Reference right atrial dimensions and volume estimation by steady state free precession cardiovascular magnetic resonance

Right Ventricular Function in Takayasu's Arteritis Patients With Pulmonary Artery Involvement Using MRI Feature Tracking

BACKGROUND

Pulmonary artery involvement (PAI) is not rare in Takayasu arteritis (TA). Persistently elevated pulmonary arterial pressure in TA-PAI patients leads to pulmonary hypertension (PH), and eventually cardiac death. Thus, the early detection of right ventricular dysfunction before the onset of PH is important.

PURPOSE

To explore the potential of right ventricular global peak longitudinal and circumferential strain (RVGLS and RVGCS, respectively) in detecting right ventricular myocardial damage in TA-PAI patients without PH.

STUDY TYPE

Retrospective.

POPULATION

One hundred and six TA patients (39.6 ± 13.9 years), of whom 52 were non-PAI and 54 were PAI patients (36 without PH and 18 with PH), along with 58 sex- and age-matched healthy volunteers (HVs) (36.7 ± 13.2 years). The involved arteries were validated by aorta magnetic resonance (MR) angiography and pulmonary artery computed tomography angiography.

FIELD STRENGTH/SEQUENCE

3 T/Cine imaging sequence with a steady-state free precession readout.

ASSESSMENT

Cardiac MRI-derived parameters measured by two radiologists independently were compared among HVs, and TA patients with and without PAI. In addition, these indices were further compared among HVs, and TA-PAI patients with and without PH.

STATISTICAL TESTS

Student's t test, one-way ANOVA analysis, Pearson and Spearman correlation analysis, and reproducibility analysis. A P-value of <0.05 was considered statistically significant.

RESULTS

Although the TA-PAI patients without PH had a similar RV ejection fraction (RVEF) with HV (P = 0.348), RVGLS (non-PH 20.6 ± 3.7% vs. HV 24.0 ± 3.1%) was significantly lower and RVGCS (non-PH 14.8 ± 3.9% vs. HV 13.0 ± 2.7%) higher. The TA-PAI patients with PH had significantly poorer RVGLS (PH 13.5 ± 3.8% vs. non-PH 20.6 ± 3.7%) and RVGCS (PH 10.9 ± 3.2% vs. non-PH 14.8 ± 3.9%) than those without PH.

DATA CONCLUSION

Right ventricular dysfunction was detected in the TA-PAI patients without PH. MR-feature tracking may be an effective method for detecting early cardiac damage in the TA-PAI patients without PH.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 3.

Assessment of Tricuspid Regurgitation by Cardiac Magnetic Resonance Imaging: Current Role and Future Applications

Tricuspid regurgitation (TR) is a prevalent valvular disease with a significant mortality rate. The evaluation of TR severity and associated right heart remodeling and dysfunction is crucial to determine the optimal therapeutic strategy and to improve prognosis. While echocardiography remains the first-line imaging technique to evaluate TR, it has many limitations, both operator- and patient-related. Cardiovascular magnetic resonance imaging (CMR) has emerged as an innovative and comprehensive non-invasive cardiac imaging technique with additional value beyond routine echocardiographic assessment. Besides its established role as the gold standard for the evaluation of cardiac volumes, CMR can add important insights with regard to valvular anatomy and function. Accurate quantification of TR severity, including calculation of regurgitant volume and fraction, can be performed using either the well-known indirect volumetric method or novel 4D flow imaging. In addition, CMR can be used to assess the impact on the right heart, including right heart remodeling, function and tissue characterization. Several CMR-derived parameters have been associated with outcome, highlighting the importance of multi-modality imaging in patients with TR. The aim of this review is to provide an overview of the current role of CMR in the assessment and management of patients with TR and its future applications.

Atrial dimension reference values in healthy participants using the biplane/monoplane method for clinical and research use

AIM

To provide reference values of the dimensions of the left and right atrium (RA) obtained using the biplane and monoplane methods, respectively, on two- and four-chamber views, which represent the standard projections acquired in clinical practice, and correlation with body surface area (BSA), age, and gender.

MATERIALS AND METHODS

Healthy volunteers, M:F = 1:1, including five participants per gender and age decile from 20 to 70 years, who underwent cardiovascular magnetic resonance imaging (CMR) were enrolled prospectively. Normal atrial reference values were calculated for male and female subpopulations and stratified by age. Atrial areas and volumes were assessed both as absolute values and indexed to BSA. Differences among genders and correlation with age were assessed. Intra- and interobserver reproducibility were assessed in a subpopulation.

RESULTS

Fifty participants (mean age 43.3 ± 14 years, 25 men) were evaluated. Image analysis took <1 minute for each subject (mean time 30 ± 5 seconds). Intra- and interobserver reproducibility were excellent (ICC >0.85 for all datasets). RA areas were significantly higher in males (p=0.0001). The left atrial (LA) surface did not show significant differences among genders. Atrial areas normalised to BSA did not show significant gender differences. Both right and left absolute atrial volumes turned out to be significantly higher in males (p=0.0001 and p=0.0047, respectively), and normalised to BSA remained significantly different only for the RA (p=0.0006). Neither atrial volume nor areas showed significant correlation with age.

CONCLUSIONS

The monoplane method is a fast and reproducible technique to assess atrial dimensions. Absolute atrial dimensions show significant variations among genders. Gender-specific reference ranges for atrial dimensions are recommended.

Electroanatomical Conduction Characteristics of Pig Myocardial Tissue Derived from High-Density Mapping

BACKGROUND

Ultra-high-density mapping systems allow more precise measurement of the heart chambers at corresponding conduction velocities (CVs) and voltage amplitudes (VAs). Our aim for this study was to define and compare a basic value set for unipolar CV and VA in all four heart chambers and their separate walls in healthy, juvenile porcine hearts using ultra-high-density mapping.

METHODS

We used the Rhythmia Mapping System to create electroanatomical maps of four pig hearts in sinus rhythm. CVs and VAs were calculated for chambers and wall segments with overlapping circular areas (radius of 5 mm).

RESULTS

We analysed 21 maps with a resolution of 1.4 points/mm2. CVs were highest in the left atrium (LA), followed by the left ventricle (LV), right ventricle (RV), and right atrium (RA). As for VA, LV was highest, followed by RV, LA, and RA. The left chambers had a higher overall CV and VA than the right. Within the chambers, CV varied more in the right than in the left chambers, and VA varied in the ventricles but not in the atria. There was a slightly positive correlation between CVs and VAs at velocity values of <1.5 m/s.

CONCLUSIONS

In healthy porcine hearts, the left chambers showed higher VAs and CVs than the right. CV differs mainly within the right chambers and VA differs only within the ventricles. A slightly positive linear correlation was found between slow CVs and low VAs.

Cardiac reverse remodeling in primary mitral regurgitation: mitral valve replacement vs. mitral valve repair

BACKGROUND

When feasible, guidelines recommend mitral valve repair (MVr) over mitral valve replacement (MVR) to treat primary mitral regurgitation (MR), based upon historic outcome studies and transthoracic echocardiography (TTE) reverse remodeling studies. Cardiovascular magnetic resonance (CMR) offers reference standard biventricular assessment with superior MR quantification compared to TTE. Using serial CMR in primary MR patients, we aimed to investigate cardiac reverse remodeling and residual MR post-MVr vs MVR with chordal preservation.

METHODS

83 patients with ≥ moderate-severe MR on TTE were prospectively recruited. 6-min walk tests (6MWT) and CMR imaging including cine imaging, aortic/pulmonary through-plane phase contrast imaging, T1 maps and late-gadolinium-enhanced (LGE) imaging were performed at baseline and 6 months after mitral surgery or watchful waiting (control group).

RESULTS

72 patients completed follow-up (Controls = 20, MVr = 30 and MVR = 22). Surgical groups demonstrated comparable baseline cardiac indices and co-morbidities. At 6-months, MVr and MVR groups demonstrated comparable improvements in 6MWT distances (+ 57 ± 54 m vs + 64 ± 76 m respectively, p = 1), reduced indexed left ventricular end-diastolic volumes (LVEDVi; - 29 ± 21 ml/m2 vs - 37 ± 22 ml/m2 respectively, p = 0.584) and left atrial volumes (- 23 ± 30 ml/m2 and - 39 ± 26 ml/m2 respectively, p = 0.545). At 6-months, compared with controls, right ventricular ejection fraction was poorer post-MVr (47 ± 6.1% vs 53 ± 8.0% respectively, p = 0.01) compared to post-MVR (50 ± 5.7% vs 53 ± 8.0% respectively, p = 0.698). MVR resulted in lower residual MR-regurgitant fraction (RF) than MVr (12 ± 8.0% vs 21 ± 11% respectively, p = 0.022). Baseline and follow-up indices of diffuse and focal myocardial fibrosis (Native T1 relaxation times, extra-cellular volume and quantified LGE respectively) were comparable between groups. Stepwise multiple linear regression of indexed variables in the surgical groups demonstrated baseline indexed mitral regurgitant volume as the sole multivariate predictor of left ventricular (LV) end-diastolic reverse remodelling, baseline LVEDVi as the most significant independent multivariate predictor of follow-up LVEDVi, baseline indexed LV end-systolic volume as the sole multivariate predictor of follow-up LV ejection fraction and undergoing MVR (vs MVr) as the most significant (p < 0.001) baseline multivariate predictor of lower residual MR.

