Improved Prognostic Performance of Right Atrial Pressure-Corrected Cardiac Power Output in Pulmonary Hypertension and Heart Failure with Preserved Ejection Fraction

Cardiac power output (CPO) is a powerful predictor of adverse outcomes in heart failure (HF). However, the original formula of CPO included the difference between mean arterial pressure and right atrial pressure (RAP). The prognostic performance of RAP-corrected CPO (CPORAP) remains unknown in heart failure with preserved ejection fraction (HFpEF). We studied 101 HF patients with a left ventricular ejection fraction > 40% who had pulmonary hypertension due to left heart disease. CPORAP was significantly more discriminating than CPO in predicting outcomes (Delong test, P = 0.004). Twenty-five (24.8%) patients presented with dis-concordantly high CPORAP and low CPO when stratified by the identified CPORAP threshold of 0.547 W and the accepted CPO threshold of 0.803 W. These patients had the lowest RAP, and their cumulative incidence was comparable with those with concordantly high CPO and CPORAP (P = 0.313). CPORAP might identify patients with right ventricular involvement, thereby providing better prognostic performance than CPO in HFpEF.

Assessment of Right Atrial Function Measured with Cardiac MRI Feature Tracking for Predicting Outcomes in Patients with Dilated Cardiomyopathy

Background Right atrial (RA) function strain is increasingly acknowledged as an important predictor of adverse events in patients with diverse cardiovascular conditions. However, the prognostic value of RA strain in patients with dilated cardiomyopathy (DCM) remains uncertain. Purpose To evaluate the prognostic value of RA strain derived from cardiac MRI (CMR) feature tracking (FT) in patients with DCM. Materials and Methods This multicenter, retrospective study included consecutive adult patients with DCM who underwent CMR between June 2010 and May 2022. RA strain parameters were obtained using CMR FT. The primary end points were sudden or cardiac death or heart transplant. Cox regression analysis was used to determine the association of variables with outcomes. Incremental prognostic value was evaluated using C indexes and likelihood ratio tests. Results A total of 526 patients with DCM (mean age, 51 years ± 15 [SD]; 381 male) were included. During a median follow-up of 41 months, 79 patients with DCM reached the primary end points. At univariable analysis, RA conduit strain was associated with the primary end points (hazard ratio [HR], 0.82 [95% CI: 0.76, 0.87]; P < .001). In multivariable Cox analysis, RA conduit strain was an independent predictor for the primary end points (HR, 0.83 [95% CI: 0.77, 0.90]; P < .001). A model combining RA conduit strain with other clinical and conventional imaging risk factors (C statistic, 0.80; likelihood ratio, 92.54) showed improved discrimination and calibration for the primary end points compared with models with clinical variables (C statistic, 0.71; likelihood ratio, 37.12; both P < .001) or clinical and imaging variables (C statistic, 0.75; likelihood ratio, 64.69; both P < .001). Conclusion CMR FT-derived RA conduit strain was an independent predictor of adverse outcomes among patients with DCM, providing incremental prognostic value when combined in a model with clinical and conventional CMR risk factors. Published under a CC BY 4.0 license. Supplemental material is available for this article.

Right Atrial Function Role in Tricuspid Regurgitation-Related Systemic Venous Congestion

Tricuspid regurgitation (TR) is a frequent valvular pathology and when significant, may cause systemic venous congestion (SC). The right atrium (RA) is an intermediate structure between the tricuspid valve and the venous system and its role in SC is not yet defined. A total of 116 patients with a measurable TR effective regurgitant orifice area (EROA) and regurgitant volume (RVol) were selected from 2020 to 2022. SC was estimated by echocardiography using inferior vena cava diameter and estimated right atrial pressure (eRAP) and by clinical congestive features. TR grade was mild in 23 patients (20%), moderate in 53 patients (46%), and severe in 40 patients (34%). There was a significant decrease in RA function measured by strain with increasing TR severity (p <0.001). There was a marked difference in RA strain between the groups with eRAP >10 and ≤10 mm Hg (25 ± 11% vs 11 ± 7%, p <0.0001). Variables independently associated with inferior vena cava diameter were RA strain (β -0.532, p <0.001), RA volume indexed (β 0.249, p = 0.002), RVol (β 0.229, p = 0.005) and EROA (β 0.185, p = 0.016), and independently associated with eRAP >10 mm Hg were EROA (odds ratio [OR] 1.024, 95% confidence interval [CI] 1.002 to 1.046), RVol (OR 1.039, 95% CI 1.007 to 1.072) and RA strain (OR 0.863, 95% CI 0.794 to 0.940). The addition of RA strain to models containing EROA or RVol significantly improved the power of the model. RA strain was independently associated with the presence of 3 or more congestive features. In conclusion, echocardiographic and clinical signs of SC are frequent in higher degrees of TR, and RA function seems to play a key role in modulating the downstream effect of TR.

Right atrial function early after tetralogy of Fallot repair

Diastolic dysfunction after repair for Tetralogy of Fallot (TOF) is associated with adverse long-term outcomes. Right atrial (RA) mechanics as a proxy of right ventricular (RV) diastolic function in the early post-operative period after surgical repair for TOF has not been reported. We sought to evaluate RA and RV strain prior to hospital discharge after TOF repair and to identify important patient factors associated with strain using a machine learning method. Single center retrospective cohort study of TOF patients undergoing surgical repair, with analysis of RA and RV strain from pre-and post-operative echocardiograms. RA function was assessed by the peak RA strain, systolic RA strain rate, early diastolic RA strain rate and RA emptying fraction. RV systolic function was measured by global longitudinal strain. Pre- and post-operative values were compared using Wilcoxon rank sum test. Gradient boosted machine (GBM) models were used to identify the most important predictors of post-operative strain. In total, 153 patients were enrolled, median age at TOF repair 3.5 months (25th-75th percentile: 2.2- 5.2), mostly male (67%), and White (64.1%). From pre-to post-operative period, there was significant worsening in all RA parameters and in RV strain. GBM models identified patient, anatomic, and surgical factors that were strong predictors of post-operative RA and RV strain. These factors included pulmonary valve and branch pulmonary artery Z scores, birth weight, gestational age and age at surgery, pre-operative RV fractional area change and oxygen saturation, type of outflow tract repair, duration of cardiopulmonary bypass, and early post-operative partial arterial pressure of oxygen. There is significant worsening in RA and RV strain early after TOF repair, indicating early alteration in diastolic and systolic function after surgery. Several patient and operative factors influence post-operative RV function. Most of the factors described are not readily modifiable, however they may inform pre-operative risk-stratification. The clinical application of RA strain and the prognostic implication of these early changes merit further study.

