Comprehensive Functional Assessment of Right-Sided Heart Using Speckle Tracking Strain for Patients with Pulmonary Hypertension

Right Atrial Strain in Pediatric Pulmonary Hypertension-A Prospective Observational Study

Right ventricular (RV) afterload due to elevated pulmonary arterial (PA) pressure in pulmonary hypertension (PH) causes long-term right atrial (RA) remodeling and dysfunction. RA function has been shown to correlate with PA pressures and outcome in both adult and pediatric patients with PH. We studied the role of RA strain in estimating PA pressures in congenital heart disease (CHD)-associated PH. Children below 12 years undergoing elective repair of CHD with left-to-right shunts and echocardiographic evidence of PH were included. RA reservoir, conduit and contractile strain along with conventional measures of RV function and PA pressure were measured using transthoracic echocardiography after induction of anaesthesia. Pre-and post-repair invasive PA pressures were measured after surgical exposure. 51 children with a median age of 24 months (range 4-144 months) were included, most of whom were undergoing VSD closure. Contractile RA strain showed good correlation with pre-repair systolic PA pressure in mmHg (r = 0.59, 95%CI 0.37-0.75) or expressed as a percentage of SBP (r = 0.67, 95%CI 0.49-0.80). It also predicted persistent postoperative PH as well as pre-repair pulmonary artery acceleration time and right ventricular systolic pressure measured from tricuspid regurgitation jet. The trends of correlation observed suggest a possible prognostic role of RA strain in ACHD with PH and potential utility in its echocardiographic assessment. The observed findings merit deeper evaluation in larger cohorts.

Echocardiographic evaluation of right ventricular diastolic function in pulmonary hypertension

Background

Right ventricular (RV) diastolic dysfunction may be prognostic in pulmonary hypertension (PH). However, its assessment is complex and relies on conductance catheterisation. We aimed to evaluate echocardiography-based parameters as surrogates of RV diastolic function, provide validation against the gold standard, end-diastolic elastance (Eed), and define the prognostic impact of echocardiography-derived RV diastolic dysfunction.

Methods

Patients with suspected PH who underwent right heart catheterisation including conductance catheterisation were prospectively recruited. In this study population, an echocardiography-based RV diastolic function surrogate was derived. Survival analyses were performed in patients with precapillary PH in the Giessen PH Registry, with external validation in patients with pulmonary arterial hypertension at Sapienza University (Rome).

Results

In the derivation cohort (n=61), the early/late diastolic tricuspid inflow velocity ratio (E/A) and early tricuspid inflow velocity/early diastolic tricuspid annular velocity ratio (E/e') did not correlate with Eed (p>0.05). Receiver operating characteristic analysis revealed a large area under the curve (AUC) for the peak lateral tricuspid annulus systolic velocity/right atrial area index ratio (S'/RAAi) to detect elevated Eed (AUC 0.913, 95% confidence interval (CI) 0.839-0.986) and elevated end-diastolic pressure (AUC 0.848, 95% CI 0.699-0.998) with an optimal threshold of 0.81 m2·s-1·cm-1. Subgroup analyses demonstrated a large AUC in patients with preserved RV systolic function (AUC 0.963, 95% CI 0.882-1.000). Survival analyses confirmed the prognostic relevance of S'/RAAi in the Giessen PH Registry (n=225) and the external validation cohort (n=106).

Conclusions

Our study demonstrates the usefulness of echocardiography-derived S'/RAAi for noninvasive assessment of RV diastolic function and prognosis in PH.

Right atrial reservoir strain and right ventricular strain improves in patients recovered from hospitalisation for non-severe COVID-19

PURPOSE

Those hospitalised with coronavirus disease 2019 (COVID-19) have recently been shown to have impaired right ventricular (RV) strain, but data about the course of heart function after discharge are limited. Our aim was to compare right ventricular strain and right atrial reservoir strain (RASr) associated with COVID-19 between acute disease (during hospitalisation) and follow-up (after discharge).

METHODS

In this retrospective single-center study, we analysed the echocardiograms of 43 patients hospitalised for non-severe COVID-19 between December 2020 and March 2021, undergoing echocardiography both during and after hospitalisation. In addition to conventional echocardiographic parameters, we applied 2-dimensional speckle tracking to obtain RV global longitudinal strain (RV-GLS), RV free wall strain (RV-FWS), and RASr.