CONCLUSION

In primary MR, MVR with chordal preservation may offer comparable cardiac reverse remodeling and functional benefits at 6-months when compared to MVr. Larger, multicenter CMR studies are required, which if the findings are confirmed could impact future surgical practice.

Description of a new clinical syndrome: thoracic constriction without evidence of the typical funnel-shaped depression-the "invisible" pectus excavatum

Pectus excavatum (PE) is a congenital malformation with a funnel-shaped depression of the sternum that can lead to cardiac symptoms. However, there are patients with thoracic constriction (defined as elevated Haller-Index > 3.25 determined by cardiac magnetic resonance imaging (CMR)) without visible evidence of PE, leading to similar complaints. Between January 2004 till June 2020, patients who underwent CMR for further evaluation of the heart, due to cardiac symptoms were enrolled and compared to controls. Biventricular global strain analysis was assessed using feature tracking (CMR-FT). ECG and/or Holter recordings were performed to detect rhythm events. Cardiac symptoms were evaluated in detail using a questionnaire. Finally, 88 patients (male 35, female 53) with elevated Haller-Index (3.9 ± 0.8) were included and compared to CMR data from 25 individuals with confirmed PE and 25 healthy controls (HC). Mean age at time of CMR was 35 ± 16 years. The most common symptoms at presentation were palpitations (41%), followed by dyspnea (24%) and atypical chest pain (14%). Three patients (3%) had atrial fibrillation or atrial flutter. Concomitant phenomena were pericardial effusion in 39% and mitral valve prolapse (MVP) in 27% of the study cohort. While there were no differences in left ventricular function or volumes, right ventricular function (RVEF) was significantly lower in patients with internal PE compared to HC (RVEF (%) 50 ± 5 vs 59 ± 4, p < 0.01). Strain analysis revealed only discrete changes in RV strain, implying a purely mechanical problem in the absence of structural changes. RV dimensions were negatively correlated with the size of thoracic indices (r = 0.41), reflecting the extent of thoracic constriction. MVP was more prevalent in patients with greater thoracic indices (r = 0.24). The described cohort, referred to as internal PE because of the absence of external changes, showed similar CMR morphologic findings as patients with real PE (especially altered dimensions of the right heart and a lower RVEF). In addition, there was a high incidence of rhythm disturbances, such as extrasystoles or arrhythmias. In one-third of the study cohort additional abnormalities such as pericardial effusion or MVP were present, with MVP being found more frequently in patients with larger thoracic indices, suggesting a possible common pathogenesis.Trial registration: ISRCTN registry, ISRCTN15355937, retrospectively registered 03.06.2022, https://www.isrctn.com/ISRCTN15355937?q=15355937&filters=&sort=&offset=1&totalResults=1&page=1&pageSize=10 .

Risk factors for atrial arrhythmia recurrence after atrial arrhythmia surgery with pulmonary valve replacement

Objectives

Atrial arrhythmias are a significant cause of late morbidity and mortality in patients after tetralogy of Fallot repair. However, reports on their recurrence following atrial arrhythmia surgery are limited. We aimed to identify the risk factors for atrial arrhythmia recurrence after pulmonary valve replacement (PVR) and arrhythmia surgery.

Methods

We reviewed 74 patients with repaired tetralogy of Fallot who underwent PVR for pulmonary insufficiency at our hospital between 2003 and 2021. Twenty-two patients (mean age, 39 years) underwent PVR and atrial arrhythmia surgery. A modified Cox-maze III was performed in 6 patients with chronic atrial fibrillation, and a right-sided maze was performed in 12 with paroxysmal atrial fibrillation, 3 with atrial flutter, and 1 with atrial tachycardia. Atrial arrhythmia recurrence was defined as any documented sustained atrial tachyarrhythmia requiring intervention. The influence of preoperative parameters on recurrence was assessed with the Cox proportional-hazards model.

Results

The median follow-up period was 9.2 years (interquartile range, 4.5-12.4). Cardiac death and redo-PVR due to prosthetic valve dysfunction were not observed. Eleven patients had atrial arrhythmia recurrence after discharge. Atrial arrhythmia recurrence-free rates were 68% at 5 years and 51% at 10 years after PVR and arrhythmia surgery. Multivariable analysis revealed that right atrial volume index (hazard ratio, 1.04; 95% confidence interval, 1.01-1.08, P = .009) was a significant risk factor for atrial arrhythmia recurrence after arrhythmia surgery and PVR.

Conclusions

Preoperative right atrial volume index was associated with atrial arrhythmia recurrence, which may assist in planning the timing of atrial arrhythmia surgery and PVR.

Risk Stratification and Outcomes in Patients With Pulmonary Hypertension: Insights into Right Ventricular Strain by MRI Feature tracking

BACKGROUND

Despite a recommended multidimensional approach for pulmonary hypertension (PH) risk stratification and guidance of treatment decisions, this may not always be achievable in patients with advanced disease. One issue is the lack of an imaging modality to assess right ventricular (RV) structure and function abnormalities.

PURPOSE

To explore the risk stratification and prognostic value of cardiac MR feature tracking (MR-FT)-derived RV strain.

STUDY TYPE

Retrospective.

POPULATION

A total of 80 patients with idiopathic pulmonary artery hypertension (N = 52) or chronic thromboembolic PH (N = 28).

FIELD STRENGTH

A 1.5 T or 3.0 T, balanced steady-state free precession sequence.

ASSESSMENT

All patients underwent laboratory testing, right heart catheterization, and MR imaging (and in 37 cases, a cardiopulmonary exercise test was also performed) within a 1-month period. Cardiac functional parameters and both global longitudinal strain (GLS) and global circumferential strain (GCS) were analyzed. Patients were stratified into low, intermediate, and high-risk groups by guideline suggested stratified values of risk factors. The combined endpoint was death or hospitalization for congestive heart failure assessed during follow-up since the date of MR examination.

STATISTICAL TESTS

Kolmogorov-Smirnov's test, independent-sample t-tests, Wilcoxon's rank-sum tests, one-way analysis of variance, χ² tests or Fisher's exact test, receiver operating characteristic analysis, Kaplan-Meier survival analysis, and Cox regression analysis. A P value < 0.05 was considered statistically significant.

RESULTS

The median follow-up duration was 3.4 years. Thirty-five patients presented with combined endpoint including 10 cardiac deaths. RV structural and deformation impairments were significantly associated with combined endpoint (ejection fraction: 31.3% ± 13.2% vs. 38.0% ± 14.8%, hazard ratio [HR: 0.974; GLS: -14.5 [-18.6, -10.9] % vs. -20.4 [-26.0, -13.2] %, HR: 1.071; GCS: -9.8 [-14.5, -7.3] % vs. -12.3 [-19.9, -8.4] %, HR: 1.059). There were significant differences in RVGLS among low, intermediate, and high-risk groups (-19.3% ± 7.2% vs. -17.3% ± 9.4% vs. -11.5% ± 4.4% by cardiac functional class, -21.8% ± 7.3% vs. -19.4% ± 8.2% vs. -12.7 ± 5.3% by NT-proBNP, -19.7% ± 7.7 vs. -15.8% ± 6.5% vs. -12.6% ± 8.2% by cardiac index).

DATA CONCLUSION

RV deformation may aid risk stratification in patients with PH, providing crucial information for RV remodeling, pulmonary hemodynamic condition and exercise capacity.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Prevalence and determinants of tricuspid regurgitation after repair of tetralogy of Fallot

BACKGROUND

The prevalence and determinants of tricuspid regurgitation (TR) in patients with repaired Tetralogy of Fallot (rTOF) remain incompletely understood.

OBJECTIVES

To explore the prevalence of and factors associated with TR in patients with rTOF, specifically, the relationship of right ventricular (RV) dilatation with TR severity.

METHODS

Patients (≥17 yrs) with rTOF referred to our service (2000-2019) were identified. Those with severe pulmonary stenosis, significant shunt, or previous tricuspid valve surgery were excluded. Using standard cardiac MRI protocols, RV, right atrial (RA) and tricuspid valve (TV) parameters were measured and compared.

RESULTS

68 consecutively eligible patients with rTOF were included in the study (27 ± 9 yrs., 35% female). Despite substantial RV volume overload (mean RVEDVi 153 mL/m²), the majority of the cohort (78%) had no or only mild TR. RA volumes, tenting height/area and annular diameter were normal (4.9 ± 2.0 mm, 1.1 ± 1.0 cm² and 32.4 ± 6.2 mm, respectively). There was no significant correlation of TR fraction with RVEDVi (r = 0.13; p = 0.30), RVEF (r = 0.09; p = 0.44) or tricuspid annular diameter (r = 0.07; p = 0.62). Only RAVi showed a weak but significant correlation with TR fraction (0.29; p = 0.03). In a pooled cohort analysis, including both rTOF patients and adults with a dilated RV from pre-tricuspid shunt lesions, only rTOF was independently associated with higher TR fraction (p = 0.017).

CONCLUSION

Despite substantial RV dilatation in a cohort with rTOF, there was surprisingly little TR. We found poor correlation between RVEDVi, RA volumes, tricuspid annular dilatation and the presence of significant TR. These findings question commonly held notions regarding the pathophysiology of functional TR in these patients.

Average values for real-time two and three-dimensional echocardiographic parameters of mitral and tricuspid valves in a healthy Iranian population

BACKGROUND

The reliability and validity of echocardiography are critical issues. Day and age, defining normal cases necessitates expressing natural physiological differences, including ethnicity.

