Right atrial function in hypertensive patients: effects of antihypertensive therapy

Effect of different titration methods on right heart function and prognosis in patients with acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a common disease in intensive critical care(ICU), and the use of positive end-expiratory pressure(PEEP) during mechanical ventilation can increase the right heart afterload and eventually cause right heart dysfunction. For these factors causing acute cor pulmonale(ACP), especially inappropriate mechanical ventilation settings, it is important to explore the effect of PEEP on right heart function.

OBJECTIVE

To investigate the effects of three titration methods on right heart function and prognosis in patients with ARDS.

METHODS

Observational, prospective study in which ARDS patients were enrolled into three distinct PEEP-titration strategies groups: guide, transpulmonary pressure-oriented and driving pressure-oriented. Prognostic indicators, right heart systolic and diastolic echocardiographic function indices, ventilatory parameters, blood gas analysis results, and respiratory mechanics Monitoring indices were collated and analyzed statistically by STATA 15 software.

RESULTS

A total of 62 ARDS patients were enrolled into guide (G) group (n=40) for whom titrated PEEP values were 9±2cm H₂O, driving pressure-oriented (DPO) group (n=12) with titrated PEEP values of 10±2cm H₂O and transpulmonary pressure-oriented (TPO) group (n=10) with titrated PEEP values of 12±3cm H₂O. Values were significantly higher for TPO than for G (p=0.616) or DPO (p=0.011). Compliance was significantly increased after 72 h in the TPO and DPO groups compared with the G group (p<0.001). Mean airway pressure at end-inspiratory obstruction (p=0.047), tricuspid annular plane systolic excursion (TAPSE, p<0.001) and right ventricular area change fraction (RVFAC, p=0.049) were all higher in the TPO and DPO groups than in the G group. E/A indices were significantly better in the TPO group than in the G or DPO groups (p=0.046). No significant differences in 28 day mortality were found among the three groups. Multivariate logistic regression analysis revealed that lung compliance and transpulmonary pressure-oriented PEEP titration method was negatively correlated to the increase in right ventricular systolic dysfunction.

CONCLUSION

Transpulmonary pressure-oriented PEEP titration improves oxygenation and pulmonary function and causes less right heart strain when compared to other PEEP-titration methods during mechanical ventilation of ARDS patients.

Right ventricular diastolic dysfunction and failure: a review

Right ventricular diastolic dysfunction and failure (RVDDF) has been increasingly identified in patients with cardiovascular diseases, including heart failure and other diseases with cardiac involvement. It is unknown whether RVDDF exists as a distinct clinical entity; however, its presence and degree have been shown to be a sensitive marker of end-organ dysfunction related to multiple disease processes including systemic hypertension, pulmonary hypertension, heart failure, and endocrine disease. In this manuscript, we review issues pertaining to RVDDF including anatomic features of the right ventricle, physiologic measurements, RVDDF diagnosis, underlying mechanisms, clinical impact, and clinical management. Several unique features of RVDDF are also discussed.

Right Ventricular Myocardial Stiffness and Relaxation Components by Kinematic Model-Based Transtricuspid Flow Analysis in Children and Adolescents with Pulmonary Arterial Hypertension

We hypothesized that the kinematic model-based parameters obtained from the transtricuspid E-wave would be useful for evaluating the right ventricular diastolic property in pediatric pulmonary arterial hypertension (PAH) patients. The model was parametrized by stiffness/elastic recoil k, relaxation/damping c and load x. These parameters were determined as the solution of m⋅d²x/dt² + c⋅dx/dt + kx = 0, which is based on the theory that the E-wave contour is determined by the interplay of stiffness/restoring force, damping/relaxation force and load. The PAH group had a significantly higher k and c compared with the control group (182.5 ± 72.4 g/s vs. 135.7 ± 49.5 g/s², p = 0.0232, and 21.9 ± 6.5 g/s vs. 10.6 ± 5.2 g/s, p <0.0001, respectively). These results indicate that in the PAH group, the right ventricle had higher stiffness/elastic recoil and inferior cross-bridge relaxation. The present findings indicate the feasibility and utility of using kinematic model parameters to assess right ventricular diastolic function.

Possible beneficial effect of olmesartan medoxomil on left atrial function in patients with hypertension : noninvasive assessment by acoustic quantification

BACKGROUND AND OBJECTIVE

Hypertension alters the diastolic properties of the left ventricle and results in deterioration in the structure and function of the left atrium. We aimed to evaluate whether olmesartan medoxomil has an effect on left atrial function in hypertensive patients.

METHODS

Fifty hypertensive patients and 20 controls were included in the study. Hypertensive patients were treated with olmesartan medoxomil for 8 weeks. Before and after treatment, study participants were examined by acoustic quantification and tissue Doppler imaging. Left atrial reservoir function was assessed by end-diastolic volume (EDV), end-systolic volume (ESV), reservoir volume (RV) and peak filling rate (PFR). Left atrial booster pump function was assessed by atrial emptying volume (AEV), atrial emptying fraction (AEF) and peak atrial emptying rate (PAER). Left atrial conduit function was assessed by rapid emptying volume (REV), rapid emptying fraction (REF), REV/AEV ratio, and the ratio of peak rapid emptying rate and PAER (PRER/PAER).

RESULTS

Atrial RV and PFR were significantly increased in hypertensive subjects (48.30 +/- 19.28 mL vs 34.35 +/- 14.26 mL, p < 0.001; 267.26 +/- 126.52 mL/s vs 206.81 +/- 107.17 mL/s, p < 0.05) compared with controls, while the REV/AEV ratio was decreased in hypertensive patients compared with controls (2.86 +/- 0.85 vs 3.69 +/- 2.13, p < 0.001). After therapy with olmesartan medoxomil, atrial RV (48.30 +/- 19.28 mL vs 40.50 +/- 17.59 mL) and PFR decreased (267.26 +/- 126.52 mL/s vs 220.40 +/- 108.56 mL/s, p < 0.05) and the REV/AEV ratio increased (2.86 +/- 0.85 vs 3.14 +/- 0.43, p < 0.05) in hypertensive patients.

CONCLUSION

Our novel findings indicate that left atrial function is impaired in hypertensive patients, and that olmesartan medoxomil can improve left atrial function in this context. Our study also showed that acoustic quantification is useful for non-invasive evaluation of the benefits of treatment on left atrial function.