[Application values of right atrial volume, myocardial strain and strain rate in evaluating right atrial function in patients with essential hypertension with normal left ventricular ejection fraction]

Objective: To explore the application values of right atrial (RA) volume, myocardial strain and strain rate in evaluating right atrial functions in patients with essential hypertension (EHT) with normal left ventricular ejection fraction (LVEF). Methods: We retrospectively collected a total of 126 EHT patients with normal LVEF, including 66 males and 60 females, age from 18 to 83(48±15) years from the Affiliated Changzhou No.2 People's Hospital with Nanjing Medical University from March, 2018 to May, 2020. According to the left ventricular mass index, those patients were divided into without left ventricle hypertrophy (LVH) group (n=66) and LVH group (n=60), and 83 healthy volunteers were enrolled as control group, which including 42 males and 41 females, age from 14 to 88 (48±16) years. The total, passive and active RA emptying fraction (total RAEF, passive RAEF and active RAEF) were measured by using RA volumes method. The RA strain (S-reservoir, S-conduit, S-booster pump) and the strain rate (SR-reservoir, SR-conduit, SR-booster pump) were measured by two-dimensional speckle tracking echocardiography. Total RAEF, S-reservoir, and Sr-reservoir represented the reservoir function, while passive RAEF, S-conduit, and Sr-conduit represented the conduit function, and active RAEF, S-booster pump and Sr-booster pump represented the booster pump function, respectively. Than the values between the EHT patients and normal subjects, and the values among the EHT patients without LVH, EHT patients without LVH and normal subjects were compared. Results: The value of active RAEF was significantly lower in EHT patient than normal controls (40.1%±10.5% vs 45.4%±11.1%,P=0.001). There were significant differences among EHT patients without LVH, EHT patients with LVH and normal subjects in passive RAEF and active RAEF (passive RAEF: 40.2%±9.3% vs 36.4%±10.7% vs 36.5%±9.4%, P=0.038, active RAEF: 39.8%±10.6% vs 40.4%±10.4% vs 45.4%±11.1%, P=0.002). There were significant differences in S-reservoir, S-conduit, S-booster pump, SR-reservoir, SR-conduit and SR-booster pump between EHT patients and normal subjects [S-reservoir: 34.8%±13.7% vs 45.0%±13.3%, S-conduit: 18.3%±9.4% vs 26.5%±9.6%, S-booster pump: 16.4%±7.3% vs 18.6%±7.1%, SR-reservoir: (1.6±0.6)/s vs (2.0±0.6)/s, SR-conduit: (-1.2±0.5)/s vs (-1.6±0.6)/s, SR-booster pump: (-1.7±0.6)/s vs (-2.3±0.6)/s; all P<0.05]. The trend tests showed normal controls achieved the largest the absolute values of S-reservoir, S-conduit, SR-reservoir, SR-conduit, SR-booster pump, followed by EHT patients without LVH and EHT patients with LVH(all P<0.001). Conclusions: Using RA volume, myocardial strain and strain rate can detect the RA impaired reservoir, conduit, and the booster pump functions in EHT patients with normal LVEF, and the RA functions were damaged more significantly in EHT patients with LVH.

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.

Association of right atrial structure with incident atrial fibrillation: a longitudinal cohort cardiovascular magnetic resonance study from the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

While studies of the left atrium (LA) have demonstrated associations between volumes and emptying fraction with atrial fibrillation (AF), the contribution of right atrial (RA) abnormalities to incident AF remains poorly understood.

OBJECTIVES

Assess the association between RA structure and function with incident AF using feature-tracking cardiovascular magnetic resonance (CMR).

METHODS

This is a prospective cohort study of all participants in the Multi-Ethnic Study of Atherosclerosis with baseline CMR, sinus rhythm, and free of clinical cardiovascular disease at study initiation. RA volume, strain, and emptying fraction in participants with incident AF (n = 368) were compared against AF-free (n = 2779). Cox proportional-hazards models assessed association between variables.

RESULTS

Participants were aged 60 ± 10 yrs., 55% female, and followed an average 11.2 years. Individuals developing AF had higher baseline RA maximum volume index (mean ± standard deviation [SD]: 24 ± 9 vs 22 ± 8 mL/m2, p = 0.002) and minimum volume index (13 ± 7 vs 12 ± 6 mL/m2, p < 0.001), and lower baseline RA emptying fraction (45 ± 15% vs 47 ± 15%, p = 0.02), peak global strain (34 ± 17% vs 36 ± 19%, p < 0.001), and peak free-wall strain (40 ± 23% vs 42 ± 26%, p = 0.049) compared with the AF-free population. After adjusting for traditional cardiovascular risk factors and LA volume and function, we found RA maximum volume index (hazards ratio [HR]: 1.13 per SD, p = 0.041) and minimum volume index (HR: 1.12 per SD, p = 0.037) were independently associated with incident AF.

CONCLUSIONS

In a large multiethnic population, higher RA volume indices were independently associated with incident AF after adjustment for conventional cardiovascular risk factors and LA parameters. It is unclear if this predictive value persists when additional adjustment is made for ventricular parameters.