OBJECTIVE

We are persuaded to evaluate average values in mitral and tricuspid valves in the Iranian population because only a few studies have been conducted to obtain average measures in echocardiography.

METHOD

This six-month study was conducted in a tertiary center's echocardiography lab. This study included 87 healthy Iranian volunteers who had no health issues. The tricuspid and mitral valves were examined using three and two-dimensional echocardiography. The investigated indicators produced normal data. The cases were divided into six age groups with a 12-year age gap.

RESULTS

The participants ranged in age from 18 to 90, with 35 males (40/2 %) and 52 females (59/8%). By comparing tricuspid and mitral valve indices, this study found a difference between men and women (P<0.05). Furthermore, a difference in MV3D1, MV2CH1, MVPLAX1, MV3D2, MV4CH1, MV2CH1, MV ALAX2, MV2CH2, MV TENTING AREA, MV AREA indices at the mitral valve, and SAX2 TV4CH1, TV4CH2, TVSAX1, TVRVIF2 indices at the tricuspid valve was observed in various age groups (P-value<0.05).

CONCLUSIONS

Our findings confirmed that gender and age impacted echocardiographic parameters, with a trend of decreasing measurements after 65 years of age and the most significant dimensions obtained after 42 years of age.

Left atrial strain correlates with severity of cardiac involvement in Anderson-Fabry disease

OBJECTIVES

Cardiac involvement in Anderson-Fabry disease (AFD) results in myocardial lipid depositions. An early diagnosis can maximize therapeutic benefit. Thus, this study aims to investigate the potential of cardiac MRI (CMR) based parameters of left atrial (LA) function and strain to detect early stages of AFD.

METHODS

Patients (n = 58, age 40 (29-51) years, 31 female) with genetically proven AFD had undergone CMR including left ventricular (LV) volumetry, mass index (LVMi), T1, and late gadolinium enhancement, complemented by LA and LV strain measurements and atrial emptying fractions. Patients were stratified into three disease phases and compared to age and sex-matched healthy controls (HC, n = 58, age 41 [26-56] years, 31 female).

RESULTS

A total of 19 early-, 20 intermediate-, and 19 advanced-phase patients were included. LV and LA reservoir strain was significantly impaired in all AFD phases, including early disease (both p < 0.001). In contrast, LA volumetry, T1, and LVMi showed no significant differences between the early phase and HC (p > 0.05). In the intermediate phase, LVMi and T1 demonstrated significant differences. In advanced phase, all parameters except active emptying fractions differed significantly from HC. ROC curve analyses of early disease phases revealed superior diagnostic confidence for the LA reservoir strain (AUC 0.88, sensitivity 89%, specificity 75%) over the LV strain (AUC 0.82).

CONCLUSIONS

LA reservoir strain showed impairment in early AFD and significantly correlated with disease severity. The novel approach performed better in identifying early disease than the established approach using LVMi and T1. Further studies are needed to evaluate whether these results justify earlier initiation of therapy and help minimize cardiac complications.

KEY POINTS

• Parameters of left atrial function and deformation showed impairments in the early stages of Anderson-Fabry disease and correlated significantly with the severity of Anderson-Fabry disease. • Left atrial reservoir strain performed superior to ventricular strain in detecting early myocardial involvement in Anderson-Fabry disease and improved diagnostic accuracies of approaches already using ventricular strain. • Further studies are needed to evaluate whether earlier initiation of enzyme replacement therapy based on these results can help minimize cardiac complications from Anderson-Fabry disease.

Left Atrial Dysfunction in Children with Repaired Pulmonary Artery Atresia with Ventricular Septal Defect: A Cardiovascular Magnetic Resonance Imaging Study

(1) Background: The left atrium (LA) is much more than a reservoir for left ventricular filling. The aim of this study was to assess the LA volume and function in patients with repaired pulmonary artery atresia with ventricular septal defect (rPA/VSD) using CMR. (2) Methods: 31 pediatric patients with rPA/VSD and 30 healthy controls were prospectively recruited. Left atrial ejection fraction (EF), strain and strain rate of three phases (reservoir, conduit, and pump) and left atrial volume were measured with cardiac function analysis software. (3) Results: Patients with rPA/VSD had decreased maximal volume index (p = 0.008). Compared to controls, LA reservoir strain and strain rate, conduit strain and strain rate, booster pump strain rate, total EF and passive EF were significantly lower (p = 0.001, p < 0.001, p = 0.001, p = 0.02, p = 0.03, p < 0.001, p < 0.001); the patients with preserved but lower RVEF(<50%) had lower reservoir strain, reservoir strain rate and pump strain rate (p = 0.01, p = 0.02, p = 0.04, respectively) than the patients with higher RVEF (≥50%). (4) Conclusions: In patients with rPA/VSD, LA function was altered when biventricular EF was preserved, which may provide an early indication of left ventricular diastolic dysfunction. CMR can detect LA dysfunction at an early stage, even before LA enlargement.

Cardiac Radiofrequency Ablation Simulation Using a 3D-Printed Bi-Atrial Thermochromic Model

Radiofrequency ablation (RFA) is a treatment used in the management of various arrhythmias including atrial fibrillation. Enhanced training for electrophysiologists through the use of physical simulators has a significant role in improving patient outcomes. The requirements for a high-fidelity simulator for cardiac RFA are challenging and not fully met by any research or commercial simulator at present. In this study, we have produced and evaluated a 3D-printed, bi-atrial model contained in a custom-made enclosure for RFA simulation using a new soft tissue-mimicking polymer, Layfomm-40, combined with thermochromic pigment and barium sulphate in an acrylic paint carrier. We evaluated the conductive properties of Layfomm-40, its sensitivity to RFA, and its visibility in X-ray imaging, and carried a full simulation of RFA in the cardiac catheterization laboratory by an electrophysiologist. We demonstrated that a patient-specific 3D-printed Layfomm-40 bi-atrial model coated with a custom thermochromic/barium sulphate paint was compatible with the CARTO3 electroanatomic mapping system and could be effectively imaged using X-ray fluoroscopy. We demonstrated the effective delivery and visualization of radiofrequency ablation lesions in this model. The simulator meets nearly all the requirements for high-fidelity physical simulation of RFA. The use of such simulators is likely to have impact on the training of electrophysiologists and the evaluation of novel RFA devices.

Imaging assessment of the right atrium: anatomy and function

The right atrium (RA) is the cardiac chamber that has been least well studied. Due to recent advances in interventional cardiology, the need for greater understanding of the RA anatomy and physiology has garnered significant attention. In this article, we review how a comprehensive assessment of RA dimensions and function using either echocardiography, cardiac computed tomography, and magnetic resonance imaging may be used as a first step towards a better understanding of RA pathophysiology. The recently published normative data on RA size and function will likely shed light on RA atrial remodelling in atrial fibrillation (AF), which is a complex phenomenon that occurs in both atria but has only been studied in depth in the left atrium. Changes in RA structure and function have prognostic implications in pulmonary hypertension (PH), where the increased right ventricular (RV) afterload first induces RV remodelling, predominantly characterized by hypertrophy. As PH progresses, RV dysfunction and dilatation may begin and eventually lead to RV failure. Thereafter, RV overload and increased RV stiffness may lead to a proportional increase in RA pressure. This manuscript provides an in-depth review of RA anatomy, function, and haemodynamics with particular emphasis on the changes in structure and function that occur in AF, tricuspid regurgitation, and PH.

A Variable-Volume Heart Model for Galvanic Coupling-Based Conductive Intracardiac Communication

Conductive intracardiac communication (CIC) has become one of the most promising technologies in multisite leadless pacemakers for cardiac resynchronization therapy. Existing studies have shown that cardiac pulsation has a significant impact on the attenuation of intracardiac communication channels. In this study, a novel variable-volume circuit-coupled electrical field heart model, which contains blood and myocardium, is proposed to verify the phenomenon. The influence of measurements was combined with the model as the equivalent circuit. Dynamic intracardiac channel characteristics were obtained by simulating models with varying volumes of the four chambers according to the actual cardiac cycle. Subsequently, in vitro experiments were carried out to verify the model's correctness. Among the dependences of intracardiac communication channels, the distance between pacemakers exerted the most substantial influence on attenuation. In the simulation and measurement, the relationship between channel attenuation and pulsation was found through the variable-volume heart model and a porcine heart. The CIC channel attenuation had a variation of less than 3 dB.

Sex Matters: A Comprehensive Comparison of Female and Male Hearts

Cardiovascular disease in women remains under-diagnosed and under-treated. Recent studies suggest that this is caused, at least in part, by the lack of sex-specific diagnostic criteria. While it is widely recognized that the female heart is smaller than the male heart, it has long been ignored that it also has a different microstructural architecture. This has severe implications on a multitude of cardiac parameters. Here, we systematically review and compare geometric, functional, and structural parameters of female and male hearts, both in the healthy population and in athletes. Our study finds that, compared to the male heart, the female heart has a larger ejection fraction and beats at a faster rate but generates a smaller cardiac output. It has a lower blood pressure but produces universally larger contractile strains. Critically, allometric scaling, e.g., by lean body mass, reduces but does not completely eliminate the sex differences between female and male hearts. Our results suggest that the sex differences in cardiac form and function are too complex to be ignored: the female heart is not just a small version of the male heart. When using similar diagnostic criteria for female and male hearts, cardiac disease in women is frequently overlooked by routine exams, and it is diagnosed later and with more severe symptoms than in men. Clearly, there is an urgent need to better understand the female heart and design sex-specific diagnostic criteria that will allow us to diagnose cardiac disease in women equally as early, robustly, and reliably as in men.

