Low electrocardiographic voltage in pericardial effusion

Area of Science:

• Cardiology
• Medical Diagnostics

Background:

• Low electrocardiogram (ECG) voltage is often associated with pericardial effusion.
• The diagnostic utility of low ECG voltage in identifying pericardial effusion remains unclear.

Purpose of the Study:

• To investigate the relationship between pericardial effusion volume and low ECG voltage.
• To assess the diagnostic accuracy of low voltage criteria in pericardial effusion.

Main Methods:

• Studied 28 patients undergoing pericardial drainage.
• Measured QRS amplitude in limb leads and standard leads.
• Correlated effusion volume with QRS amplitude before and after drainage.
• Analyzed sensitivity and specificity of low voltage criteria.

Main Results:

• No significant correlation found between effusion volume and QRS amplitude (r = -0.30).
• Low voltage persisted in 9/14 patients post-drainage, often with thickened pericardium.
• Acceptable sensitivity for low voltage was observed only with large effusions and no left ventricular hypertrophy.
• Absolute low voltage showed specificity for moderate and large effusions in selected patients.

Conclusions:

• Low ECG voltage is not a reliable indicator of pericardial effusion volume.
• Absolute low voltage may be a specific, though not universally sensitive, marker for moderate to large pericardial effusions.
• Pericardial thickening can contribute to persistent low voltage after drainage.