Accuracy of right atrial pressure estimation using a multi-parameter approach derived from inferior vena cava semi-automated edge-tracking echocardiography: a pilot study in patients with cardiovascular disorders

The echocardiographic estimation of right atrial pressure (RAP) is based on the size and inspiratory collapse of the inferior vena cava (IVC). However, this method has proven to have limits of reliability. The aim of this study is to assess feasibility and accuracy of a new semi-automated approach to estimate RAP. Standard acquired echocardiographic images were processed with a semi-automated technique. Indexes related to the collapsibility of the vessel during inspiration (Caval Index, CI) and new indexes of pulsatility, obtained considering only the stimulation due to either respiration (Respiratory Caval Index, RCI) or heartbeats (Cardiac Caval Index, CCI) were derived. Binary Tree Models (BTM) were then developed to estimate either 3 or 5 RAP classes (BTM3 and BTM5) using indexes estimated by the semi-automated technique. These BTMs were compared with two standard estimation (SE) echocardiographic methods, indicated as A and B, distinguishing among 3 and 5 RAP classes, respectively. Direct RAP measurements obtained during a right heart catheterization (RHC) were used as reference. 62 consecutive 'all-comers' patients that had a RHC were enrolled; 13 patients were excluded for technical reasons. Therefore 49 patients were included in this study (mean age 62.2 ± 15.2 years, 75.5% pulmonary hypertension, 34.7% severe left ventricular dysfunction and 51% right ventricular dysfunction). The SE methods showed poor accuracy for RAP estimation (method A: misclassification error, ME = 51%, R² = 0.22; method B: ME = 69%, R² = 0.26). Instead, the new semi-automated methods BTM3 and BTM5 have higher accuracy (ME = 14%, R² = 0.47 and ME = 22%, R² = 0.61, respectively). In conclusion, a multi-parametric approach using IVC indexes extracted by the semi-automated approach is a promising tool for a more accurate estimation of RAP.

Development and assessment of a novel precordial lead system for accurate detection of right atrial and ventricular depolarization in dogs with various thoracic conformations

OBJECTIVE

To assess recording accuracy of right atrial and ventricular depolarization during 12-lead ECG when precordial lead V₁ was positioned at each of 5 locations on the thorax of dogs with various thoracic conformations.

ANIMALS

60 healthy client-owned dogs.

PROCEDURES

20 dogs were allocated to each of 3 groups (brachymorphic, mesomorphic, or dolichomorphic) on the basis of thoracic conformation. Each dog remained unsedated and was positioned in right lateral recumbency for a series of five 12-lead surface ECGs, with V₁ located adjacent to the sternum in the fifth intercostal space (ICS; control), at the costochondral junction (CCJ) of the right first ICS (1st-R), at the CCJ of the right third ICS, at the right third ICS where the thorax was the widest, and at the CCJ of the left first ICS. Electrocardiographic variables were compared among the 5 ECG tracings.

RESULTS

When V₁ was at the control location, the P wave was positive for all dogs; however, consistent recording of right atrial and ventricular depolarization (ie, R wave-to-S wave ratio [R/S] < 1) occurred more frequently for brachymorphic dogs (16/20) than for dolichomorphic (7/20) and mesomorphic (6/20) dogs. When V₁ was at the 1st-R location, the P wave was negative for most dogs, and R/S was < 1 for the majority of dogs in the brachymorphic (19/20), mesomorphic (17/20), and dolichomorphic (16/20) groups. The median R/S for V₁ at the 1st-R location was significantly lower than that for the other 4 V₁ locations.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that placement of V₁ at the 1st-R location provided correct evaluation of right atrial and ventricular depolarization in most dogs regardless of thoracic conformation.

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.

Noninvasive Assessment of Hemodynamic Status in HeartWare Left Ventricular Assist Device Patients: Validation of an Echocardiographic Approach

OBJECTIVES

The aim of this prospective study was to validate an echocardiographic protocol derived from 5 HeartWare left ventricular assist device (HVAD) patients for the noninvasive evaluation of right atrial pressure (RAP) and left atrial pressure (LAP) in HVAD patients.

BACKGROUND

Echocardiography is an invaluable tool to optimize medical treatment and pump settings and also for troubleshooting residual heart failure. Little is known about the echocardiographic evaluation of hemodynamic status in HVAD patients.

METHODS

Right heart catheterization and Doppler echocardiography were performed in 35 HVAD patients. Echocardiography-estimated RAP (eRAP) was assessed using inferior vena cava diameter, hepatic venous flow analysis, and tricuspid E/e' ratio. Echocardiography-estimated LAP was assessed using E/A ratio, mitral E/e' ratio, and deceleration time.

RESULTS

eRAP and estimated LAP significantly correlated with invasive RAP and LAP (respectively, r = 0.839, p < 0.001, and r = 0.889, p < 0.001) and accurately detected high RAP and high LAP (respectively, area under the curve 0.94, p < 0.001, and area under the curve 0.91, p < 0.001). High eRAP was associated with high LAP (area under the curve 0.92, p < 0.001) and correlated with death or hospitalization at 180 days (odds ratio: 8.2; 95% confidence interval: 1.1 to 21.0; p = 0.04). According to estimated LAP and eRAP, patients were categorized into 4 hemodynamic profiles. Fifteen patients (43%) showed the optimal unloading profile (normal eRAP and normal wedge pressure). This profile showed a trend toward a lower risk for adverse cardiac events at follow-up (odds ratio: 0.2; 95% confidence interval: 0.1 to 1.0; p = 0.05) compared with other hemodynamic profiles.

CONCLUSIONS

Doppler echocardiography accurately estimated hemodynamic status in HVAD patients. This algorithm reliably detected high RAP and LAP. Notably, high RAP was associated with high wedge pressure and adverse outcome. The benefit of noninvasive estimation of hemodynamic status in the clinical management of patients with left ventricular assist devices needs further evaluation.