RESULTS

Mean (standard deviation) age of the study population was 50 (9) years, and 18 (42%) of the participants were women. Median duration between exams was 6 months (range, 5-7 months). Both mean RV-GLS and mean RV-FWS significantly increased at follow-up (-20.8 [3.8] vs. -23.5 [2.8], p < 0.001 and -23.3 [4.2] vs. -28.2 [2.8], p < 0.001; respectively), and RASr significantly improved as well (-32.3 [6.6] vs. -41.9 [9.8], p < 0.001).

CONCLUSION

In patients hospitalised for non-severe COVID-19 pneumonia, RV-GLS, RV-FWS, and RASr improved significantly between acute disease and 6 months after discharge.

Training and clinical testing of artificial intelligence derived right atrial cardiovascular magnetic resonance measurements

BACKGROUND

Right atrial (RA) area predicts mortality in patients with pulmonary hypertension, and is recommended by the European Society of Cardiology/European Respiratory Society pulmonary hypertension guidelines. The advent of deep learning may allow more reliable measurement of RA areas to improve clinical assessments. The aim of this study was to automate cardiovascular magnetic resonance (CMR) RA area measurements and evaluate the clinical utility by assessing repeatability, correlation with invasive haemodynamics and prognostic value.

METHODS

A deep learning RA area CMR contouring model was trained in a multicentre cohort of 365 patients with pulmonary hypertension, left ventricular pathology and healthy subjects. Inter-study repeatability (intraclass correlation coefficient (ICC)) and agreement of contours (DICE similarity coefficient (DSC)) were assessed in a prospective cohort (n = 36). Clinical testing and mortality prediction was performed in n = 400 patients that were not used in the training nor prospective cohort, and the correlation of automatic and manual RA measurements with invasive haemodynamics assessed in n = 212/400. Radiologist quality control (QC) was performed in the ASPIRE registry, n = 3795 patients. The primary QC observer evaluated all the segmentations and recorded them as satisfactory, suboptimal or failure. A second QC observer analysed a random subcohort to assess QC agreement (n = 1018).

RESULTS

All deep learning RA measurements showed higher interstudy repeatability (ICC 0.91 to 0.95) compared to manual RA measurements (1st observer ICC 0.82 to 0.88, 2nd observer ICC 0.88 to 0.91). DSC showed high agreement comparing automatic artificial intelligence and manual CMR readers. Maximal RA area mean and standard deviation (SD) DSC metric for observer 1 vs observer 2, automatic measurements vs observer 1 and automatic measurements vs observer 2 is 92.4 ± 3.5 cm2, 91.2 ± 4.5 cm2 and 93.2 ± 3.2 cm2, respectively. Minimal RA area mean and SD DSC metric for observer 1 vs observer 2, automatic measurements vs observer 1 and automatic measurements vs observer 2 was 89.8 ± 3.9 cm2, 87.0 ± 5.8 cm2 and 91.8 ± 4.8 cm2. Automatic RA area measurements all showed moderate correlation with invasive parameters (r = 0.45 to 0.66), manual (r = 0.36 to 0.57). Maximal RA area could accurately predict elevated mean RA pressure low and high-risk thresholds (area under the receiver operating characteristic curve artificial intelligence = 0.82/0.87 vs manual = 0.78/0.83), and predicted mortality similar to manual measurements, both p < 0.01. In the QC evaluation, artificial intelligence segmentations were suboptimal at 108/3795 and a low failure rate of 16/3795. In a subcohort (n = 1018), agreement by two QC observers was excellent, kappa 0.84.

CONCLUSION

Automatic artificial intelligence CMR derived RA size and function are accurate, have excellent repeatability, moderate associations with invasive haemodynamics and predict mortality.

Temporal trends in right heart strain in patients undergoing pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension

BACKGROUND

Pulmonary thromboendarterectomy (PTE) is a curative procedure for chronic thromboembolic pulmonary hypertension (CTEPH). Right ventricular free wall strain (RV FWS) and right atrial strain (RAS) are not well studied in a CTEPH population. We sought to determine temporal trends in RAS and RV FWS in patients post-PTE.

METHODS

28 patients undergoing PTE for CTEPH were prospectively enrolled in a surgical database. Comprehensive echocardiographic assessment of the right heart was performed including RV FWS, right atrial volume, and the three components of RAS: reservoir, conduit, and booster strain.

