1. Patients with early disease usually have grade I diastolic dysfunction that progresses to grade II as the severity of the disease advances.
2. In patients with advanced disease, grade III diastolic dysfunction is present and is characterized by mitral inflow E/A ratio > 2.5, DT of E velocity < 150 msec, IVRT <50 msec, and decreased septal and lateral e' velocities (3–4 cm/sec).
3. Patients with constrictive pericarditis usually have septal e' velocity higher than lateral e' velocity, or annulus reversus, and E/e' ratio should not be used to estimate LV filling pressures in patients with constrictive pericarditis.