Differential Diagnosis for Biatrial Enlargement and Diastolic Dysfunction

Given the presentation of a 70-year-old man with shortness of breath, a transthoracic echocardiogram (TTE) showing biatrial enlargement, grade 3 diastolic dysfunction, and normal left ventricular (LV) function, the following differential diagnoses are considered:

• Single Most Likely Diagnosis
  • Hypertension: Chronic hypertension is a common cause of biatrial enlargement and diastolic dysfunction due to increased afterload leading to LV hypertrophy and subsequent diastolic impairment. The normal LV function (ejection fraction) in the context of diastolic dysfunction supports this diagnosis, as systolic function can remain preserved until late in the disease process.
• Other Likely Diagnoses
  • Heart Failure with Preserved Ejection Fraction (HFpEF): This condition is characterized by symptoms of heart failure in the presence of a normal ejection fraction, often with evidence of diastolic dysfunction. Biatrial enlargement can be seen due to increased filling pressures.
  • Atrial Fibrillation: Although not directly mentioned, the presence of biatrial enlargement could suggest a history of or predisposition to atrial fibrillation, which can lead to heart failure symptoms due to rapid ventricular rates and loss of atrial contraction.
  • Coronary Artery Disease: While the LV function is normal, coronary artery disease could lead to diastolic dysfunction through ischemia or previous myocardial infarction causing scar tissue, which might not significantly impair systolic function but affects diastolic relaxation.
• Do Not Miss Diagnoses
  • Cardiac Amyloidosis: Although less common, cardiac amyloidosis can present with diastolic dysfunction, biatrial enlargement, and preserved systolic function. It's crucial to consider this diagnosis due to its poor prognosis and the availability of specific treatments. Amyloidosis can be suggested by echocardiographic features such as a thickened left ventricular wall in the absence of hypertension or other explanations.
  • Constrictive Pericarditis: This condition can mimic the symptoms and echocardiographic findings of restrictive cardiomyopathy (such as cardiac amyloidosis) and must be considered, especially if there's a history suggestive of pericardial disease.
• Rare Diagnoses
  • Fabry Disease: A genetic disorder leading to the accumulation of globotriaosylceramide in various cells, including cardiomyocytes, resulting in hypertrophic cardiomyopathy and potential diastolic dysfunction.
  • Sarcoidosis: Can involve the heart, leading to various manifestations, including restrictive cardiomyopathy, which might present with diastolic dysfunction and biatrial enlargement.
  • Hemochromatosis: Iron overload can lead to a restrictive cardiomyopathy picture, with diastolic dysfunction being an early finding.

Each of these diagnoses has different implications for management and prognosis, highlighting the importance of a thorough diagnostic evaluation.