RESULTS

Patients undergoing PTE demonstrated improvement in NYHA functional class (P < 0.001). Hemodynamic assessment showed improvement in mean pulmonary artery pressure from 49.7 ± 8.5 mm Hg to 23.9 ± 6.5 mm Hg (P < 0.001) and pulmonary vascular resistance decreased from 7.8 ± 3.2 wu to 2.4 ± 1.3 wu (P < 0.001). Tricuspid annular plane systolic excursion (TAPSE) and lateral S` declined immediately post-op. RV FWS improved from -14.4 ± 4% to -19 ± 3.4% post-op and -21.2 ± 4.7% at long-term follow-up (P < 0.001). Improvement in RV FWS post-op was driven primarily by increases in the apical and mid segments. RA volume declined significantly during the study period. RA reservoir and conduit strain improved after PTE.

CONCLUSION

Patients undergoing PTE for CTEPH had significant improvement in right heart hemodynamics immediately post-op. Traditional echo metrics of RV performance including TAPSE and lateral S` did not improve. RV FWS improved, which was driven by changes in the apical and mid segments. This highlights that RV FWS is a viable and useful metric to follow in CTEPH patients post-PTE.

Repeatability, reproducibility, and reference intervals for indices of right atrial longitudinal strain derived from speckle-tracking echocardiography in healthy dogs

OBJECTIVE

To determine repeatability, reproducibility, and reference intervals of indices of right atrial longitudinal strain (RALS) derived from speckle-tracking echocardiography (STE) in dogs without heart disease.

ANIMALS

110 client-owned dogs and 10 laboratory Beagles.

PROCEDURES

To determine intraobserver within-day (repeatability) and interobserver (reproducibility) coefficients of variation, RALS during ventricular systole (ϵS), ventricular early diastole (ϵE), and atrial systole (ϵA), as derived with STE, were obtained by 2 investigators for 5 randomly selected client-owned dogs and analyzed by linear regression. Reference intervals were estimated from the results of all dogs. Correlations between RALS indices (ϵS, ϵE, and ϵA) and sex, age, body weight, heart rate, and blood pressure were determined.

RESULTS

RALS derived from STE showed good intraobserver within-day repeatability and interobserver reproducibility, with coefficients of variation of < 20%. Both ϵS and ϵE were significantly negatively correlated with age, but ϵA was not correlated with age. Indices were not correlated with sex, body weight, or blood pressure.

CONCLUSIONS AND CLINICAL RELEVANCE

RALS indices derived from STE were repeatable and reproducible and were affected by the age of dogs without heart disease. Age should be considered in the interpretation of RALS indices in clinical settings. Further studies are needed to apply RALS indices for assessing dogs with heart disease.

Atrial performance in healthy subjects following high altitude exposure at 4100 m: 2D speckle-tracking strain analysis

High altitude (HA) exposure has been considered as a cardiac stress and might impair ventricular diastolic function. Atrial contraction is involved in ventricular passive filling, however the atrial performance to HA exposure is poorly understood. This study aimed to evaluate the effect of short-term HA exposure on bi-atrial function. Physiological and 2D-echocardiographic data were collected in 82 healthy men at sea level (SL, 400 m) and 4100 m after an ascent within 7 days. Atrial function was measured using volumetric and speckle-tracking analyses during reservoir, conduit and contractile phases of cardiac cycle. Following HA exposure, significant decreases of reservoir and conduit function indexes were observed in bi-atria, whereas decreases of contractile function indexes were observed in right atrium (RA), estimated via RA active emptying fraction (SL 41.7 ± 13.9% vs. HA 35.4 ± 12.2%, p = 0.001), strain during the contractile phase [SL 13.5 (11.4, 17.8) % vs. HA 12.3 (9.3, 15.9) %, p = 0.003], and peak strain rate during the contractile phase [SL − 1.76 (− 2.24, − 1.48) s⁻¹ vs. HA − 1.57 (− 2.01, − 1.23) s⁻¹, p = 0.002], but not in left atrium (LA). In conclusion, short-term HA exposure of healthy individuals impairs bi-atrial performance, mostly observed in RA. Especially, atrial contractile function decreases in RA rather than LA, which seems not to compensate for decreased ventricular filling after HA exposure. Our findings may provide a novel evidence for right-sided heart dysfunction to HA exposure.

Normal Values of Right Atrial Size and Function According to Age, Sex, and Ethnicity: Results of the World Alliance Societies of Echocardiography Study

BACKGROUND

The World Alliance Societies of Echocardiography study is a multicenter, international, prospective, cross-sectional study whose aims were to evaluate healthy adult individuals to establish age- and sex-normative values of echocardiographic parameters and to determine whether differences exist among people from different countries and of different ethnicities. The present report focuses on two-dimensional (2D) and three-dimensional (3D) right atrial (RA) size and function.