Orthogonal P-wave morphology is affected by intra-atrial pressures

BACKGROUND

It has previously been shown that the morphology of the P-wave neither depends on atrial size in healthy subjects with physiologically enlarged atria nor on the physiological anatomical variation in transverse orientation of the left atrium. The present study aimed to investigate if different pressures in the left and right atrium are associated with different P-wave morphologies.

METHODS

38 patients with isolated, increased left atrial pressure, 51 patients with isolated, increased right atrial pressure and 76 patients with biatrially increased pressure were studied. All had undergone right heart catheterization and had 12-lead electrocardiographic recordings, which were transformed into vectorcardiograms for detailed P-wave morphology analysis.

RESULTS

Normal P-wave morphology (type 1) was more common in patients with isolated increased pressure in the right atrium while abnormal P-wave morphology (type 2) was more common in the groups with increased left atrial pressure (P = 0.032). Moreover, patients with increased left atrial pressure, either isolated or in conjunction with increased right atrial pressure, had significantly more often a P-wave morphology with a positive deflection in the sagittal plane (P = 0.004).

CONCLUSION

Isolated elevated right atrial pressure was associated with normal P-wave morphology while left-sided atrial pressure elevation, either isolated or in combination with right atrial pressure elevation, was associated with abnormal P-wave morphology.

Reliability of echocardiographic speckle-tracking derived bi-atrial strain assessment under different hemodynamic conditions

The aim of this study was to assess intra- and inter-observer variability of left (LA) and right atrial (RA) strain indices obtained by two-dimensional speckle-tracking echocardiography (2D-STE) in a healthy group of individuals at low-altitude and after rapid ascent to high-altitude in order to provoke altered systemic and pulmonary hemodynamics otherwise seen in various cardiac diseases. Twenty healthy subjects underwent transthoracic echocardiography during a baseline examination at low-altitude (424 m) as well as 7, 20 and 44 h after arrival at high-altitude (4559 m). Atrial strain indices (i.e. reservoir, conduit and contractile strain) were determined off-line by two independent observers. Intra- and inter-observer reproducibility of variables was assessed by intra-class correlation coefficients (ICCs), coefficients of variation and Bland Altman plots. Heart rate, systemic blood pressure and pulmonary artery pressure increased significantly from low-altitude to the first examination at high-altitude. Intra-observer ICCs were ≥0.90 except for RA conduit strain with an ICC of 0.86. The mean intra-observer differences were small and limits of agreement of relative differences were narrow for all atrial strain parameters (<3 and <16%, respectively). Inter-observer ICCs (0.80-0.90), mean biases and limits of agreement (<4 and <20%, respectively) were greater than intra-observer results for all parameters. Intra- and inter-obserer ICCs for all atrial strain variables did not differ between low- and high-altitude. 2D-STE-derived bi-atrial strain indices have excellent intra- and moderate inter-observer reproducibility with no effect of high-altitude-induced hemodynamic changes on reliability results.

Significant Drop in Right Atrial Pressure Does Not Influence Fractional Flow Reserve Coronary Assessment

The effect of a highly elevated level of right atrial filling pressure on fractional flow reserve (FFR) measurement remains unclear. Transcatheter tricuspid valve intervention, a recently introduced option for inoperable or high-risk patients, represents a unique model of in-vivo physiology to investigate the eventual influence of central venous pressure on coronary FFR measurements. The case is reported of a patient with a degenerated tricuspid surgical bioprosthesis who underwent transcatheter tricuspid valve-in-valve replacement and concomitant coronary functional assessment with FFR. In an experimental model, the significant fall in right atrial pressure did not influence FFR measurements in the presence of angiographically proven mild coronary artery disease.

Relation of Right Atrial Volume, Systemic Venous Dimensions, and Flow Patterns to Right Atrial Pressure in Infants and Children

Echocardiographic assessment of right atrial (RA) volume, inferior vena cava (IVC) diameter, and hepatic vein flow velocity independently correlate with the RA pressure by direct catheter measurement in adults. We prospectively collected invasive RA pressure measurements and echocardiographic data in infants and young children with the goal of developing a predictive model to noninvasively determine normal RA pressure. All subjects had a central venous catheter through which RA pressure could be transduced. Specific inclusion criteria consisted of (1) biventricular heart, (2) absence of inotropes, (3) sinus rhythm, and (4) at least 24 hours from surgery. Two-dimensional echocardiography (2DE)-Doppler and 3DE-Doppler were used to measure RA volume, systemic venous diameters, and flow velocity. Regression equations of RA pressure with RA volume, systemic venous size, and flow velocity were explored. Of 46 studies, 43 (93%) had echocardiograms adequate for analysis. RA pressure did not correlate with body surface area or age (p = 0.69, p = 0.87). The mean indexed RA volume by 3DE-Doppler was significantly higher than by 2DE (p <0.005). On multivariable analysis, only IVC systolic flow velocity and systolic 2D Simpson's derived indexed RA volume demonstrated significant independent correlation with RA pressure, resulting in the equation: RA pressure (mm Hg) = 7.35 - 0.0025 × IVC systolic flow velocity (cm/s) + 0.119 × indexed RA volume by systolic 2D Simpson's (ml/m²). RA pressure did not show correlation with systemic venous diameters or systolic and diastolic flow velocities in the SVC and hepatic veins. In conclusion, regression incorporating 2DE-derived RA volume and IVC systolic flow velocity provided the best noninvasive estimate of normal RA pressure in infants and children. The model derived requires validation in an independent sample.