Systematic Review Registration

https://livingmatter.stanford.edu/.

Right ventricular volume and its relationship to functional tricuspid regurgitation

Background

Significant right ventricular (RV) dilatation has long been considered integral to the pathogenesis of functional tricuspid regurgitation (FTR).

Objectives

To explore the relationship of RV dilatation and FTR in patients with ‘pure’ RV volume overload.

Methods

Patients (>17yrs) with RV dilatation due to pre-tricuspid shunts (atrial septal defect; ASD and/or partial anomalous pulmonary venous drainage; PAPVD) referred to our service (2000–2019) were retrospectively identified. Those with pulmonary hypertension, primum ASD or left-heart disease were excluded. Using standard cardiac MRI protocols, RV, right atrial and TV parameters were measured and compared.

Results

Of 52 consecutively eligible patients (42 ± 15yrs, 25 males), 25 had ASDs, 13 had PAPVD and 14 had both conditions. All were in sinus rhythm and none had pulmonary regurgitation. Left and right ventricular ejection fractions were normal (LVEF 63 ± 8%, RVEF 56 ± 8%). Indexed RV end-diastolic volumes (RVEDVi) were moderately increased (males 148 ± 33 mL/m² and females 141 ± 42 mL/m², range 95–267 mL/m²). Despite substantial RV volume overload, no patients had severe tricuspid regurgitation (TR). Only two had > mild TR. There was a weak correlation between tricuspid annular diameter and both degree of RV dilatation (r = 0.37; p = 0.01) and degree of TR (r = 0.38; p = 0.006). There was a similarly poor correlation between right atrial dimensions and the degree of TR (r = 0.34; p = 0.02).

Conclusion

When RV dilatation is simply due to volume overload, we find that significant TR is extremely rare. This gives an important and novel insight; that RV dilatation per se does not result in FTR.

Right Heart Morphology of Candidate Patients for Transcatheter Tricuspid Valve Interventions

Purpose

This study quantitatively evaluated the phasic right heart morphology of candidate patients for a transcatheter tricuspid valve intervention (N=32) and of subjects with trace to no tricuspid regurgitation (N = 14).

Methods

Cardiac computed tomography angiography (CCTA) and transthoracic/transesophageal echocardiography (TTE/TEE) images were analyzed using dedicated research and clinical software. Using CCTA, the phasic right atrial and ventricular volumes, annulus dimensions, annulus-to-right coronary artery (RCA) distances, circumferential topography of the annular tissue shelf, vena cava dimensions (inferior and superior), vena cava positions, axis angles, and annular excursions were quantified. Using TTE/TEE, leaflet geometry, regurgitation, hemodynamics, and heart function were quantified. Measurements within and between groups were quantitatively compared with regression analyses to explore relationships between right heart features.

Results

The phasic position and orientation of the vena cava and the circumferential topography of the annular tissue shelf were quantitatively presented for the first time. The candidate patient group exhibited greater chamber dimensions, enlarged vena cava, distended vena cava positions, positional shallowing of the annular tissue shelf, geometric annular distortion, leaflet distention, moderate or greater regurgitation, and impaired ventricular function. Atrial volume correlated strongly with directional vena cava positions as well as with annular dimensions. Annulus-to-RCA distances and annular excursions were comparable between groups.

Conclusions

This study provides new and further insight to the right heart morphology and functional characteristics of candidate patients for a transcatheter tricuspid valve intervention. These data provide a platform from which these patients can continue to be better understood for further improving transcatheter system design and use.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13239-021-00595-y.

Assessment of the tricuspid valve using cardiovascular magnetic resonance

PURPOSE OF REVIEW

The rapid search for suitable tricuspid transcatheter devices has ignited renewed enthusiasm in accurate characterization of tricuspid valve disease. Cardiovascular magnetic resonance (CMR), traditionally used as the gold standard in assessment for right ventricular size and function, has recently seen its use expanded to assess both the structure and function of the tricuspid apparatus. This review will highlight the role of CMR in tricuspid valve disease and compare it with other commonly used imaging modalities.

RECENT FINDINGS

Dynamic anatomical assessment of the tricuspid apparatus, in combination with accurate leaflet identification, is possible with CMR. Tricuspid regurgitation volume and fraction are derived through an indirect volumetric method, and therefore, able to overcome many traditional hurdles involved with valve regurgitation quantitation. Adverse right heart prognostic factors in tricuspid valve disease, such as right heart volumes, function, and tissue characterization, are optimally assessed using CMR.

SUMMARY

Cardiovascular magnetic resonance is a powerful modality that should be harnessed in order to obtain a multifaceted assessment of tricuspid valve structure, function, and the effects of valve disease on right heart remodeling.

European Association of Cardiovascular Imaging expert consensus paper: a comprehensive review of cardiovascular magnetic resonance normal values of cardiac chamber size and aortic root in adults and recommendations for grading severity

This consensus paper provides a framework for grading of severity of cardiovascular magnetic resonance (CMR) imaging-based assessment of chamber size, function, and aortic measurements. This does not currently exist for CMR measures. Differences exist in the normal reference values between echocardiography and CMR along with differences in methods used to derive these. We feel that this document will significantly complement the current literature and provide a practical guide for clinicians in daily reporting and interpretation of CMR scans. This manuscript aims to complement a recent comprehensive review of CMR normal value publications to recommend cut-off values required for severity grading. Standardization of severity grading for clinically useful CMR parameters is encouraged to lead to clearer and easier communication with referring clinicians and may contribute to better patient care. To this end, the European Association of Cardiovascular Imaging (EACVI) has formed this expert panel that has critically reviewed the literature and has come to a consensus on approaches to severity grading for commonly quantified CMR parameters.

Comparison of the early cardiac electromechanical remodeling following transcatheter and surgical secundum atrial septal defect closure in adults

Background

Secundum atrial septal defect (ASD) closure leads to electrical and mechanical remodeling that occurs early after shunt disappearance. The relationship between electromechanical remodeling using electrocardiogram (ECG) and cardiac magnetic resonance (CMR) after percutaneous and surgical closure has not yet been recorded in prospective studies.

Objective

We thought to study right atrium (RA) and right ventricle (RV) changes by CMR 3 months after transcatheter and surgical closure and their comparison with electrical remodeling by ECG.

Results

We prospectively evaluated 30 consecutive adult patients with isolated secundum ASD who were referred for (transcatheter and surgical) ASD closure.

There was significant reduction in all of the electrical parameters within the same group as compared to the baseline values, except P wave dispersion (Pd). (P max was 97.33 ± 16.67 (pre closure) to 76 ± 15.49 (post closure) in the device group and 97.33 ± 12.79 (preclosure) to 73.33 ± 16.32 (post closure) in the surgical group, QRS complex was 104 ± 18.82 (preclosure) to 80 ± 18.51 (post closure) in the device group and 106.67 ± 14.47 (preclosure) to 86.67 ± 17.99 (post closure) in the surgical group. QTc maximum was 478.53 ± 36.79 (preclosure) to 412.53 ± 38.03 (post closure) in the device group and 470.53 ± 65.70 (preclosure) to 405.93 ± 63.08 (post closure) in the surgical group, and QTc dispersion was 70.33 ± 24.04 (preclosure) to 60.26 ± 28.56 (post closure) in the device group and 80.73 ± 30.38 (preclosure) to 60.27 ± 28.57 (post closure) in the surgical group).There was no significant difference between two groups indicating that transcatheter and surgical closure had led to equivalent value of electrical remodeling.

In CMR study, we measured RA maximal volume and right ventricle end diastolic volume (RVEDV), RA maximal volume decreased significantly as compared to the base line values post closure in both groups (P value < 0.001). The reduction in RA max volume was more in the transcatheter closure group; however, this difference was not statistically significant when compared with the surgical arm (P value = 0.5).RVEDV decreased significantly in both groups as compared to the baseline values (P value < 0.001). Transcatheter closure resulted in more significant reduction in the RVEDV than the surgical closure (P value = 0.03).

Conclusion

Our study showed early significant electromechanical reverse remodeling in most of the study parameters from the baseline values after ASD closure. We found no significant differences in all of the electrical and RA mechanical remodeling parameters with significantly better mechanical remodeling of RV in the device group.

Age- and Sex-Specific Changes in CMR Feature Tracking-Based Right Atrial and Ventricular Functional Parameters in Healthy Asians

Cardiovascular magnetic resonance (CMR) is the reference standard for non-invasive assessment of right-sided heart function. Recent advances in CMR post-processing facilitate quantification of tricuspid annular (TA) dynamics and longitudinal strains of the right ventricle (RV) and right atrium (RA). We aimed to determine age- and sex-specific changes in CMR-derived TA dynamics, and RV and RA functional parameters in healthy Asian adults. We studied 360 healthy subjects aged 21-79 years, with 30 men and 30 women in each of the six age groups. Functional parameters of RV and RA were measured on standard four-chamber cine CMR using fast feature tracking: (1) TA peak velocities (systolic velocity S', early diastolic velocity E', late diastolic velocity A') and TA plane systolic excursion (TAPSE); (2) RV global longitudinal strain (GLS) and strain rates; and (3) RA phasic longitudinal strains and strain rates. S' and TAPSE exhibited negative correlations with age. RV GLS was significantly higher in females than in males but not associated with age in both sexes. Females had similar E', lower A', and higher E'/A' ratios compared to males. Positive associations of E' and E'/A', and negative association of A' with age were observed in both sexes. Females had higher RA reservoir and conduit strains compared to males. There were significantly negative and positive associations between RA conduit and booster strains, respectively, with age. Age- and sex-specific reference ranges were established, and associations revealed, for fast CMR feature tracking parameters of right heart function in a large normal Asian population.

