The functional relevance of right atrial (RA) function in pulmonary hypertension (PH) remains incompletely understood. The purpose of this study was to explore the correlation of cardiac magnetic resonance (CMR) feature tracking-derived RA phasic function with invasively measured pressure-volume (P-V) loop-derived right ventricular (RV) end-diastolic elastance ( E_ed) and RV-arterial coupling [ratio of end-systolic elastance to arterial elastance ( E_es/ E_a)]. In 54 patients with severe PH, CMR was performed within 24 h of diagnostic right heart catheterization and P-V measurements. RA phasic function was assessed by CMR imaging of RA reservoir, passive, and active strain. The association of RA phasic function with indexes of RV function was evaluated by Spearman’s rank correlation and linear regression analyses. Median [interquartile range] RA reservoir strain, passive strain, and active strain were 19.5% [11.0–24.5], 7.0% [4.0–12.0], and 13.0% [7.0–18.5], respectively. E_es/ E_a was 0.73 [0.48–1.08], and E_ed was 0.14 mmHg/mL [0.05–0.22]. RV diastolic impairment [RV end-diastolic pressure (EDP) and E_ed] was correlated with RA phasic function, but E_a and E_es were not. In addition, RA phasic function was correlated with inferior vena cava diameter. In multivariate linear regression analysis, adjusting for key P-V loop indexes, E_ed and EDP remained significantly associated with RA phasic function. We conclude that RA phasic function is altered in relation to impaired diastolic function of the chronically overloaded right ventricle and contributes to backward venous flow and systemic congestion. These results call for more attention to RA function in the management of patients with PH. NEW & NOTEWORTHY There is growing awareness of the importance of the right atrial (RA)-right ventricular (RV) axis in pulmonary hypertension (PH). Our results uncover alterations in RA phasic function that are related to depressed RV lusitropic function and contribute to backward venous return and systemic congestion in chronic RV overload. Assessment of RA function should be part of the management and follow-up of patients with PH.

Cardiopulmonary exercise testing (CPET) is an important tool for assessing functional capacity and prognosis in pulmonary arterial hypertension (PAH). However, the associations of CPET parameters with the adaptation of right ventricular (RV) function to afterload remain incompletely understood.In this study, 37 patients with PAH (idiopathic in 31 cases) underwent single-beat pressure–volume loop measurements of RV end-systolic elastance (Ees), arterial elastance (Ea) and diastolic elastance (Eed). Pulmonary arterial stiffness was assessed by magnetic resonance imaging. The results were correlated to CPET variables. The predictive relevance of RV function parameters for clinically relevant ventilatory inefficiency, defined as minute ventilation/carbon dioxide production (V′_E/V′CO₂) slope >48, was evaluated using logistic regression analysis.The median (interquartile range) of theV′_E/V′CO₂slope was 42 (32–52) and theV′_E/V′CO₂nadir was 40 (31–44). The mean±sdof peak end-tidal carbon dioxide tension (PETCO₂) was 23±8 mmHg. Ea, Eed and parameters reflecting pulmonary arterial stiffness (capacitance and distensibility) correlated with theV′_E/V′CO₂slope,V′_E/V′CO₂nadir,PETCO₂and peak oxygen pulse. RV Ees and RV–arterial coupling as assessed by the Ees/Ea ratio showed no correlations with CPET parameters. Ea (univariate OR 7.28, 95% CI 1.20–44.04) and Eed (univariate OR 2.21, 95% CI 0.93–5.26) were significantly associated with ventilatory inefficiency (p<0.10).Our data suggest that impaired RV lusitropy and increased afterload are associated with ventilatory inefficiency in PAH.

Deep learning–based cardiac cine sequences performed over three cardiac cycles led to substantially reduced acquisition time, while no differences in image quality and volumetric results compared with a standard clinical sequence could be detected.

Right ventricular (RV) dyssynchrony has been related to outcome in pulmonary arterial hypertension. Prospectively, we performed echocardiography with measurement of right ventricular dyssynchrony and pressure–volume loop catheterization in 27 pulmonary arterial hypertension patients. Afterload and diastolic function emerged as determinates of wall stress, which results in dyssynchrony.

Background: Accurate plane positioning is important for high‐quality cardiac MRI images but requires specialized training, limiting accessibility. Purpose: To evaluate an automated plane positioning tool and compare it with manual planning. Study Type: Prospective. Population: Fifty‐seven healthy volunteers (28 males; median age 42 years) and 20 consecutive patients (15 males; median age 61 years) scheduled for clinical cardiac MRI. Field Strength/Sequence: Steady state free precession cine sequence at 1.5 T. Assessment: In volunteers, short‐axis (SAX), 2‐chamber (2CH), 3‐chamber (3CH), and 4‐chamber (4CH) cine images were acquired using both automated and manual prescription. Two blinded radiologists (5 and 6 years of clinical cardiac MRI experience) rated plane quality on a Likert scale (1 = nondiagnostic to 5 = excellent ). Mean plane angle differences between manual and automated prescriptions were calculated. Left and right ventricular end‐systolic volume (ESV), end‐diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF) were compared. In patients, the number of required manual corrections to automated prescriptions was recorded. Statistical Analysis: Wilcoxon matched‐pairs signed rank tests and Bland–Altman analyses, significance level at p ≤ 0.05. Results: Automated plane positioning was successful in all volunteers. Image plane quality did not differ significantly between automated (mean score 4.64) and manual prescription (4.62, p = 0.812). Mean angle differences were 6.7° ± 4.3° (SAX), 10.3° ± 5.8° (2CH), 8.9° ± 5.1° (3CH), and 8.0° ± 4.8° (4CH). Volumetric parameters showed no significant differences between both planning methods with mean biases being −0.5 mL, p = 0.305 (LVEDV), 0.5 mL, p = 0.683 (LVESV), −1.0 mL, p = 0.168 (LVSV) and 0.4%, and p = 0.215 (LVEF). In patients, 8.8% (7/80) of automatically prescribed planes required minor corrections; 91.2% (73/80) were accepted without adjustments. Data Conclusion: Automated plane positioning for cardiac MRI may provide high‐quality images and accurate volumetric assessment comparable to manual planning. Evidence Level: 2. Technical Efficacy: Stage 2.

Background/Objectives: This study aimed to compare changes in functional and strain parameters in young and old mice using cardiac MRI before and shortly after myocardial infarction. Methods: In this prospective experimental study, 7 young mice and 10 old mice underwent a cardiac MRI 5 days before and 2 days after myocardial infarction by LAD ligation. Functional parameters such as EDV, ESV, EF, SV, and Strain were determined. Results: EDV in the young mice before LAD ligation was significantly lower than in the old mice (p-value 0.002). EDV significantly increased after infarction in both groups. ESV was significantly lower in young mice before infarction than in old mice (9.7 ± 2.6 vs. 13.8 ± 3.9 [µL], p = 0.029). After infarction, the mean value was still lower but no longer significant. There was no significant difference between young and old mice either before or after infarction for the EF. But again, the decrease was significant for both groups (old: p < 0.0001 and young: p = 0.0009). Each global strain showed deterioration after infarction. This difference was significant in both subgroups for young mice and old mice for each strain. There were no differences either before or after infarction between the young and old mice. Conclusions: There were differences in functional parameters between young and old mice in EDV, SV, and CO. Changes in strain parameters in the acute phase post-myocardial infarction did not differ significantly between young and old mice, while there was a clear deterioration in strain parameters after infarction in both groups.