Prolonged Sinus Pauses upon Termination of Paroxysmal Atrial Fibrillation: Abnormal Right Atrial Electrophysiologic and Electroanatomic Findings

The efficacy of pulmonary vein antral isolation for patients with prolonged sinus pauses (PSP) on termination of atrial fibrillation has been reported. We studied the right atrial (RA) electrophysiologic and electroanatomic characteristics in such patients. Forty patients underwent electroanatomic mapping of the RA: 13 had PSP (group A), 13 had no PSP (group B), and 14 had paroxysmal supraventricular tachycardia (control group C). Group A had longer P-wave durations in lead II than did groups B and C (115.5 ± 15.4 vs 99.5 ± 10.9 vs 96.5 ± 10.4 ms; P=0.001), and RA activation times (106.8 ± 13.8 vs 99 ± 8.7 vs 94.5 ± 9.1 s; P=0.02). Group A's PP intervals were longer during adenosine triphosphate testing before ablation (4.6 ± 2.3 vs 1.7 ± 0.6 vs 1.5 ± 1 s; P <0.001) and after ablation (4.7 ± 2.5 vs 2.2 ± 1.4 vs 1.6 ± 0.8 s; P <0.001), and group A had more complex electrograms (11.4% ± 5.4% vs 9.3% ± 1.6% vs 5.8% ± 1.6%; P <0.001). Compared with group C, group A had significantly longer corrected sinus node recovery times at a 400-ms pacing cycle length after ablation, larger RA volumes (100.1 ± 23.1 vs 83 ± 22.1 mL; P=0.04), and lower conduction velocities in the high posterior (0.87 ± 0.13 vs 1.02 ± 0.21 mm/ms; P=0.02) and high lateral RA (0.89 ± 0.2 vs 1.1 ± 0.35 mm/ms; P=0.04). We found that patients with PSP upon termination of atrial fibrillation have RA electrophysiologic and electroanatomic abnormalities that warrant post-ablation monitoring.

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.

[Assessment right atrial function in patients with systemic lupus erythematosus by speckle tracking and three-dimensional echocardiography]

Objective: To evaluate right atrial function in systemic lupus erythematosus (SLE) with normal pulmonary pressure by using two dimensional-speckle tracking imaging (2D-STI) and real-time three-dimensional echocardiography(RT-3DE). Methods: A totoal of 40 patients with SLE and 40 control subjects were collected between December 2011 and May 2014 from Ningbo Medical Treatment Center Lihuili Hospital. Right atrial global longitudinal strain (RAGLS) and all kinds of right atrium volume index (RAVI) were detected. Relationship between tricuspid annular plane systolic excursion(TAPSE), tricuspid annulus systolic peak velocity (S'), right ventricular myocardial performance index (RVMPI), E_TV/e'_TV and the right atrium parameters were analyzed. Results: SLE group's right atrium maximal volume index(RAVImax)(33.5±11.1) ml/m^2, right atrium minimal volume index (RAVImin)(13.2±4.5) ml/m^2, right atrium presystolic volume index (RAVIpre) (2.57±10.2) ml/m^2, right atrium total emptying volume index(RAVIt)(20.2±8.1)ml/m^2, right atrium active emptying volume index (RAVIa)(12.5±7.5) ml/m²) were increased .But right atrium passive emptying volume index(RAVIp)( 7.8±2.7) ml/m² and right atrial global longitudinal strain (RAGLS) (38.2%±7.7% ) were decreased (both P<0.05). RAGLS was positive correlated with S' and TAPSE, the r value were 0.565 and 0.445 respectively (both P<0.01). E_TV/e'_TV was positive correlated with RAVIpre, RAVIa, the r value were 0.469 and 0.481 respectively (both P<0.05). Conclusion: Detecting right atrial function by 2D-STI and RT-3DE could diagnose right atrial dysfunction in early stage of SLE patients with normal pulmonary pressure. The method is simple, has significant clinical value.

Vena cava compression syndrome in patients with obesity presenting with edema and thrombosis

OBJECTIVE

Obesity is a risk factor for cardiovascular disease and venous thrombosis. Previous studies have shown that in late pregnancy a compression of the inferior vena cava (VCI) leads to a hypotensive syndrome. The objective of this study was to explore the correlation between obesity and an elevated pressure in the VCI simulating obesity-induced vena cava compression syndrome.

METHODS

A left and right heart catheterization was performed in 29 patients. After right atrial pressure measurement, the catheter was pulled back through the VCI, and the pressure gradient between the thoracic and abdominal vena cava was measured. We determined the correlation between the BMI and the pressure gradient.

RESULTS

In 29 patients, a high BMI was associated with an increased pressure gradient between the thoracic and abdominal vena cava (r = 0.66). This correlation was particularly close in patients with a BMI >30 kg/m(2) (P = 0.0008). Two patients had complications such as recurrent thrombosis, with one of them having the highest pressure gradient of 16 mm Hg.

CONCLUSIONS

Because mechanical obstruction of the VCI leads to an increased risk for venous thrombosis in patients with obesity, this finding needs to be considered in the decision-making for interventional treatments like bariatric surgery.

Evaluation of right atrial function using right atrial speckle tracking analysis in patients with pulmonary artery hypertension

BACKGROUND

In patients with pulmonary artery hypertension (PAH), right ventricular pressure overload eventually causes right heart failure (RHF), leading to a poor prognosis. Right atrial (RA) overload and RA dysfunction occur in patients with PAH-complicated RHF.

OBJECTIVES

We evaluated RA function using right atrial longitudinal strain (RALS) by two-dimensional speckle tracking echocardiography (2D-STE) and investigated the association between RALS and the severity of RHF in patients with pulmonary artery hypertension (PAH) noninvasively.

METHODS

We performed 2D-STE in 56 PAH patients and 20 normal control subjects. The peak global RALS and peak global RA longitudinal strain rate (RALSR) were analyzed by 2D-STE. Simultaneous right heart catheterization was performed to determine the right atrial pressure (RAP) and cardiac index (CI).