Right atrium and cryptogenic ischaemic stroke in the young: a case-control study

Background

Recent studies suggest left atrial (LA) dysfunction in cryptogenic stroke. We studied the dynamics of right atrium (RA) and right atrial appendage (RAA) in young adults with cryptogenic stroke. We hypothesised that bi-atrial dysfunction and blood stagnation might contribute to thrombosis formation in patients with patent foramen ovale (PFO), as deep venous thrombosis is detected only in the minority of patients.

Methods

Thirty patients (aged 18–49) with a first-ever cryptogenic stroke and 30 age-matched and sex-matched stroke-free controls underwent cardiac magnetic resonance (CMR) imaging. An approach to estimate the RAA volume was developed, using crista terminalis and pectinate muscles as anatomical landmarks. Atrial expansion indices were calculated as (maximal volume – minimal volume) ×100%/minimal volume. Total pulmonary to systemic blood flow ratio (Qp/Qs) was based on phase contrast CMR. Right-to-left shunt (RLS) was evaluated with transoesophageal echocardiography in 29 patients and transcranial Doppler in 30 controls, moderate-to-severe RLS considered as clinically significant.

Results

We found that RA and RAA volumes were similar between patients and controls. Also, RA expansion index was similar, but RAA (95.6%±21.6% vs 108.7%±25.8%, p=0.026) and LA (126.2%±28% vs 144.9%±36.3%, p=0.023) expansion indices were lower in patients compared with controls. Seven (24%) of 29 patients had an RLS compared with 1 (3%) of 30 controls (p=0.012). Among 59 study subjects, RLS was associated with lower RA (81.9%±15.9% vs 98.5%±29.5%, p=0.030), RAA (84.7%±18% vs 105.6%±24.1%, p=0.022), LA (109.8%±18.6% vs 140.1%±33.7%, p=0.017) and LAA (median 102.9% (IQR 65.6%–121.7%) vs 229.1% (151.8%–337.5%], p=0.002) expansion indices and lower Qp/Qs ratio (0.91±0.06 vs 0.98±0.07, p=0.027).

Conclusions

This study suggests bi-atrial dysfunction in young adults with cryptogenic stroke, associated with moderate-to-severe RLS. Dysfunction of the atria and atrial appendages may be an additional mechanism for PFO-related stroke.

Trial registration number

NCT01934725.

CMR feature tracking strain patterns and their association with circulating cardiac biomarkers in patients with hypertrophic cardiomyopathy

Aims

CMR feature tracking strain (CMR-FT) provides prognostic information. However, there is a paucity of data in hypertrophic cardiomyopathy (HCM). We sought to analyze global CMR-FT parameters in all four cardiac chambers and to assess associations with NT-proBNP and cardiac troponin T (hsTnT) in patients with HCM.

Methods

This retrospective study included 144 HCM patients and 16 healthy controls with CMR at 1.5 T. Analyses were performed on standard steady-state free precession cine (SSFP) CMR data using a commercially available software. Global left ventricular (LV) strain was assessed as longitudinal (LV_LAX-GLS), circumferential (LV_LAX-GCS) and radial strain (LV_LAX-GRS) on long -axis (LAX) and as LV_SAX-GCS and LV_SAX-GRS on short- axis (SAX). Right ventricular (RV-GLS), left atrial (LA-GLS) and right atrial (RA-GLS) strain were assessed on LAX.

Results

We found LV_LAX-GLS [− 18.9 (− 22.0, − 16.0), − 23.5 (− 25.5, − 22.0) %, p = 0.0001), LV_SAX-GRS [86.8 (65.9–115.5), 119.6 (91.3–143.7) %, p = 0.001] and LA_LAX-GLS [LA_2CH-GLS 29.2 (19.1–37.7), LA_2CH-GLS 38.2 (34.3–47.1) %, p = 0.0036; LA_4CH-GLS 22.4 (14.6–30.7) vs. LA_4CH-GLS 33.4 (28.4–37.3) %, p = 0.0033] to be impaired in HCM compared to healthy controls despite normal LVEF. Furthermore, LV and LA strain parameters were impaired in HCM with elevated NT-proBNP and/or hsTnT, despite preserved LVEF compared to HCM with normal biomarker levels. There was a moderate correlation of LV and LA CMR-FT with levels of NT-proBNP and hsTnT.

Conclusion

CMR-FT reveals LV and LA dysfunction in HCM despite normal LVEF. The association between impaired LV strain and elevated NT-proBNP and hsTnT indicates a link between unapparent functional abnormalities and disease severity in HCM.

Graphic abstract

Typical CMR-FT findings in patients with hypertrophic cardiomyopathy

Compressed sensing acceleration of cardiac cine imaging allows reliable and reproducible assessment of volumetric and functional parameters of the left and right atrium

Objectives

To compare volumetric and functional parameters of the atria derived from highly accelerated compressed sensing (CS)–based cine sequences in comparison to conventional (Conv) cine imaging.

Methods

CS and Conv cine sequences were acquired in 101 subjects (82 healthy volunteers (HV) and 19 patients with heart failure with reduced ejection fraction (HFrEF)) using a 3T MR scanner in this single-center study. Time-volume analysis of the left (LA) and right atria (RA) were performed in both sequences to evaluate atrial volumes and function (total, passive, and active emptying fraction). Inter-sequence and inter- and intra-reader agreement were analyzed using correlation, intraclass correlation (ICC), and Bland-Altman analysis.

Results

CS-based cine imaging led to a 69% reduction of acquisition time. There was significant difference in atrial parameters between CS and Conv cine, e.g., LA minimal volume (LAVmin) (Conv 24.0 ml (16.7–32.7), CS 25.7 ml (19.2–35.2), p < 0.0001) or passive emptying fraction (PEF) (Conv 53.9% (46.7–58.4), CS 49.0% (42.0–54.1), p < 0.0001). However, there was high correlation between the techniques, yielding good to excellent ICC (0.76–0.99) and small mean of differences in Bland-Altman analysis (e.g. LAVmin − 2.0 ml, PEF 3.3%). Measurements showed high inter- (ICC > 0.958) and intra-rater (ICC > 0.934) agreement for both techniques. CS-based parameters (PEF AUC = 0.965, LAVmin AUC = 0.864) showed equivalent diagnostic ability compared to Conv cine imaging (PEF AUC = 0.989, LAVmin AUC = 0.859) to differentiate between HV and HFrEF.

Conclusion

Atrial volumetric and functional evaluation using CS cine imaging is feasible with relevant reduction of acquisition time, therefore strengthening the role of CS in clinical CMR for atrial imaging.

Key Points

• Reliable assessment of atrial volumes and function based on compressed sensing cine imaging is feasible.

• Compressed sensing reduces scan time and has the potential to overcome obstacles of conventional cine imaging.

• No significant differences for subjective image quality, inter- and intra-rater agreement, and ability to differentiate healthy volunteers and heart failure patients were detected between conventional and compressed sensing cine imaging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-021-07830-z.

Computational fluid dynamics of the right atrium: Assessment of modelling criteria for the evaluation of dialysis catheters

Central venous catheters are widely used in haemodialysis therapy, having to respect design requirements for appropriate performance. These are placed within the right atrium (RA); however, there is no prior computational study assessing different catheter designs while mimicking their native environment. Here, a computational fluid dynamics model of the RA, based on realistic geometry and transient physiological boundary conditions, was developed and validated. Symmetric, split and step catheter designs were virtually placed in the RA and their performance was evaluated by: assessing their interaction with the RA haemodynamic environment through prediction of flow vorticity and wall shear stress (WSS) magnitudes (1); and quantifying recirculation and tip shear stress (2). Haemodynamic predictions from our RA model showed good agreement with the literature. Catheter placement in the RA increased average vorticity, which could indicate alterations of normal blood flow, and altered WSS magnitudes and distribution, which could indicate changes in tissue mechanical properties. All designs had recirculation and elevated shear stress values, which can induce platelet activation and subsequently thrombosis. The symmetric design, however, had the lowest associated values (best performance), while step design catheters working in reverse mode were associated with worsened performance. Different tip placements also impacted on catheter performance. Our findings suggest that using a realistically anatomical RA model to study catheter performance and interaction with the haemodynamic environment is crucial, and that care needs to be given to correct tip placement within the RA for improved recirculation percentages and diminished shear stress values.

Persistent end-diastolic forward flow after pulmonary valve replacement in patients with repaired tetralogy of Fallot

 

OBJECTIVES

The clinical significance of persistent end-diastolic forward flow (EDFF) after pulmonary valve replacement (PVR) remains unclear in patients with repaired tetralogy of Fallot. This study aimed to identify the characteristics of these patients and the impact of persistent EDFF on outcomes.

