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

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

Partho P. Sengupta, Vijay K. Krishnamoorthy, Walter P. Abhayaratna, Josef Korinek, Marek Belohlavek, Thoralf M. Sundt, III, Krishnaswamy Chandrasekaran, Farouk Mookadam, James B. Seward, A. Jamil Tajik, Bijoy K. Khandheria

The study investigated the longitudinal, circumferential, and torsional mechanics of the left ventricle (LV) in 26 patients with constrictive pericarditis (CP), 19 patients with restrictive cardiomyopathy (RCM), and 21 age- and gender-matched control subjects. Patients with constriction showed relatively normal longitudinal LV mechanics, although circumferential strain, torsion, and early diastolic untwisting velocities were reduced. In contrast, patients with restriction showed reduced longitudinal strain, displacement, and early diastolic velocities, whereas circumferential and torsional mechanics were preserved. Assessment of axial and torsional deformation of the LV provides unique insight into 2 distinct patterns of early diastolic restoration mechanics seen in CP and RCM. These observations add significantly to the hemodynamic data at rest and during various phases of respiration as well as the muscle mechanics known to differentiate the 2 clinical entities.

Objectives

The 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).

Background

Diastolic 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.

Methods

Longitudinal, 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.

Results

In 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.

Conclusions

Deformation 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.