Yes, HFpEF Characteristically Causes Left Atrial Dilation on Echocardiography
Left atrial enlargement is a hallmark structural finding in HFpEF and serves as a key diagnostic criterion, reflecting chronic elevation of left ventricular filling pressures. 1
Why the Left Atrium Dilates in HFpEF
The pathophysiology is straightforward: HFpEF causes impaired left ventricular relaxation and increased chamber stiffness, which elevates left ventricular end-diastolic pressure. 1 This pressure is transmitted backward to the left atrium chronically, causing progressive atrial remodeling and dilation. 2 The left atrium essentially serves as a "pressure gauge" for chronic diastolic dysfunction. 3
Diagnostic Significance
Left atrial volume index (LAVI) >34 mL/m² is one of the five core structural parameters mandated by the European Society of Cardiology guidelines for diagnosing HFpEF. 4 This threshold applies regardless of whether the patient is in sinus rhythm or atrial fibrillation. 1, 4
The diagnostic utility is substantial:
A simplified first-step diagnostic approach using LA volume indexed for height² (LAViH2 >35.5 ml/m² in sinus rhythm, or >38.6 ml/m² in atrial fibrillation) combined with elevated natriuretic peptides identifies 60% of HFpEF patients with 88% specificity and 97% positive predictive value. 5
This LA/NP approach reduces the need for additional complex diagnostics by 27-57% when used before applying full diagnostic algorithms. 5
Integrated Assessment Context
While left atrial dilation is characteristic, no single echocardiographic parameter can reliably diagnose HFpEF; an integrated assessment of multiple markers is mandatory. 4 The ESC guidelines require combining:
Structural parameters: LAVI >34 mL/m², left ventricular mass index (LVMI >115 g/m² in men, >95 g/m² in women), and LV hypertrophy 1, 4
Diastolic function indices: E/e' ratio (>15 indicates high filling pressures), septal e' <7 cm/s or lateral e' <10 cm/s 4
Hemodynamic markers: Tricuspid regurgitation velocity and estimated pulmonary artery pressures 1, 4
Clinical Pitfall to Avoid
Do not assume that a normal-sized left atrium excludes HFpEF, particularly in early disease or acute presentations. 1 However, the presence of left atrial enlargement in a patient with preserved ejection fraction and heart failure symptoms strongly supports the diagnosis and reflects the chronicity of elevated filling pressures. 1, 2
Left atrial reservoir strain may be used as an alternative to LA volume, showing comparable diagnostic performance. 5