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Background: Pulmonary hypertension (PH) results in right ventricular (RV) dysfunction, subsequently leading to left ventricular (LV) impairment. The mechanism underlying ventricular interdependence is largely uninvestigated. Purpose: To explore the biventricular dysfunction and the ventricular interdependence in PH patients. Study Type: Retrospective. Population: One hundred and seven PH patients (mean pulmonary artery pressure >20 mmHg) and 72 age‐ and sex‐matched controls with cardiac magnetic resonance imaging (MRI) studies. Field Strength/Sequence: 3.0 T/balanced steady‐state free precession sequence. Assessment: LV and RV ejection fractions (EF) and RV and LV radial, circumferential, and longitudinal strains were assessed using commercial software. Strains were compared between controls, PH patients with preserved RVEF (RVEF ≥40%, N = 48), and PH patients with reduced RVEF (RVEF <40%, N = 59). Statistical Tests: Chi‐squared tests or Fisher's exact test, t tests or Mann–Whitney U test, one‐way ANOVA with Bonferroni's post hoc correction or Kruskal–Wallis test, Pearson or Spearman correlation, and multivariable linear regression analysis. A two‐tailed P < 0.05 was deemed statistically significant. Results: RV strain decreased sequentially from controls, through PH with preserved RVEF, to PH with reduced RVEF. PH patients with reduced RVEF had significantly lower LV strain, especially septal strain, and LV peak diastolic strain rate compared with both controls and PH patients with preserved RVEF. Multivariable analyses showed that RVEF was independently correlated with LV strain; furthermore, independent of RVEF, RV strain was significantly correlated with LV strain (LVGRS: β = 0.416; LVGCS: β = −0.371; LVGLS: β = 0.283). Data Conclusion: Subclinical impairment of RV function was found in PH with preserved RVEF. LV strain was impaired when RV was dysfunctional, which was associated with worsening RV strain. Therefore, while focusing on improving RV function, LV dysfunction in PH patients should also be monitored and treated early in order to slow the progression of the disease. Level of Evidence: 3 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

Background: The alteration of left atrial (LA) phasic function in subacute and chronic pulmonary embolism (PE) patients is unclear., Purpose: To investigate LA phasic strain and LA-right ventricular (RV) interaction in subacute and chronic PE patients with different degrees of obstruction by MRI-feature tracking (MRI-FT)., Study Type: Retrospective., Population: One hundred three PE patients (54 subacute [2 weeks to 3 months after initial symptoms], 49 chronic [>3 months after initial symptoms]) and 80 controls., Field Strength/sequence: 3.0 T/balanced steady state free precession sequence., Assessment: Patients were divided into mild (pulmonary artery obstruction index [PAOI] < 30%, N = 57), moderate (30% ≤ PAOI < 50%, N = 27), and severe (50% ≥ PAOI, N = 19) PE subgroups. LA reservoir, conduit, and active pump longitudinal strains (εs, εe, and εa) and strain rates (SRs, SRe, and SRa) and biventricular global strains were measured. Determinants of LA strains were investigated., Statistical Tests: ANOVA, t-tests, Mann-Whitney U tests, linear regression. P < 0.05 was considered statistically significant., Results: For both subacute and chronic PE patients, LA reservoir, conduit, and active pump strains and strain rates were significantly lower than in controls. However, there were no significant differences in LA strains between patients with subacute and chronic PE (P = 0.933, 0.625, and 0.630 for εs, εe, and εa). The severe PE subgroup had significantly higher εa and SRa than the mild and moderate PE subgroups. LA strains were significantly correlated with RV diameter and biventricular strains, and RV diameter (β = -6.836, -4.084, and -1.899 for εs, εe, and εa) was independently associated with LA strains after adjustment for other factors (R 2  = 0.627, 0.536, and 0.437 for εs, εe, and εa)., Data Conclusion: LA phasic function evaluated by MRI-FT was significantly impaired in subacute and chronic PE patients, and LA active pump function in the severe PE subgroup was higher than that in the mild and moderate PE subgroups. The independent association between RV diameter and LA strains demonstrates that RV diameter may be an important indicator for monitoring LA dysfunction in PE patients., Evidence Level: 3 TECHNICAL EFFICACY: Stage 3., (© 2024 International Society for Magnetic Resonance in Medicine.)