RESULTS

Peak global RALS (34.6 ± 14.1 vs. 58.3 ± 9.9%, p < 0.0001) and peak global RALSR (2.5 ± 1.3 vs. 3.1 ± 1.2 s(-1), p < 0.0001) were significantly lower in PAH patients compared with normal controls. There was a significant negative correlation between peak global RALS and RAP (r = -0.8037, p < 0.0001). There was a significant positive correlation between peak global RALS and CI (r = 0.8179, p < 0.0001). Peak global RALSR was also correlated with RAP (r = -0.7308, p < 0.0001) and CI (r = 0.7596, p < 0.0001).

CONCLUSIONS

RALS and RALSR by 2D-STE were useful for noninvasive evaluation of RA dysfunction and the severity of RHF in patients with PAH.

Quantification of atrial dynamics using cardiovascular magnetic resonance: inter-study reproducibility

BACKGROUND

Cardiovascular magnetic resonance (CMR) offers quantification of phasic atrial functions based on volumetric assessment and more recently, on CMR feature tracking (CMR-FT) quantitative strain and strain rate (SR) deformation imaging. Inter-study reproducibility is a key requirement for longitudinal studies but has not been defined for CMR-based quantification of left atrial (LA) and right atrial (RA) dynamics.

METHODS

Long-axis 2- and 4-chamber cine images were acquired at 9:00 (Exam A), 9:30 (Exam B) and 14:00 (Exam C) in 16 healthy volunteers. LA and RA reservoir, conduit and contractile booster pump functions were quantified by volumetric indexes as derived from fractional volume changes and by strain and SR as derived from CMR-FT. Exam A and B were compared to assess the inter-study reproducibility. Morning and afternoon scans were compared to address possible diurnal variation of atrial function.

RESULTS

Inter-study reproducibility was within acceptable limits for all LA and RA volumetric, strain and SR parameters. Inter-study reproducibility was better for volumetric indexes and strain than for SR parameters and better for LA than for RA dynamics. For the LA, reservoir function showed the best reproducibility (intraclass correlation coefficient (ICC) 0.94-0.97, coefficient of variation (CoV) 4.5-8.2%), followed by conduit (ICC 0.78-0.97, CoV 8.2-18.5%) and booster pump function (ICC 0.71-0.95, CoV 18.3-22.7). Similarly, for the RA, reproducibility was best for reservoir function (ICC 0.76-0.96, CoV 7.5-24.0%) followed by conduit (ICC 0.67-0.91, CoV 13.9-35.9) and booster pump function (ICC 0.73-0.90, CoV 19.4-32.3). Atrial dynamics were not measurably affected by diurnal variation between morning and afternoon scans.

CONCLUSIONS

Inter-study reproducibility for CMR-based derivation of LA and RA functions is acceptable using either volumetric, strain or SR parameters with LA function showing higher reproducibility than RA function assessment. Amongst the different functional components, reservoir function is most reproducibly assessed by either technique followed by conduit and booster pump function, which needs to be considered in future longitudinal research studies.

Effect of body position and oxygen tension on foramen ovale recruitment

While there is an increased prevalence of stroke at altitude in individuals who are considered to be low risk for thrombotic events, it is uncertain how venous thrombi reach the brain. The patent foramen ovale (PFO) is a recruitable intracardiac shunt between the right and left atrium. We aimed to determine whether body position and oxygen tension affect blood flow through the PFO in healthy adults. We hypothesized that hypoxia and body positions that promote right atrial filling would independently recruit the PFO. Subjects with a PFO (n = 11) performed 11 trials, combining four different fractions of inhaled oxygen (FiO₂) (1.0, 0.21, 0.15, and 0.10) and three positions (upright, supine, and 45° head down), with the exception of FiO₂ = 0.10, while 45° head down. After 5 min in each position, breathing the prescribed oxygen tension, saline bubbles were injected into an antecubital vein and a four-chamber echocardiogram was obtained to evaluate PFO recruitment. We observed a high incidence of PFO recruitment in all conditions, with increased recruitment in response to severe hypoxia and some contribution of body position at moderate levels of hypoxia. We suspect that increased pulmonary vascular pressure, secondary to hypoxia-induced pulmonary vasoconstriction, increased right atrial pressure enough to recruit the PFO. Additionally, we hypothesize that the minor increase in breathing resistance that was added by the mouthpiece, used during experimental trials, affected intrathoracic pressure and venous return sufficiently to recruit the PFO.

Human atrial fibrillation initiates via organized rather than disorganized mechanisms

BACKGROUND

It is unknown how atrial fibrillation (AF) is actually initiated by triggers. Based on consistencies in atrial structure and function in individual patients between episodes of AF, we hypothesized that human AF initiates when triggers interact with deterministic properties of the atria and may engage organized mechanisms.

METHODS AND RESULTS

In 31 patients with AF, we mapped AF initiation after spontaneous triggers or programmed stimulation. We used 64-pole basket catheters to measure regional dynamic conduction slowing and to create biatrial activation maps during transitions to AF. Sixty-two AF initiations were recorded (spontaneous, n=28; induced, n=34). Notably, AF did not initiate by disorganized mechanisms, but by either a dominant reentrant spiral wave (76%) or a repetitive focal driver. Both mechanisms were located 21±17 mm from their triggers. AF-initiating spirals formed at the site showing the greatest rate-dependent slowing in each patient. Accordingly, in 10 of 12 patients with multiple observed AF episodes, AF initiated using spatially conserved mechanisms despite diverse triggers.

CONCLUSIONS

Human AF initiates from triggers by organized rather than disorganized mechanisms, either via spiral wave re-entry at sites of dynamic conduction slowing or via repetitive focal drivers. The finding that diverse triggers initiate AF at predictable, spatially conserved functional sites in each individual provides a novel deterministic paradigm for AF with therapeutic implications.