METHODS

Of 46 consecutive patients who underwent PVR for moderate to severe pulmonary regurgitation between 2003 and 2019, 23 (50%) did not show EDFF before PVR [group (-)]. In the remaining 23 patients with EDFF before PVR, EDFF was diminished after PVR in 13 (28%) [group (+, -)] and persisted in 10 (22%) [group (+, +)]. The following variables were compared between these 3 groups: (i) preoperative right ventricular (RV) and right atrial volumes measured by magnetic resonance imaging, haemodynamic parameters measured by cardiac catheterization and the degree of RV myocardial fibrosis measured by RV biopsy obtained at PVR and (ii) the post-PVR course, development of atrial arrhythmia and need for intervention.

RESULTS

A high RV end-diastolic pressure, a greater right atrial volume index and a greater RV end-systolic volume index before PVR and a high degree of RV fibrosis were significantly associated with persistent EDFF 1 year after PVR. Persistent EDFF was a significant risk factor for postoperative atrial tachyarrhythmia, and catheter ablation and pacemaker implantation were required more frequently in these patients.

CONCLUSIONS

Persistent EDFF after PVR could predict a worse prognosis, especially an increased risk of arrhythmia. Close follow-up is required in patients with persistent EDFF for early detection of arrhythmia and prompt reintervention if necessary.

CLINICAL TRIAL REGISTRATION NUMBER

Institutional review board of Osaka University Hospital, number 16105.

Improving CT assessment for pulmonary hypertension in patients with severe aortic stenosis, correlation with right heart catheterization

PURPOSE

To identify CT parameters useful for assessment of pulmonary hypertension (PH) in patients with severe aortic stenosis (AS).

MATERIALS AND METHODS

Retrospective study of 165 patients who had undergone right heart catheterization (RHC), and CTA of the thorax for preoperative aortic valve replacement (TAVR) planning. These were divided into groups based on mean pulmonary artery (PA) pressure (mPAP) of 25 mm Hg on RHC (85 cases and 80 controls). Diameters of main pulmonary artery diameter (MPAD), left pulmonary artery (LPA), right pulmonary artery (RPA), and maximal long axis and short axis diameters of the right atrium (RA) and ventricle (RV) were measured on the axial plane. Univariate and multivariate statistical analysis was utilized to identify metrics predictive of PH.

RESULTS

MPAD, LPA, and RPA were higher in subjects with mPAP >25 mm Hg (p < 0.0001 for all). Thresholds of 30.5 mm for MPAD (68.4% sensitivity, 82.7% specificity), and 27.5 mm for LPA and RPA (LPA: 51.9% sensitivity, 78.8% specificity; RPA: 62.0% sensitivity, 78.8% specificity) provided the best discrimination of elevated mPAP. Compared to literature values for MPAD (28.9 mm in men and 26.9 mm in women), these thresholds provide lower sensitivity but greatly increased specificity. Inclusion of RA enlargement to MPAD increased specificity to 98.5%, while inclusion of RV enlargement increased specificity to 100%.

CONCLUSION

Threshold to identify PH in patients with AS using PA enlargement is higher than previously reported range for normal. Inclusion of RA and RV enlargement improves the ability of CT to more accurately identify PH in patients with AS.

Standardised computed tomographic assessment of left atrial morphology and tissue thickness in humans

AIMS

Left atrial (LA) remodelling is a common feature of many cardiovascular pathologies and is a sensitive marker of adverse cardiovascular outcomes. The aim of this study was to establish normal ranges for LA parameters derived from coronary computed tomographic angiography (CCTA) imaging using a standardised image processing pipeline to establish normal ranges in a previously described cohort.

METHODS

CCTA imaging from 193 subjects recruited to the Budapest GLOBAL twin study was analysed. Indexed LA cavity volume (LACVi), LA surface area (LASAi), wall thickness and LA tissue volume (LATVi) were calculated. Wall thickness maps were combined into an atlas. Indexed LA parameters were compared with clinical variables to identify early markers of pathological remodelling.

RESULTS

LACVi is similar between sexes (31 ml/m2 v 30 ml/m2) and increased in hypertension (33 ml/m2 v 29 ml/m2, p = 0.009). LASAi is greater in females than males (47.8 ml/m2 v 45.8 ml/m2 male, p = 0.031). Median LAWT was 1.45 mm. LAWT was lowest at the inferior portion of the posterior LA wall (1.14 mm) and greatest in the septum (median = 2.0 mm) (p < 0.001). Conditions known to predispose to the development of AF were not associated with differences in tissue thickness.

CONCLUSIONS

The reported LACVi, LASAi, LATVi and tissue thickness derived from CCTA may serve as reference values for this age group and clinical characteristics for future studies. Increased LASAi in females in the absence of differences in LACVi or LATVi may indicate differential LA shape changes between the sexes. AF predisposing conditions, other than sex, were not associated with detectable changes in LAWT.Clinical trial registration:http://www.ClinicalTrials.gov/NCT01738828.

Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update

Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.

Cardiovascular disease in women: insights from magnetic resonance imaging

The presentation and identification of cardiovascular disease in women pose unique diagnostic challenges compared to men, and underrecognized conditions in this patient population may lead to clinical mismanagement.This article reviews the sex differences in cardiovascular disease, explores the diagnostic and prognostic role of cardiovascular magnetic resonance (CMR) in the spectrum of cardiovascular disorders in women, and proposes the added value of CMR compared to other imaging modalities. In addition, this article specifically reviews the role of CMR in cardiovascular diseases occurring more frequently or exclusively in female patients, including Takotsubo cardiomyopathy, connective tissue disorders, primary pulmonary arterial hypertension and peripartum cardiomyopathy. Gaps in knowledge and opportunities for further investigation of sex-specific cardiovascular differences by CMR are also highlighted.

A publicly available virtual cohort of four-chamber heart meshes for cardiac electro-mechanics simulations

Computational models of the heart are increasingly being used in the development of devices, patient diagnosis and therapy guidance. While software techniques have been developed for simulating single hearts, there remain significant challenges in simulating cohorts of virtual hearts from multiple patients. To facilitate the development of new simulation and model analysis techniques by groups without direct access to medical data, image analysis techniques and meshing tools, we have created the first publicly available virtual cohort of twenty-four four-chamber hearts. Our cohort was built from heart failure patients, age 67±14 years. We segmented four-chamber heart geometries from end-diastolic (ED) CT images and generated linear tetrahedral meshes with an average edge length of 1.1±0.2mm. Ventricular fibres were added in the ventricles with a rule-based method with an orientation of -60° and 80° at the epicardium and endocardium, respectively. We additionally refined the meshes to an average edge length of 0.39±0.10mm to show that all given meshes can be resampled to achieve an arbitrary desired resolution. We ran simulations for ventricular electrical activation and free mechanical contraction on all 1.1mm-resolution meshes to ensure that our meshes are suitable for electro-mechanical simulations. Simulations for electrical activation resulted in a total activation time of 149±16ms. Free mechanical contractions gave an average left ventricular (LV) and right ventricular (RV) ejection fraction (EF) of 35±1% and 30±2%, respectively, and a LV and RV stroke volume (SV) of 95±28mL and 65±11mL, respectively. By making the cohort publicly available, we hope to facilitate large cohort computational studies and to promote the development of cardiac computational electro-mechanics for clinical applications.

Impact of right atrium dimension on adverse outcome after pulmonary valve replacement in repaired Tetralogy of Fallot patients

The hemodynamic impact of residual pulmonary regurgitation (PR) in repaired Tetralogy of Fallot (rTOF) has been well demonstrated. However, markers driving the decision making process to indicate the ideal timing of pulmonary valve replacement (PVR) are still uncertain. Furthermore, very few studies have included the right atrium (RA) dilatation as a preoperative risk factor for post-PVR clinical adverse outcome. The aim of this study was to investigate the impact of pre-PVR right atrial dilation on adverse outcomes in rTOF. We retrospectively reviewed from our CMR database all rTOF patients who underwent CMR study before and after PVR. Detailed clinical and surgical history were collected, in addition to imaging data. The composite primary and secondary post-PVR end points were also recorded. The study cohort consisted of 41 patients (mean age at PVR repair 27.4 ± 10 years). As expected, end-diastolic and end-systolic right ventricle (RV) volumes significantly decreased after PVR (p < 0.001). The RV reverse remodeling, defined by ΔRVEDVi and ΔRVESVi, was associated with both pre-PVR RVEDVi and RVESVi. The higher the pre-PVR RV volumes, more the RV reverse remodeling will be obtained post-surgery. Patients who experienced an adverse outcome were older at pre-PVR, they had a higher Nt-ProBNP, worse VO₂/kg/min, more significant tricuspid regurgitation and more dilated RA. The association with the RA dilatation persists and becomes even more significant if we exclude patients who had tricuspid repair beside RVOT surgical reconstruction. Besides RV volumes and function, RA dimensions may play a pivotal role in the decision making of TOF patients.

Accuracy of Non-Electrocardiographically Gated Thoracic CT Angiography for Right Atrial and Right Ventricular Enlargement

PURPOSE

To assess the role of long-axis (LA) and short-axis (SA) measurements of the right atrium (RA) and right ventricle (RV) at non-electrocardiographically (ECG) gated thoracic CT angiography for identification of RA enlargement and RV enlargement.

MATERIALS AND METHODS

This study was a retrospective case review of 138 patients who underwent both non-ECG-gated CT angiography and ECG-gated CT angiography concurrently from November 2016 through November 2018. The SA and LA of the RA and RV were measured by two observers blinded to the ECG-gated CT angiography data. ECG-gated CT angiography-derived RA end-systolic and RV end-diastolic volumes were used as standard of reference to derive cutoff values for diagnosis of RA and RV enlargement.

