Disparate Patterns of Left Ventricular Mechanics Differentiate Constrictive Pericarditis From Restrictive Cardiomyopathy

ObjectivesThe purpose of this study was to compare the longitudinal, circumferential, and radial mechanics of the left ventricle (LV) in patients with constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM).BackgroundDiastolic dysfunction in CP is related to epicardial tethering and pericardial constraint, whereas in RCM it is predominantly characterized by subendocardial dysfunction. Assessment of variations in longitudinal and circumferential deformation of LV might be useful to distinguish these 2 conditions.MethodsLongitudinal, radial, and circumferential mechanics of the LV were quantified by 2-dimensional speckle tracking of B-mode cardiac ultrasound images in 26 patients with CP, 19 patients with RCM, and 21 control subjects.ResultsIn comparison with control subjects, patients with CP had significantly reduced circumferential strain (base; −16 ± 6% vs. −9 ± 6%; p < 0.016), torsion (3 ± 1°/cm vs. 1 ± 1°/cm; p < 0.016), and early diastolic apical untwisting velocities (Er; 116 ± 62°/s vs. −36 ± 50°/s; p < 0.016), whereas longitudinal strains, displacement, and early diastolic velocities at the LV base (Em) were similar to control subjects. In contrast, patients with RCM showed significantly reduced longitudinal displacement (base; 14.7 ± 2.5 cm vs. 9.8 ± 2.8 cm; p < 0.016) and Em (−8.7 ± 1.3 cm/s vs. −4.4 ± 1.1 cm/s; p < 0.016), whereas circumferential strain and Er were similar to those of control subjects. For differentiation of CP from RCM, the area under the curve was significantly higher for Em in comparison with Er (0.97 vs. 0.76, respectively; p = 0.01). After pericardiectomy, there was a significant decrease in longitudinal early diastolic LV basal myocardial velocities (7.4 cm/s vs. 6.8 cm/s; p = 0.023). Circumferential strain, torsion, and Er, however, remained unchanged.ConclusionsDeformation of the LV is constrained in the circumferential direction in CP and in the longitudinal direction in RCM. Subsequent early diastolic recoil of LV is also attenuated in each of the 2 directions, respectively, uniquely differentiating the abnormal diastolic restoration mechanics of the LV seen in CP and RCM.