METHODS

Transthoracic 2D and 3D echocardiographic images were obtained in 2,008 healthy adult individuals evenly distributed among subgroups according to sex (1,033 men, 975 women) and age 18 to 40 years (n = 854), 41 to 65 years (n = 653), and >65 years (n = 501). For ethnicity, 34.9% were white, 41.6% Asian, and 9.7% black. Images were analyzed in a core laboratory according to current American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. RA measurements included 2D dimensions, 2D and 3D RA volumes (RAVs) indexed to body surface area (BSA), emptying fraction (EmF), and global longitudinal strain, including total/reservoir, passive/conduit, and active/contractile phases. Differences among age and sex categories and among countries were also examined.

RESULTS

RAVs were larger in men (even after BSA indexing), while 3D total EmF and global longitudinal strain magnitudes were higher in women. For both sexes, there were no significant age-related differences in 2D RAV measurements, but 3D RAV values differed minimally with age, remaining significant after BSA indexing. RA total EmF and reservoir strain and passive EmF and conduit strain magnitude were lower in older groups for both sexes. Interestingly, whereas RA active EmF increased with age, contractile strain magnitude decreased. Considerable geographic variations were identified: Asians of both sexes had significantly lower BSA than non-Asians, and their 2D and 3D end-systolic RAVs were significantly smaller even after BSA indexing. Of note, 2D end-systolic RAVs in this group were considerably lower than normal values provided in the current guidelines.

CONCLUSIONS

There is significant sex, age, and geographic variability in normal RA size and function parameters. Current guideline-recommended normal ranges for RA size and function parameters should be adjusted geographically on the basis of the results of this study.

Diagnostic utility of right atrial reservoir strain to identify elevated right atrial pressure in heart failure

BACKGROUND

Accurate non-invasive estimation of right atrial pressure (RAP) is essential to assess volume status and optimize therapy in heart failure (HF). This study aimed to evaluate the utility of right atrial reservoir strain (RASr) assessed by speckle-tracking echocardiography to identify elevated RAP in HF and compare diagnostic performance with estimated RAP employing inferior vena cava size and collapsibility (RAP_IVC), in addition to RA area.

METHOD

Association between RASr and invasive RAP (RAP_Invasive) was examined in 103 HF subjects that underwent standard echocardiography with speckle-tracking strain analysis directly followed by right heart catheterization. The discriminatory ability of RASr to identify RAP_Invasive > 7 mmHg was evaluated and compared with RAP_IVC and RA area.

RESULTS

RASr demonstrated association with RAP_Invasive (β = -0.41, p < 0.001) and was an independent predictor when adjusted for potential confounders (β = -0.25, p < 0.001). Further, RASr showcased strong discriminatory ability to identify subjects with RAP_Invasive > 7 mmHg (AUC = 0.78; 95% CI 0.68-0.87; p < 0.001). At a cut-off value of -15%, RASr displayed 78% sensitivity and 72% specificity to identify elevated RAP_Invasive. In comparison, RAP_IVC (AUC = 0.71; 95% CI 0.61-0.81; p < 0.001) demonstrated 89% sensitivity and 32% specificity with high false positive rate. RA area (AUC = 0.66; 95% CI 0.55-0.76, p = 0.005) displayed 64% sensitivity and 53% specificity.

CONCLUSIONS

RASr demonstrates good ability to identify elevated RAP and relatively stronger diagnostic performance when compared with conventional non-invasive measures. RASr may be useful as a novel noninvasive estimate of RAP in HF management.

Associations of 2D speckle tracking echocardiography-based right heart deformation parameters and invasively assessed hemodynamic measurements in patients with pulmonary hypertension

BACKGROUND

We aimed to evaluate associations of right atrial (RA) and right ventricular (RV) strain parameters assessed by 2D speckle tracking echocardiography (2D STE) with invasively measured hemodynamic parameters in patients with and without pulmonary hypertension (PH).

METHODS

In this study, we analyzed 78 all-comer patients undergoing invasive hemodynamic assessment by left and right heart catheterization. Standard transthoracic echocardiographic assessment was performed under the same hemodynamic conditions. RA and RV longitudinal strain parameters were analyzed using 2D STE. PH was defined as invasively obtained mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest and was further divided into pre-capillary PH (pulmonary capillary wedge pressure [PCWP] ≤ 15 mmHg), post-capillary PH (PCWP > 15 mmHg) and combined PH (PCWP > 15 mmHg and difference between diastolic PAP and PCWP of ≥7 mmHg). Correlation analyses between variables were calculated with Pearson's or Spearman's correlation coefficient as applicable.