RESULTS

In this study, 138 patients were evaluated (70 men, 68 women; mean age, 70.0 years ± 18.4 [standard deviation]; mean body mass index, 29.3 kg/m² ± 8.1). Of these patients, ECG-gated CT angiography revealed 36.2% had RA enhancement and 19.0% had RV enhancement. The best predictor of RA enhancement was the product of atrial LA and SA measurements, for which a threshold value of 3210 mm² yielded a 94% sensitivity and 81.8% specificity (area under the curve [AUC], 0.92). A threshold of 55.5 mm for LA diameter had 86% sensitivity and 78.4% specificity in identifying RA enlargement. RV enlargement could be predicted if the SA diameter was greater than 48.5 mm (76.9% sensitivity and 64.9% specificity) and with a body surface area indexed value of 27.0 mm/m² (92.3% sensitivity and 74.8% specificity [AUC, 0.87]).

CONCLUSION

RA and RV enlargement can be accurately diagnosed by using non-ECG-gated CT angiography.© RSNA, 2019Supplemental material is available for this article.

EXPRESS: Statement on imaging and pulmonary hypertension from the Pulmonary Vascular Research Institute (PVRI)

Pulmonary hypertension (PH) is highly heterogeneous and despite treatment advances it remains a life-shortening condition. There have been significant advances in imaging technologies, but despite evidence of their potential clinical utility, practice remains variable, dependent in part on imaging availability and expertise. This statement summarizes current and emerging imaging modalities and their potential role in the diagnosis and assessment of suspected PH. It also includes a review of commonly encountered clinical and radiological scenarios, and imaging and modeling-based biomarkers. An expert panel was formed including clinicians, radiologists, imaging scientists, and computational modelers. Section editors generated a series of summary statements based on a review of the literature and professional experience and, following consensus review, a diagnostic algorithm and 55 statements were agreed. The diagnostic algorithm and summary statements emphasize the key role and added value of imaging in the diagnosis and assessment of PH and highlight areas requiring further research.

Fundamental Characterization of Conductive Intracardiac Communication for Leadless Multisite Pacemaker Systems

OBJECTIVE

A new generation of leadless cardiac pacemakers effectively overcomes the main limitations of conventional devices, but only offer single-chamber pacing, although dual-chamber or multisite pacing is highly desirable for most patients. The combination of several leadless pacemakers could facilitate a leadless multisite pacemaker but requires an energy-efficient wireless communication for device synchronization. This study investigates the characteristics of conductive intracardiac communication between leadless pacemakers to provide a basis for future designs of leadless multisite pacemaker systems.

METHODS

Signal propagation and impedance behavior of blood and heart tissue were examined by in vitro and in vivo measurements on domestic pig hearts and by finite-element simulations in the frequency range of 1 kHz to 1 MHz.

RESULTS

A better signal transmission was obtained for frequencies higher than 10 kHz. The influence of a variety of practical parameters on signal transmission could be identified. A larger distance between pacemakers increases signal attenuation. A better signal transmission is obtained through larger inter-electrode distances and a larger electrode surface area. Furthermore, the influence of pacemaker encapsulation and relative device orientation was assessed.

CONCLUSION

This study suggests that conductive intracardiac communication is well suited to be incorporated in leadless pacemakers. It potentially offers very low power consumption using low communication frequencies.

SIGNIFICANCE

The presented technique enables highly desired leadless multisite pacing in near future.

Age-related changes of right atrial morphology and inflow pattern assessed using 4D flow cardiovascular magnetic resonance: results of a population-based study

BACKGROUND

To assess age-related changes of blood flow and geometry of the caval veins and right atrium (RA) using 4D flow cardiovascular magnetic resonance (CMR) data obtained in a population-based study.

METHODS

An age-stratified sample (n = 126) of the population of the city of Freiburg, Germany, underwent transthoracic echocardiography and electrocardiogram-triggered and navigator-gated 4D flow CMR at 3 Tesla covering the caval veins and right heart. Study participants were divided into three age groups (1:20-39; 2:40-59; and 3:60-80 years of age). Analysis planes were placed in the superior and inferior caval vein. Subsequently, RA morphology and three-dimensional blood inflow pattern was assessed.

RESULTS

Blood flow of the RA showed a clockwise rotating helix without signs of turbulence in younger subjects. By contrast, such rotation was absent in 12 subjects of group 3 and turbulences were significantly more frequent (p < 0.001). We observed an age-related shift of the caval vein axis. While the outlets of the superior and inferior caval veins were facing each other in group 1, lateralization occurred in older subjects (p < 0.001). A convergence of axes was observed from lateral view with facing axes in older subjects (p = 0.004). Finally, mean and peak systolic blood flow in the caval veins decreased with age (group 3 < 2 < 1).

CONCLUSIONS

We have provided reference values of 4D CMR blood flow for different age groups and demonstrated the significant impact of age on hemodynamics of the RA inflow tract. This effect of aging should be taken into account when assessing pathologic conditions of the heart in the future.

Validation of Right Atrial Area as a Measure of Right Atrial Size and Normal Values of in Healthy Pediatric Population by Two-Dimensional Echocardiography

Right atrial (RA) size is a prognostic indicator for heart failure and cardiovascular death in adults. Data regarding use of RA area (RAA) by two-dimensional echocardiography as a surrogate for RA size and allometric modeling to define appropriate indexing of the RAA are lacking. Our objective was to validate RAA as a reliable measure of RA size and to define normal reference values by transthoracic echocardiography (TTE) in a large population of healthy children and develop Z-scores using a validated allometric model for indexing RAA independent of age, sex, and body size. Agreement between RAA and volume by 2D, 3D TTE, and MRI was assessed. RAA not volume by 2D TTE is an excellent surrogate for RA size. RAA/BSA¹ has an inverse correlation with BSA with a residual relationship to BSA (r = - 0.54, p < 0.0001). The allometric exponent (AE) derived for the entire cohort (0.85) also fails to eliminate the residual relationship. The entire cohort divided into two groups with a BSA cut-off of 1 m² to provide the best-fit allometric model (r = 0). The AE by least square regression analysis for each group is 0.95 and 0.88 for BSA < 1 m² and > 1 m², respectively, and was validated against an independent sample. The mean indexed RAA ± SD for BSA ≤ 1 m² and > 1 m² is 9.7 ± 1.3 cm² and 8.7 ± 1.3 cm², respectively, and was used to derive Z-scores. RAA by 2D TTE is superior to 2D or 3D echocardiography-derived RA volume as a measure of RA size using CMR as the reference standard. RAA when indexed to BSA¹, decreases as body size increases. The best-fit allometric modeling is used to create Z scores. RAA/BSA^0.95 for BSA < 1 m² and RAA/BSA^0.88 for those with BSA > 1 m² can be used to derive Z scores.

Immediate and Midterm Cardiac Remodeling After Surgical Pulmonary Valve Replacement in Adults With Repaired Tetralogy of Fallot: A Prospective Cardiovascular Magnetic Resonance and Clinical Study

BACKGROUND

Pulmonary valve replacement (PVR) in patients with repaired tetralogy of Fallot provides symptomatic benefit and right ventricular (RV) volume reduction. However, data on the rate of ventricular structural and functional adaptation are scarce. We aimed to assess immediate and midterm post-PVR changes and predictors of reverse remoeling.

METHODS

Fifty-seven patients with repaired tetralogy of Fallot (age ≥16 y; mean age, 35.8±10.1 y; 38 male) undergoing PVR were prospectively recruited for cardiovascular magnetic resonance performed before PVR (pPVR), immediately after PVR (median, 6 d), and midterm after PVR (mPVR; median, 3 y).

RESULTS

There were immediate and midterm reductions in indexed RV end-diastolic volumes and RV end-systolic volumes (RVESVi) (indexed RV end-diastolic volume pPVR versus immediately after PVR versus mPVR, 156.1±41.9 versus 104.9±28.4 versus 104.2±34.4 mL/m²; RVESVi pPVR versus immediately after PVR versus mPVR, 74.9±26.2 versus 57.4±22.7 versus 50.5±21.7 mL/m²; P<0.01). Normal postoperative diastolic and systolic RV volumes (the primary end point) achieved in 70% of patients were predicted by a preoperative indexed RV end-diastolic volume ≤158 mL/m² and RVESVi ≤82 mL/m². RVESVi showed a progressive decrease from baseline to immediate to midterm follow-up, indicating ongoing intrinsic RV functional improvement after PVR. Left ventricular ejection fraction improved (pPVR versus mPVR, 59.4±7.6% versus 61.9±6.8%; P<0.01), and right atrial reverse remodeling occurred (pPVR versus mPVR, 15.2±3.4 versus 13.8±3.6 cm²/m²; P<0.01). Larger preoperative RV outflow tract scar was associated with a smaller improvement in post-PVR RV/left ventricular ejection fraction. RV ejection fraction and peak oxygen uptake predicted mortality (P=0.03) over a median of 9.5 years of follow-up.

CONCLUSIONS

Significant right heart structural reverse remodeling takes place immediately after PVR, followed by a continuing process of further biological remodeling manifested by further reduction in RVESVi. PVR before RVESVi reaches 82 mL/m² confers optimal chances of normalization of RV function.