Isolated dilatation of the inferior vena cava

The diameter and collapsibility of the inferior vena cava (IVC) should be interpreted in consideration with other clinical and echocardiographic parameters before drawing definitive diagnostic conclusions. We report a case of a 46-year-old female with isolated IVC dilation and diminished inspiratory collapse without other abnormalities, and provide a brief review of the literature.

Evaluation of biatrial size and functions by different echocardiographic parameters in patients with acute coronary syndromes

After acute coronary syndromes (ACS), cardiac remodelling affecting not only ventricles but also both atria is an important problem associated with an increased risk for adverse cardiovascular outcomes. However, it is usually underestimated to evaluate atrial size and functions. The aim of the present study is to compare left and right atrial size and functions in ACS patients with healthy controls during transthoracic echocardiography by means of diameter, area and volume measurements, and pulsed-wave tissue Doppler imaging (TDI). 150 ACS patients (128 male, 22 female) and 25 healthy controls (19 male, 6 female) were enrolled into the study. Of the ACS patients, 75 had ST-segment elevation myocardial infarction (STEMI) and 75 had non-STEMI. Biatrial diameters, areas, and volumes were measured from different echocardiographic views. Atrial total emptying fraction and expansion index values were calculated from volume measurements. By the pulsed-wave TDI of the atrial walls; peak systolic (S'), peak early diastolic (E'), and peak late diastolic (A') velocities were measured. Almost all left atrial parameters for diameter, area, and volume measurements were higher in ACS patients. Similarly, they had higher values for the same right atrial parameters. Left and right atrial total emptying fraction and expansion index values were lower in ACS patients than controls. All left and right atrial walls had lower S' and E' velocities in ACS patients. ACS cause important alterations in the biatrial size and functions evaluated by echocardiographic diameter, area and volume measurements, and pulsed-wave TDI.

Surgery impacts right atrial function in tetralogy of Fallot

OBJECTIVE

To analyze the impact of surgery and pericardial integrity on right atrial function and total heart volume variation in the setting of pulmonary valve insufficiency.

METHODS

Right atrial function and total heart volume variation were analyzed in 2 subgroups of patients with pulmonary valve insufficiency compared with healthy controls: group 1 with surgically repaired tetralogy of Fallot (n = 20 patients) and group 2 after balloon angioplasty of pulmonary valve stenosis in patients with isolated valve disease without surgery (n = 7 patients). Volumetric analysis of magnetic resonance imaging data revealed parameters of atrial function (reservoir, conduit, and pump functions and cyclic volume change) and of total heart volume (end-diastolic and end-systolic total heart volume and the variation). Statistical analysis included uncorrected and corrected pairwise comparisons and the calculation of groupwise Pearson correlation coefficients.

RESULTS

In group 1 with a pulmonary regurgitation fraction of 31.0% ± 14.9%, right atrial function was clearly impaired, with reduced reservoir and elevated conduit function, and total heart volume variation was elevated to 13.9% ± 3.4%. In group 2 with a pulmonary regurgitation fraction of 22.8% ± 6.9%, the values were close to normal, with unaffected atrial function and a total heart volume variation of 9.9% ± 3.3%.

CONCLUSIONS

The hydrodynamic effect of pulmonary valve insufficiency alone is likely not the only reason for impaired right atrial function and elevated total heart volume variation in patients with tetralogy of Fallot; it is rather the scar in the right atrium, the injured pericardium, and the disease itself that are responsible for the energetically unfavorable alterations.

Correlation of natriuretic peptides and inferior vena cava size in patients with congestive heart failure

BACKGROUND

The inferior vena cava (IVC) diameter and degree of inspiratory collapse are used as echocardiographic indices in the estimation of right atrial pressure. Brain-natriuretic peptides (BNPs) are established biomarkers of myocardial wall stress. There is no information available regarding the association between the IVC diameter and BNPs in patients with heart failure and various degrees of systolic performance. The purpose of this investigation is to quantify the degree to which natriuretic peptides (BNP and N-terminal pro-B natriuretic peptide [NT-ProBNP]) and echocardiographic-derived indices of right atrial pressure correlate in this patient population.

METHODS

We examined 77 patients (mean age 61 ± 17 years, 44% male) with decompensated heart failure who underwent transthoracic echocardiography and, within a timeframe of 24 hours, determination of BNP and NT-ProBNP levels in venous blood. BNP and NT-ProBNP were analyzed after log transformation. The degree of association was measured by the correlation coefficient using the Pearson's method.

RESULTS

The mean ejection fraction was 50% ± 20%, and 33% of the study cohort had a remote history of heart failure. The mean IVC diameter was 1.85 cm ± 0.5, the mean BNP was 274 pg/mL, the confidence interval (CI) was 95% (95% CI: 197-382), and the mean NT-ProBNP was 1994 pg/mL (95% CI: 1331-2989). There was a positive, albeit small, association between IVC diameter and BNP (r = 0.24, 95% CI: 0.01-0.44; P = 0.03) and NT-ProBNP (r = 0.27, 95% CI: 0.05-0.47; P = 0.01). Among patients with different degrees of IVC collapse in response to inspiration, values for BNP and NT-ProBNP did not differ substantially (P = 0.36 and 0.46 for BNP and NT-ProBNP, respectively).

CONCLUSION

Natriuretic peptides correlate weakly with IVC size and do not predict changes in response to intrathoracic pressure.