RESULTS

Out of 78 patients, 45 presented with PH. Within the PH group, 39 had post-capillary, five had combined pre- and post-capillary PH, and one had pre-capillary PH. Patients with PH had a significantly increased RA area (PH 22.0 ± 9.2 cm², non-PH 17.3 ± 10.7 cm²; p = 0.003) and end-systolic RV area (PH 14.7 ± 6.1, non-PH 11.9 ± 4.8 cm²; p = 0.022). RV mid strain was significantly reduced in PH (PH -17.4 ± 7.8, non-PH: - 21.6 ± 5.5; p = 0.019). Average peak systolic RA strain (RAS) and average peak systolic RV strain (RVS) showed a significant association with mPAP (r = - 0.470, p = 0.001 and r = 0.490, p = 0.001, respectively) and with PCWP (r = - 0.296, p = 0.048 and r = 0.365, p = 0.015, respectively) in patients with PH. Furthermore, RV apical, mid and basal strain as well as RV free wall strain showed moderate associations with mPAP. In patients without PH, there were no associations detectable between RA or RV strain parameters and mPAP and PCWP.

CONCLUSION

In an all-comer cohort, RA and RV strain parameters showed significant associations with invasively assessed mPAP and PCWP in patients with predominantly post-capillary PH. These associations may be useful in clinical practice to assess the impact of post-capillary PH on myocardial right heart function.

Right ventricular function correlates of right atrial strain in pulmonary hypertension: a combined cardiac magnetic resonance and conductance catheter study

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 ( Eed) and RV-arterial coupling [ratio of end-systolic elastance to arterial elastance ( Ees/ Ea)]. 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. Ees/ Ea was 0.73 [0.48–1.08], and Eed was 0.14 mmHg/mL [0.05–0.22]. RV diastolic impairment [RV end-diastolic pressure (EDP) and Eed] was correlated with RA phasic function, but Ea and Ees 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, Eed 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.

Association of peak atrial longitudinal strain with atrial fibrillation recurrence in patients with chronic lung diseases following radiofrequency ablation

BACKGROUND

Strain was shown associated with atrial fibrillation (AF) recurrence after radiofrequency ablation (RFA), but data on AF patients complicated with chronic lung diseases (CLD) were rare.

AIM

This study was designed to evaluate the relationship of baseline atrial function with AF recurrence in these patients using speckle-tracking echocardiography.

METHODS

Average strain values (median: 2 days before RFA) were calculated for 87 AF patients (Mean age: 61.91 years, male: 71.26%) with CLD undergoing RFA from 2013 to 2014. Of these patients, 25 (28.74%) experienced AF recurrence during a mean follow up of 10.3 months.

RESULTS

Peak right atrial longitudinal strain (R-PALS) was associated with peak left atrial longitudinal strain (L-PALS, Standardised β = 0.45, P < 0.001) in multivariate linear regression. Multivariate Cox regression analysis showed R-PALS was associated with AF recurrence (hazard ratio, 0.86; 95% confidence interval (CI), 0.78-0.96, P = 0.005) in CLD. Patients with R-PALS ≥14.69% had higher AF free rate compared with R-PALS<14.69% using Kaplan-Meier analysis (log-rank, P < 0.001). R-PALS had similar C-index compared to L-PALS (difference: 0.03, 95%CI: -0.06-0.12, P = 0.53) and combined R-PALS and L-PALS (difference: 0.005, 95%CI: -0.04-0.05, P = 0.84) associated with AF recurrence in CLD.

CONCLUSION

R-PALS, L-PALS and combined R-PALS and L-PALS are important factors associated with AF recurrence following RFA in patients with CLD.

Echocardiography during preload stress for evaluation of right ventricular contractile reserve and exercise capacity in pulmonary hypertension

OBJECTIVES

Pulmonary hypertension (PH) is characterized by marked and sustained elevation of pulmonary vascular resistance and pulmonary artery pressure, and subsequent right-sided heart failure. Right ventricular (RV) function and exercise capacity have been recognized as important prognostic factors for PH. Our aim was to investigate RV contractile reserve and exercise capacity during a leg-positive pressure (LPP) maneuver.

