Right Ventricular Dyssynchrony Before and After Pulmonary Thromboendarterectomy in Patients with Chronic Thromboembolic Pulmonary Hypertension
Background: Left ventricular dyssynchrony has been studied extensively, but this is not the case with right ventricular (RV) dyssynchrony. Our aim was to investigate RV dyssynchrony through 2D speckle strain imaging in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after pulmonary thromboendarterectomy (PTE). Methods: We measured 2D peak RV strain (%) of the RV free-wall and time to peak strain (ms) of its three freewall segments (base, mid, and apex) in 127 consecutive CTEPH patients (51 ± 14 years, 59% female) with adequate images pre- and post-PTE. RV strain was calculated using Epsilon Imaging EchoInsight® software. RV dyssynchrony was measured using two methods: the standard deviation of peak systolic strain and the standard deviation of time (ms) to peak strain (RVDT) between the three RV free-wall segments. Results: Mean RV free wall strain did not change significantly after PTE (−11.4 ± 5.7 to −11.2 ± 5.6%, p = 0.67). However, RV dyssynchrony improved dramatically after surgery in RVDP and RVDT (9.4 ± 6.2 to 5.4 ± 3.8%, p < 0.0001; 103 ± 65 to 56 ± 65 ms, p < 0.0001, respectively). Conclusions: There was a significant decrease in the standard deviation of the mean peak systolic strain and time to peak strain (dyssynchrony) of the three RV free-wall segments after PTE. The cause of this more uniform contraction of the right ventricle after PTE is unclear, but could stem from the marked change in pulmonary vascular resistance and mean pulmonary arterial pressure in this population.
