximating the shape of the left atrium as an ellipsoid, its volume can be calculated from measurements of its dimensions along three perpendicular directions.
Cardiomegaly
Cardiomegaly is a medical condition wherein the heart is enlarged. It is generally categorized in the following manner:* Cardiomegaly due to dilation* Cardiomegaly due to ventricular hypertrophy** Left ventricular hypertrophy...
.
In the general population, obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
appears to be the most important risk factor
Risk factor
In epidemiology, a risk factor is a variable associated with an increased risk of disease or infection. Sometimes, determinant is also used, being a variable associated with either increased or decreased risk.-Correlation vs causation:...
for LAE. Also, a study found that LAE can occur as a consequence of atrial fibrillation (AF), although another study found that AF by itself does not cause LAE. The latter study also showed that the persistent type of AF was associated with LAE, but the number of years that a subject had AF was not.
LAE is suggested by an electrocardiogram
Electrocardiogram
Electrocardiography is a transthoracic interpretation of the electrical activity of the heart over a period of time, as detected by electrodes attached to the outer surface of the skin and recorded by a device external to the body...
(ECG) that has a pronounced notch in the P wave
P wave (electrocardiography)
In electrocardiography, during normal atrial depolarization, the main electrical vector is directed from the SA node towards the AV node, and spreads from the right atrium to the left atrium...
. However, if there is atrial fibrillation
Atrial fibrillation
Atrial fibrillation is the most common cardiac arrhythmia . It is a common cause of irregular heart beat, identified clinically by taking a pulse. Chaotic electrical activity in the two upper chambers of the heart result in the muscle fibrillating , instead of achieving coordinated contraction...
, there wouldn't be a P wave present. In any case, LAE can be diagnosed and measured using an echocardiogram (ECHO). By approximating the shape of the left atrium as an ellipsoid, its volume can be calculated from measurements of its dimensions along three perpendicular directions.