METHODS

The study population comprised 43 PH patients and 17 normal controls. All patients underwent echocardiography at rest and during LPP stress. Exercise capacity was assessed by 6-minute walk distance for PH patients. RV relative wall thickness was calculated from dividing by RV free wall thickness by basal RV linear dimensions at end-diastole. RV function was calculated by averaging peak speckle-tracking longitudinal strain from the RV free wall. RV contractile reserve was assessed as the difference in RV free wall strain at rest and during LPP stress. Changes in left ventricular stroke volume (ΔSV) during LPP stress were also calculated.

RESULTS

ΔSV and RV contractile reserve of PH patients were significantly lower than of controls (3.6 ± 6.0 mL vs 8.5 ± 2.3 mL, and 8.2 ± 11.9% vs 14.5 ± 6.6%; both P < 0.01). RV contractile reserve of PH patients with ΔSV <3.3 mL was significantly lower than of PH patients with ΔSV >3.3 mL (3.9 ± 13.2% vs 12.3 ± 8.9%; P = 0.02). ΔSV had also significant correlation with 6-minute walk distance (r = 0.42, P = 0.006). Multivariate regression analysis showed that RV relative wall thickness was an independent determinant parameter of ΔSV during LPP stress for PH patients (β = 3.2, P = 0.003).

CONCLUSIONS

Preload stress echocardiography in response to LPP maneuver, a noninvasive and easy-to-use procedure for routine clinical use, proved to be useful for the assessment of RV contractile reserve and exercise capacity of PH patients.

Right atrial mechanics provide useful insight in pediatric pulmonary hypertension

Right atrial (RA) mechanics have been studied infrequently in children in the past due to technical constraints. With the advent of strain imaging, RA physiology can now be studied in greater detail. The principal aim of this study was to describe functional changes in right heart mechanics of children with idiopathic pulmonary arterial hypertension (PAH), by using new applications of RA strain. In this retrospective study, we evaluated RA mechanics of 20 patients (age range = 3-23 years) with PAH and 18 control patients. RA longitudinal strain (RALS) and longitudinal displacement (LD) were calculated by speckle-tracking echocardiography. RALS was plotted against LD, producing a characteristic strain-displacement (S-D) loop. Standard indices of right heart function and right heart catheterization data were obtained. Patients were clinically subdivided into "compensated" and "decompensated" PAH. A chart review was performed to identify patients who subsequently developed adverse outcomes, including death, awaiting or received lung and/or heart transplantation. RALS was significantly lower in decompensated PAH compared with both controls and compensated PAH. Area enclosed by S-D loops differed significantly between the compensated and decompensated PAH subgroups (5.33 [3.90-9.44] versus 1.83 [1.17-2.36], P < 0.05). S-D loop area and RALS possessed high sensitivity and specificity compared to other parameters for identifying children with PAH who subsequently developed adverse outcomes. In particular, their sensitivities and specificities were greatly superior compared to those of tricuspid annular plane systolic excursion (TAPSE). RALS may represent a useful metric for assessing right ventricular (RV) dysfunction. S-D loops, composed over an entire cardiac cycle, may present useful, composite information regarding both systolic and diastolic right heart function. RA mechanics may serve as useful tools for identifying patients with more severe PAH, who are at risk for future adverse outcomes associated with RV failure.

Right Atrial Deformation in Predicting Outcomes in Pediatric Pulmonary Hypertension

BACKGROUND

Elevated right atrial (RA) pressure is a risk factor for mortality, and RA size is prognostic of adverse outcomes in pulmonary hypertension (PH). There is limited data on phasic RA function (reservoir, conduit, and pump) in pediatric PH. We sought to evaluate (1) the RA function in pediatric PH patients compared with controls, (2) compare the RA deformation indices with Doppler indices of diastolic dysfunction, functional capacity, biomarkers, invasive hemodynamics, and right ventricular functional indices, and (3) evaluate the potential of RA deformation indices to predict clinical outcomes.

METHODS AND RESULTS

Sixty-six PH patients (mean age 7.9±4.7 years) were compared with 36 controls (7.7±4.4 years). RA and right ventricular deformation indices were obtained using 2-dimensional speckle tracking (2DCPA; TomTec, Germany). RA strain, strain rates, emptying fraction, and right ventricular longitudinal strain were measured. RA function was impaired in PH patients versus controls (P<0.001). There were significant associations between RA function with invasive hemodynamics (P<0.01). RA reservoir, pump function, the rate of RA filling, and atrial minimum volume predicted adverse clinical outcomes (hazard ratio [HR], 0.15; confidence interval [CI], 0.03-0.73; P<0.01; HR, 0.05; CI, 0.003-0.43; P<0.004; HR, 0.04; CI, 0.006-0.56; P<0.01; and HR, 8.6; CI, 1.6-37.2; P<0.01, respectively).

