Left atrial dilation

Pathological enlargement of the left atrial chamber (Left Atrial Volume Index >38 mL/m² or linear left atrial diameter >4.1 cm), typically reflecting chronic pressure and/or volume overload and associated with an increased risk of atrial fibrillation and thromboembolic events.

Causes

• Pressure overload causes

  • Chronic hypertension

  • Left ventricular diastolic dysfunction

  • Heart failure with preserved ejection fraction (HFpEF)

  • Aortic stenosis

• Volume overload causes

  • Mitral regurgitation

  • High-output cardiac states

  • Left-to-right intracardiac shunts

• Valvular heart disease

  • Mitral stenosis

  • Mitral regurgitation

  • Mixed mitral valve disease

• Myocardial causes

  • Heart failure

  • Dilated cardiomyopathy

  • Hypertrophic cardiomyopathy

  • Restrictive cardiomyopathy

  • Chronic left ventricular systolic dysfunction

• Rhythm-related causes

  • Chronic atrial fibrillation

  • Recurrent atrial tachyarrhythmias

• Other causes

  • Obesity

  • Obstructive sleep apnea

  • Chronic kidney disease with volume overload

  • Congenital heart disease causing left atrial volume overload