Impact of Right Ventricular Function on Left Ventricular Torsion and Ventricular Deformations in Pulmonary Artery Hypertension Patients

Introduction: Ventricular interdependence in pulmonary arterial hypertension (PAH) by the use of most recent echocardiographic techniques is still rare. The current case-controlled study aims to assess left ventricular (LV) torsion in patients with PAH.

Methods: The study included 42 cases of moderate to severe PAH and 42 age and gender-matched healthy controls between March 2016 and January 2018. All the patients and controls undergo routine practice echocardiography using the Vivid 7-echocardiography (2.5MHz transducer) system.

Results: The LV twisting parameters, peak basal rotation, peak apical rotation, and twist were similar among both cases and controls, however, LV torsion was significantly (p=0.04) impacted. Right ventricular (RV) longitudinal deformation was clinically significant in the cases compared to controls: RV systolic strain imaging (p=0.001, 95% CI-9.75 to -2.65), RV systolic strain rate (p=0.01, 95% CI-0.99 to -0.09), and RV late diastolic strain rate (p=0.01, 95% CI-0.64 to -0.85). Although PAH did not impact longitudinal LV deformations significantly. At basal level circumferential strain and strain rate were significantly impacted (p=0.005, 95% CI-4.38 to -0.70; p=0.004, 95% CI-0.35 to -0.07) in the PAH group, while the radial strain was preserved. All RV echocardiographic parameters and LV end-diastolic dimension, LV end-systolic volume in the PAH were affected significantly (p=0.002, 95% CI-19.91 to -4.46; p=0.01, 95% CI-8.44 to -2.77). However, only a weak correlation (p=0.05, r =-0.20) was found between tricuspid annular plane systolic excursion and LV Tei index.

Conclusion: RV pressure overload directly affects RV longitudinal systolic deformation further influences the interventricular septal and LV geometry, which impaired LV torsion.