CONCLUSIONS

RA deformation properties are significantly altered in pediatric PH patients. Progressive worsening of RA reservoir and conduit functions is related to changes in right ventricular diastolic dysfunction. RA reservoir function, pump function, the rate of atrial filling, and atrial minimum volume emerged as outcome predictors in pediatric PH.

Non-invasive imaging of global and regional cardiac function in pulmonary hypertension

Pulmonary hypertension (PH) is a progressive illness characterized by elevated pulmonary artery pressure; however, the main cause of mortality in PH patients is right ventricular (RV) failure. Historically, improving the hemodynamics of pulmonary circulation was the focus of treatment; however, it is now evident that cardiac response to a given level of pulmonary hemodynamic overload is variable but plays an important role in the subsequent prognosis. Non-invasive tests of RV function to determine prognosis and response to treatment in patients with PH is essential. Although the right ventricle is the focus of attention, it is clear that cardiac interaction can cause left ventricular dysfunction, thus biventricular assessment is paramount. There is also focus on the atrial chambers in their contribution to cardiac function in PH. Furthermore, there is evidence of regional dysfunction of the two ventricles in PH, so it would be useful to understand both global and regional components of dysfunction. In order to understand global and regional cardiac function in PH, the most obvious non-invasive imaging techniques are echocardiography and cardiac magnetic resonance imaging (CMRI). Both techniques have their advantages and disadvantages. Echocardiography is widely available, relatively inexpensive, provides information regarding RV function, and can be used to estimate RV pressures. CMRI, although expensive and less accessible, is the gold standard of biventricular functional measurements. The advent of 3D echocardiography and techniques including strain analysis and stress echocardiography have improved the usefulness of echocardiography while new CMRI technology allows the measurement of strain and measuring cardiac function during stress including exercise. In this review, we have analyzed the advantages and disadvantages of the two techniques and discuss pre-existing and novel forms of analysis where echocardiography and CMRI can be used to examine atrial, ventricular, and interventricular function in patients with PH at rest and under stress.

Echocardiography in the Assessment of Patients with Rheumatologic Diseases

Cardiovascular disease is an important extra-articular manifestation of rheumatologic diseases leading to considerable mortality and morbidity. Echocardiography emerges as a useful non-invasive technique for the screening and evaluation of cardiac involvement in these patients. With the technological advancement in echocardiographic techniques, we have gained a greater appreciation of the prevalence and nature of the cardiac involvement in these patients, as detection of subclinical disease is increasingly feasible. This review discusses cardiac involvement in patients with rheumatoid arthritis, systemic lupus erythematosus, anti-phospholipid antibody syndrome, systemic sclerosis and ankylosing spondylitis, and the role of different echocardiographic modalities in their evaluation.

The Association of Functional Capacity With Right Atrial Deformation in Patients With Pulmonary Arterial Hypertension: A Study With Two-Dimensional Speckle Tracking

BACKGROUND

The purpose of this study was to assess right atrial (RA) myocardial mechanics in pulmonary hypertension (PH) patients using two-dimensional speckle tracking (2D-STE), and define the relationship between RA function and exercise capacity in PH patients.

METHODS

Thirty-eight consecutive PH patients were studied and compared with a control group of 25 healthy volunteers. Peak atrial longitudinal strain (PALS), RA strain rate were measured in all subjects. PALS values were obtained by averaging all segments (global PALS), and by averaging segments measured in the four-chamber view.

RESULTS

Right atrial PALS was significantly lower in PH patients than in controls, and gradually reduced with the development of cardiac insufficiency. A significantly positive correlation between global PALS and 6-minute walk distance (6MWD) was found (p=0.003). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.979) and excellent sensitivity and specificity of 86.8% and 84%, respectively, to predict functional status using a cut-off value less than 38.08%.

CONCLUSIONS

Right atrial deformation is significantly damaged in PH patients. Right atrial reservoir function can be estimated using 2D-STE, which gradually decreases in PH patients with different World Health Organization-functional class (WHO-FC). Right atrial PALS is a valuable factor for predicting the functional status and exercise capacity in PH patients.

