Left Atrium Size

MITRAL STENOSIS WITH ENLARGED LEFT ATRIUM – WIDENED CARINAL ANGLE DOUBLE DENSITY ENLARGED LEFT ATRIAL APPENDAGE
The frontal CXR demonstrates findings consistent with mitral stenosis including a widened carinal angle (teal blue and black arc), a double density (red arc) and an enlarged left atrial appendage (maroon arc).
The overall shape of the heart is triangular suggesting right ventricular enlargement. A mitral valve prosthesis is in position
Courtesy of Radiopaedia

 

A normal lateral examination of the chest X-ray is shown to exemplify the positioning of the cardiac chambers showing the right ventricular outflow tract (RVOT) anteriorly, the left atrium (LA) posteriorly and superiorly, the left ventricle (LV) posteriorly and inferiorly and the inferior vena cava (IVC) as a separate shadow posterior to the LV.
Ashley Davidoff MD
Stolzmann, P
Reference values for quantitative left
ventricular and left atrial measurements
in cardiac computed tomography
Eur Radiol (2008) 18: 1625–1634

 

Left Atrial Diameter

 

  • normal left atrial AP diameter
    • women: <4.0 cm
    • men: <4.1 cm

An accurate AP measurement is made on the three-chamber view on a gated cardiac CT. The AP left atrial diameter on a non-gated contrast-enhanced CT can only be an estimate since foreshortening of the chamber and the cardiac cycle cannot be accounted for.

Atrial volume measurements are considered more accurate than either AP or area measurements.

 

4 chamber view of the normal heart in atrial diastole and ventricular systole using MRI shows normal measurements of the left atrium (LA)
Ashley Davidoff MD
Axial view of the normal heart in atrial diastole and ventricular systole using MRI shows normal measurements of the left atrium (LA)
Ashley Davidoff MD

Left Atrial Volume

The atrial volume can be calculated with: 8/3π[(area of the four chamber view)*(area of the two chamber view)/(shortest inferior-superior length from the annular plane to the back wall of the atrium)]

  • normal atrial volume
    • women: <53 mL
    • men: <59 mL
Enlarged Left Atrium
MITRAL STENOSIS WITH ENLARGEMENT OF THE LEFT ATRIUM, RIGHT ATRIUM, AND RIGHT VENTRICLE
35 year old patient with severe mitral stenosis . with left atrial enlargement (LAE) characterized by elevation of the left mainstem bronchus, straightening of the left heart border, and prominence of the upper 1/3 of the posterior border of the heart. The right atrium is also enlarged characterized by a rotund right heart border. There is right ventricular enlargement characterized by filling in of the retrosternal airspace.
Ashley Davidoff MD

 

 

RHEUMATIC  MITRAL STENOSIS (MS) AND PULMONARY HYPERTENSION MITRAL STENOSIS (MS) AND PULMONARY HYPERTENSION- TRIANGULAR HEART, LAE STRAIGHT HEART BORDER, CEPHALISATION
87 year old male with findings consistent with mitral stenosis , characterised by calcified mitral valve, enlarged left atrium, normal sized left ventricle,with enlarged right atrium, right ventricle and main pulmonary artery.
Pure mitral stenosis is most commonly caused by rheumatic heart disease
Ashley Davidoff MD
MITRAL STENOSIS (MS) AND PULMONARY HYPERTENSION – STRAIGHT HEART BORDER, ENLARGED MPA, LAA, RV AND TRICUSPID REGURGITATION
87 year old male with findings consistent with mitral stenosis , characterised by calcified mitral valve, enlarged left atrium, normal sized left ventricle,with enlarged right atrium, right ventricle and main pulmonary artery.
Pure mitral stenosis is most commonly caused by rheumatic heart disease
Ashley Davidoff MD
MITRAL STENOSIS (MS) AND PULMONARY HYPERTENSION – STRAIGHT HEART BORDER, ENLARGED MPA, LAA, RV AND TRICUSPID REGURGITATION
87 year old male with findings consistent with mitral stenosis , characterised by calcified mitral valve, enlarged left atrium, normal sized left ventricle,with enlarged right atrium, right ventricle and main pulmonary artery.
Pure mitral stenosis is most commonly caused by rheumatic heart disease
Ashley Davidoff MD

 

LAA pushing on Left MAin Bronchus
References and Links