Possible pitfalls in pulse wave Doppler recordings of atrial and ventricular filling:
Similar respiratory variation in mitral inflow velocity may occur in several clinical settings such as acute dilatation of the heart, pulmonary embolism, right ventricular infarct, conditions in which a dilated right ventricle helps in the differential diagnosis
Increased respiratory variation in mitral and tricuspid inflow velocities are seen in chronic obstructive lung disease without pericardial constriction due to respiratory changes in intrathoracic pressure. In this setting, E/A ratio is lower, EDT is more prolonged and there is a more pronounced respiratory variation in superior vena cava flow with increase in forward flow and systolic dominant flow with inspiration
Persistence of respiratory variation in mitral and tricuspid inflow velocities after pericardiectomy
Absence of respiratory variation in mitral inflow velocity in cases of markedly elevated left atrial pressure
Reduced respiratory variation in mitral inflow velocity in atrial fibrillation, with more pronounced respiratory change in D-wave velocity in this setting.