Added clinical value of applying myocardial deformation imaging to assess right ventricular function

Right heart dysfunction has been found to be a strong prognostic factor predicting adverse outcome in various cardiopulmonary diseases. Conventional echocardiographic measurements can be limited by geometrical assumptions and impaired reproducibility. Speckle tracking-derived strain provides a robust quantification of right ventricular function. It explicitly evaluates myocardial deformation, as opposed to tissue Doppler-derived strain, which is computed from tissue velocity gradients. Right ventricular longitudinal strain provides a sensitive tool for detecting right ventricular dysfunction, even at subclinical levels. Moreover, the longitudinal strain can be applied for prognostic stratification of patients with pulmonary hypertension, pulmonary embolism, and congestive heart failure. Speckle tracking-derived right atrial strain, right ventricular longitudinal strain-derived mechanical dyssynchrony, and three-dimensional echocardiography-derived strain are emerging imaging parameters and methods. Their application in research is paving the way for their clinical use.

Right atrial strain is predictive of clinical outcomes and invasive hemodynamic data in group 1 pulmonary arterial hypertension

Transthoracic echocardiography (TTE) is a practical and widely used tool for risk stratification in pulmonary arterial hypertension (PAH). We hypothesized that right atrial (RA) reservoir function, represented by peak RA systolic strain, correlates with invasive hemodynamic measurements and clinical outcomes in PAH. Patients with group 1 PAH who had TTE within 6 months of index PAH clinic visit and right heart catheterization were included in this retrospective study. Peak RA strain in the 2D apical 4-chamber view was measured with speckle-tracking software. The primary endpoint was a composite of prostacyclin initiation, lung transplantation, and death. RA strain was also measured in healthy control subjects. Among the 37 patients studied, 25 (68%) met the primary endpoint. RA strain was significantly lower among patients who met the primary endpoint than among those who did not (mean 20% vs. 33%, P = 0.002). Strain was lower in PAH patients than in controls (mean 24% vs. 35%, P = 0.0001). RA strain correlated negatively with hemodynamic data including RA pressure (R = -0.31), mean pulmonary arterial pressure (R = -0.33), and pulmonary vascular resistance (R = -0.39), and positively with cardiac index (R = 0.44). In receiver operating characteristic analysis to distinguish between patients meeting the primary endpoint and event-free survivors, RA strain was not significantly different from RA volume, right ventricular (RV) fractional area change, RV basal diameter, or right ventricular systolic pressure (area under the curve 0.82, 0.81, 0.83, 0.86, and 0.97, respectively). Our results demonstrate that RA strain is predictive of clinical outcomes in PAH. Further research is needed to determine if RA strain is independently associated with outcomes in this population.

Right ventricular relative wall thickness as a predictor of outcomes and of right ventricular reverse remodeling for patients with pulmonary hypertension

Mid-term right ventricular (RV) reverse remodeling after treatment in patients with pulmonary hypertension (PH) is associated with long-term outcome as well as baseline RV remodeling. However, baseline factors influencing mid-term RV reverse remodeling after treatment and its prognostic capability remain unclear. We studied 54 PH patients. Mid-term RV remodeling was assessed in terms of the RV area, which was traced planimetrically at the end-systole (RVESA). RV reverse remodeling was defined as a relative decrease in the RVESA of at least 15% at 10.2 ± 9.4 months after treatment. Long-term follow-up was 5 years. Adverse events occurred in ten patients (19%) and mid-term RV reverse remodeling after treatment was observed in 37 (69%). Patients with mid-term RV reverse remodeling had more favorable long-term outcomes than those without (log-rank: p = 0.01). Multivariate logistic regression analysis showed that RV relative wall thickness (RV-RWT), as calculated as RV free-wall thickness/RV basal linear dimension at end-diastole, was an independent predictor of mid-term RV reverse remodeling (OR 1.334; 95% CI, 1.039-1.713; p = 0.03). Moreover, patients with RV-RWT ≥0.21 showed better long-term outcomes than did those without (log-rank p = 0.03), while those with RV-RWT ≥0.21 and mid-term RV reverse remodeling had the best long-term outcomes. Patients with RV-RWT <0.21 and without mid-term RV reverse remodeling, on the other hand, had worse long-term outcomes than other sub-groups. In conclusions, RV-RWT could predict mid-term RV reverse remodeling after treatment in PH patients, and was associated with long-term outcomes. Our finding may have clinical implications for better management of PH patients.