Version July 2025
| Parameter | Favors constrictive pericarditis | Favors restrictive cardiomyopathy |
| Echocardiography | ||
| Interventricular septal shift (bounce) | Present | Absent |
| Inspiratory fall in mitral E velocity* | ≥14.6% | <14.6% (usually <10%) |
| Hepatic venous flow | Ratio of expiratory diastolic reversal velocity to systolic forward velocity ≥0.79 | Inspiratory diastolic flow reversal |
| Medial e' | ≥8 cm/s¶ | <8 cm/s |
| Medial e'/lateral e'Δ | ≥0.88 | <0.88 |
| Absolute global longitudinal strain | >16% | ≤10% |
| Cardiac magnetic resonance imaging | ||
| Relative atrial volume ratio (LA/RA volume) | ≥1.32 | ≤1.32 |
| Pericardial thickness◊ | >4 mm | Normal |
| Pericardial motion | Tethered pericardium on tagged CMR | Normal pericardial motion |
| Late gadolinium enhancement | Enhancement of the pericardium | Characteristic enhancement pattern for some causes of RCM (eg, amyloidosis, sarcoidosis) |
| Ventricular interdependence (cine CMR maximal septal respiratory excursion) | >11% | <8% |
| Cardiac computed tomography | ||
| Pericardial thickness and appearance | >4 mm Pericardium may be calcified | ≤4 mm (generally <3 mm) |
| Contrast enhancement | Pericardial enhancement may be identified | No pericardial enhancement |
| LV and RV walls | LV and RV wall thicknesses may be normal or increased | |
| Nuclear imaging | ||
| FDG-PET | Uptake may be present, particularly with TB pericarditis | Uptake with sarcoidosis |
| Technetium-99m-pyrophosphate scintigraphy | Uptake with transthyretin amyloidosis | |
| Cardiac catheterization parameters | ||
| Respiratory change in LV and RV pressures§ | Discordant | Concordant |
| RAP/PCWP ratio | >0.77 | ≤0.77 |
BNP: B-type natriuretic peptide; CMR: cardiovascular magnetic resonance; CP: constrictive pericarditis; CT: computed tomography; E: early diastolic filling; e': early mitral annular velocity; FDG-PET: 18F-fluorodeoxyglucose positron emission tomography; IVRT: isovolumic relaxation time; LA: left atrial; LV: left ventricular; PCWP: pulmonary capillary wedge pressure; RA: right atrial; RAP: right atrial pressure; RCM: restrictive cardiomyopathy; RV: right ventricular; TB: tuberculous.
* LV filling velocity is driven by the gradient between LA and LV diastolic pressure. When LA pressure is greatly elevated in a patient with CP, respiratory variation in ventricular filling may not be observed, whereas patients with lower LA pressure (ie, due to volume depletion or earlier stage of disease) may have more noticeable changes in ventricular filling velocities with respiration. The ability to assess respirophasic changes in filling velocities is challenging in patients with atrial fibrillation due to the presence of variable cardiac cycle length from beat to beat.
¶ In patients with atrial fibrillation or atrial flutter, the cutoff for medial e' velocity is ≥11 cm/s rather than ≥8 cm/s.
Δ Mitral lateral (and tricuspid lateral) annular e' velocities are commonly reduced in patients with CP while e' velocities of the medial annulus are preserved (termed "annulus reversus"). This discrepancy between lateral and medial e' velocities is not generally observed in RCM.
◊ The pericardium is thickened in most patients with CP. However, a minority of patients with CP do not have thickened pericardium, so the presence of normal pericardial thickness does not exclude CP.
§ In patients with CP, there is an increase in aortic ejection time and a decrease in pulmonic ejection time with expiration, so the difference between aortic ejection time and pulmonic ejection time increases. In patients without CP, with expiration, aortic ejection time is generally unchanged, while the pulmonic ejection fraction is unchanged or may increase slightly, so the difference between aortic ejection time and pulmonic ejection time is unchanged or decreases slightly.