Mathematical modelling of the maternal cardiovascular system in the three stages of pregnancy

In this study, a mathematical model of the female circulation during pregnancy is presented in order to investigate the hemodynamic response to the cardiovascular changes associated with each trimester of pregnancy. First, a preliminary lumped parameter model of the circulation of a non-pregnant female was developed, including the heart, the systemic circulation with a specific block for the uterine district and the pulmonary circulation. The model was first tested at rest; then heart rate and vascular resistances were individually varied to verify the correct response to parameter alterations characterising pregnancy. In order to simulate hemodynamics during pregnancy at each trimester, the main changes applied to the model consisted in reducing vascular resistances, and simultaneously increasing heart rate and ventricular wall volumes. Overall, reasonable agreement was found between model outputs and in vivo data, with the trends of the cardiac hemodynamic quantities suggesting correct response of the heart model throughout pregnancy. Results were reported for uterine hemodynamics, with flow tracings resembling typical Doppler velocity waveforms at each stage, including pulsatility indexes. Such a model may be used to explore the changes that happen during pregnancy in female with cardiovascular diseases.

Reference value of left and right atrial size and phasic function by SSFP CMR at 3.0 T in healthy Chinese adults

The size and function of the left atrium (LA) and right atrium (RA) are related closely with the prognosis of cardiovascular diseases. However, their normal reference values, as measured by cardiac magnetic resonance (CMR), are not well established in Chinese populations. Healthy Chinese subjects (n = 135, 66 males, age 23–83 years) without cardiovascular risk factors were recruited. We imaged the LA and RA of all subjects using short axis and long axis slices by steady-state free precession (SSFP) sequences using a 3.0T scanner. The size and functional parameters were measured. Age and gender differences in LA were further explored. The normal reference values of atrial dimensions, volumes, and empty fractions (EFs) were provided by short axis (SAX) and area-length methods. Volumes and EFs derived by the area-length method showed correlated well with those derived by the by SAX method, but significantly underestimated the volumes (all P < 0.001) and overestimated the LA EFs (all P < 0.001). Atrial dimensions and volumes were generally larger in males. Conduit EFs and total EFs showed gender differences. Most atrial parameters correlated with age. In general, our results showed that gender and age have considerable impact on LA and RA size and function.

Right atrial volume by cardiovascular magnetic resonance predicts mortality in patients with heart failure with reduced ejection fraction

Background

Right Atrial Volume Index (RAVI) measured by echocardiography is an independent predictor of morbidity in patients with heart failure (HF) with reduced ejection fraction (HFrEF). The aim of this study is to evaluate the predictive value of RAVI assessed by cardiac magnetic resonance (CMR) for all-cause mortality in patients with HFrEF and to assess its additive contribution to the validated Meta-Analysis Global Group in Chronic heart failure (MAGGIC) score.

Methods and results

We identified 243 patients (mean age 60 ± 15; 33% women) with left ventricular ejection fraction (LVEF) ≤ 35% measured by CMR. Right atrial volume was calculated based on area in two- and four -chamber views using validated equation, followed by indexing to body surface area. MAGGIC score was calculated using online calculator. During mean period of 2.4 years 33 patients (14%) died. The mean RAVI was 53 ± 26 ml/m²; significantly larger in patients with than without an event (78.7±29 ml/m² vs. 48±22 ml/m², p<0.001). RAVI (per ml/m²) was an independent predictor of mortality [HR = 1.03 (1.01–1.04), p = 0.001]. RAVI has a greater discriminatory ability than LVEF, left atrial volume index and right ventricular ejection fraction (RVEF) (C-statistic 0.8±0.08 vs 0.55±0.1, 0.62±0.11, 0.68±0.11, respectively, all p<0.02). The addition of RAVI to the MAGGIC score significantly improves risk stratification (integrated discrimination improvement 13%, and category-free net reclassification improvement 73%, both p<0.001).

Conclusion

RAVI by CMR is an independent predictor of mortality in patients with HFrEF. The addition of RAVI to MAGGIC score improves mortality risk stratification.

Comparison of Two Central Venous Pressure Control Strategies to Prevent Atrial Fibrillation After Coronary Artery Bypass Grafting

BACKGROUND:

Atrial fibrillation (AF) takes place in 10-40% of patients undergoing coronary artery bypass grafting (CABG), and increases cardiovascular mortality. Enlargement of atrial chambers is associated with increased AF incidence, so patients with higher central venous pressure (CVP) are expected to have larger atrial distension, which increases AF incidence.

OBJECTIVE:

To compare post-CABG AF incidence, following two CVP control strategies.

METHODS:

Interventional, randomized, controlled clinical study. The sample comprised 140 patients undergoing CABG between 2011 and 2015. They were randomized into two groups, G15 and G20, with CVP maintained ≤ 15 cmH2O and ≤ 20 cmH2O, respectively.

RESULTS:

70 patients were included in each group. The AF incidence in G15 was 8.57%, and in G20, 22.86%, with absolute risk reduction of 14.28%, and number needed to treat (NNT) of 7 (p = 0.03). Mortality (G15 = 5.71%; G20 = 11.42%; p = 0.07), hospital length of stay (G15 = 7.14 days; G20 = 8.21 days; p = 0.36), number of grafts (median: G15 = 3, G2 = 2; p = 0.22) and cardiopulmonary bypass use (G15 = 67.10%; G20 = 55.70%; p = 0.22) were statistically similar. Age (p = 0.04) and hospital length of stay (p = 0.001) were significantly higher in patients who developed AF in both groups.

CONCLUSION:

Keeping CVP low in the first 72 post-CABG hours reduces the relative risk of AF, and may be useful to prevent AF after CABG.

FUNDAMENTO:

A fibrilação atrial (FA) ocorre em 10-40% dos pacientes submetidos a cirurgia de revascularização miocárdica (RM), e eleva a mortalidade cardiovascular. Como o aumento dos átrios está associado ao aumento da incidência de FA, espera-se que pacientes com pressão venosa central (PVC) mais alta tenham maior distensão atrial, o que eleva a incidência dessa arritmia.

OBJETIVO:

Comparar a incidência de FA em pós-operatório de RM, seguindo duas estratégias de controle de PVC.

MÉTODOS:

Estudo clínico randomizado controlado intervencionista. A amostra foi composta por 140 pacientes submetidos a RM entre 2011 e 2015. Os pacientes foram randomizados em dois grupos, G15 e G20, mantidos com PVC máxima de 15 cmH2O e 20 cmH2O, respectivamente.

RESULTADOS:

Foram incluídos 70 pacientes em cada grupo. A incidência da arritmia em G15 foi de 8,57% e, no G20, de 22,86%, com redução de risco absoluto de 14,28% e número necessário para tratar (NNT) de 7 (p = 0,03). Mortalidade (G15 = 5,71%; G20 = 11,42%; p = 0,07), tempo de internamento (G15 = 7,14 dias; G20 = 8,21 dias; p = 0,36), número de enxertos (medianas: G15 = 3, G2 = 2; p = 0,22) e uso de circulação extracorpórea (G15 = 67,10%; G20 = 55,70%; p = 0,22) mostraram-se estatisticamente semelhantes. A idade (p = 0,04) e o tempo de internamento (p = 0,001) foram significativamente maiores nos pacientes que desenvolveram FA nos dois grupos.

CONCLUSÃO:

Manter a PVC com valores mais baixos nas primeiras 72h após a cirurgia de RM reduz o risco relativo de FA e pode ser uma ferramenta útil na prevenção da FA após RM.

Reference ranges for cardiac structure and function using cardiovascular magnetic resonance (CMR) in Caucasians from the UK Biobank population cohort

BACKGROUND

Cardiovascular magnetic resonance (CMR) is the gold standard method for the assessment of cardiac structure and function. Reference ranges permit differentiation between normal and pathological states. To date, this study is the largest to provide CMR specific reference ranges for left ventricular, right ventricular, left atrial and right atrial structure and function derived from truly healthy Caucasian adults aged 45-74.

METHODS

Five thousand sixty-five UK Biobank participants underwent CMR using steady-state free precession imaging at 1.5 Tesla. Manual analysis was performed for all four cardiac chambers. Participants with non-Caucasian ethnicity, known cardiovascular disease and other conditions known to affect cardiac chamber size and function were excluded. Remaining participants formed the healthy reference cohort; reference ranges were calculated and were stratified by gender and age (45-54, 55-64, 65-74).

RESULTS

After applying exclusion criteria, 804 (16.2%) participants were available for analysis. Left ventricular (LV) volumes were larger in males compared to females for absolute and indexed values. With advancing age, LV volumes were mostly smaller in both sexes. LV ejection fraction was significantly greater in females compared to males (mean ± standard deviation [SD] of 61 ± 5% vs 58 ± 5%) and remained static with age for both genders. In older age groups, LV mass was lower in men, but remained virtually unchanged in women. LV mass was significantly higher in males compared to females (mean ± SD of 53 ± 9 g/m2 vs 42 ± 7 g/m2). Right ventricular (RV) volumes were significantly larger in males compared to females for absolute and indexed values and were smaller with advancing age. RV ejection fraction was higher with increasing age in females only. Left atrial (LA) maximal volume and stroke volume were significantly larger in males compared to females for absolute values but not for indexed values. LA ejection fraction was similar for both sexes. Right atrial (RA) maximal volume was significantly larger in males for both absolute and indexed values, while RA ejection fraction was significantly higher in females.

CONCLUSIONS

We describe age- and sex-specific reference ranges for the left ventricle, right ventricle and atria in the largest validated normal Caucasian population.