Differential modulation of right ventricular strain and right atrial mechanics in mild vs. severe pressure overload

Increased right atrial (RA) and ventricular (RV) chamber volumes are a late maladaptive response to chronic pulmonary hypertension. The purpose of the current investigation was to characterize the early compensatory changes that occur in the right heart during chronic RV pressure overload before the development of chamber dilation. Magnetic resonance imaging with radiofrequency tissue tagging was performed on dogs at baseline and after 10 wk of pulmonary artery banding to yield either mild RV pressure overload (36% rise in RV pressure; n = 5) or severe overload (250% rise in RV pressure; n = 4). The RV free wall was divided into three segments within a midventricular plane, and circumferential myocardial strain was calculated for each segment, the septum, and the left ventricle. Chamber volumes were calculated from stacked MRI images, and RA mechanics were characterized by calculating the RA reservoir, conduit, and pump contribution to RV filling. With mild RV overload, there were no changes in RV strain or RA function. With severe RV overload, RV circumferential strain diminished by 62% anterior (P = 0.04), 42% inferior (P = 0.03), and 50% in the septum (P = 0.02), with no change in the left ventricle (P = 0.12). RV filling became more dependent on RA conduit function, which increased from 30 ± 9 to 43 ± 13% (P = 0.01), than on RA reservoir function, which decreased from 47 ± 6 to 33 ± 4% (P = 0.04), with no change in RA pump function (P = 0.94). RA and RV volumes and RV ejection fraction were unchanged from baseline during either mild (P > 0.10) or severe RV pressure overload (P > 0.53). In response to severe RV pressure overload, RV myocardial strain is segmentally diminished and RV filling becomes more dependent on RA conduit rather than reservoir function. These compensatory mechanisms of the right heart occur early in chronic RV pressure overload before chamber dilation develops.

Quantitative cardiovascular magnetic resonance in pregnant women: cross-sectional analysis of physiological parameters throughout pregnancy and the impact of the supine position

BACKGROUND

There are physiological reasons for the effects of positioning on hemodynamic variables and cardiac dimensions related to altered intra-abdominal and intra-thoracic pressures. This problem is especially evident in pregnant women due to the additional aorto-caval compression by the enlarged uterus. The purpose of this study was to investigate the effect of postural changes on cardiac dimensions and function during mid and late pregnancy using cardiovascular magnetic resonance (CMR).

METHODS

Healthy non-pregnant women, pregnant women at 20th week of gestation and at 32nd week of gestation without history of cardiac disease were recruited to the study and underwent CMR in supine and left lateral positions. Cardiac hemodynamic parameters and dimensions were measured and compared between both positions.

RESULTS

Five non-pregnant women, 6 healthy pregnant women at mid pregnancy and 8 healthy pregnant women at late pregnancy were enrolled in the study. In the group of non-pregnant women left ventricular (LV) cardiac output (CO) significantly decreased by 9% (p=0.043) and right ventricular (RV) end-diastolic volume (EDV) significantly increased by 5% (p=0.043) from the supine to the left lateral position. During mid pregnancy LV ejection fraction (EF), stroke volume (SV), left atrium lateral diameter and left atrial supero-inferior diameter increased significantly from the supine position to the left lateral position: 8%, 27%, 5% and 11%, respectively (p<0.05). RV EDV, SV and right atrium supero-inferior diameter significantly increased from the supine to the left lateral position: 25%, 31% and 13% (p<0.05), respectively. During late pregnancy a significant increment of LV EF, EDV, SV and CO was observed in the left lateral position: 11%, 21%, 35% and 24% (p<0.05), respectively. Left atrial diameters were significantly larger in the left lateral position compared to the supine position (p<0.05). RV CO was significantly increased in the left lateral position compared to the supine position (p<0.05).

CONCLUSIONS

During pregnancy positional changes affect significantly cardiac hemodynamic parameters and dimensions. Pregnant women who need serial studies by CMR should be imaged in a consistent position. From as early as 20 weeks the left lateral position should be preferred on the supine position because it positively affects venous return, SV and CO.

[Correlation of intracardiac pressures and electrical atrial potentials with morphology and function of overloaded atria assessed by echocardiography]

BACKGROUND

In patients with chronic complete heart block or single chamber pacing and preserved sinus depolarization, left and right atria (LA, RA) may suffer from increased intraatrial pressure resulting from atrioventricular dyssynchrony (AVDys), dilate and lose their contractile function. The purpose of the study was to find out whether any correlation exists between the echocardiographically measured LA, RA morphological and functional parameters on one hand and the intracardiac RA pressures and electrical potentials on the other hand in patients with chronic AVDys.

METHODS

In 26 pts (77 +/- 10 years, 16 males), where a chronic AVDys was the most important patophysiological mechanism of atrial overloading, the intraatrial pressures (atrial, right ventricular, pulmonary arterial and wedge pressure/PWP/) and electrical potentials (upper, middle, lower part of RA and RA appendage) were correlated with atrial diameters, volumes, ejection fraction and filling parameters.

RESULTS

There was a moderate inverse correlation between the LA ejection fraction and PWP: r = -0,489, p = 0,025 at a level of significance 0.05, but no relationship between PWP and LA size/volumes. No correlation between RA potentials or intracardiac pressures and RA morphologic or functional features were documented.

CONCLUSIONS

In this study, an inverse correlation between the capillary wedge pressure and left atrial ejection fraction in pts with chronic atrioventricular dyssynchrony was documented. No other correlation between echocardiographic parameters and intracardiac pressures or electrical potentials was found.

Natriuretic peptides and right atrial fibrosis in patients with paroxysmal versus persistent atrial fibrillation

Natriuretic peptides (NPs) are excellent diagnostic and prognostic markers of heart failure, but their roles in atrial fibrillation (AF), particularly of isolated cardiac valvular origin, are unclear. We assessed the mRNA and protein content of pro-atrial natriuretic peptide (pro-ANP) and pro-brain natriuretic peptide (pro-BNP) in right atrial appendages (RAAs) and their N-terminal fragments (nt-proANP and nt-proBNP) in the plasma of 30 patients with paroxysmal AF (PaAF) and 40 patients with persistent AF (PeAF) matched with 34 patients in sinus rhythm (SR) undergoing isolated valvular replacement. To explore the underlying mechanism, fibrosis related examinations were simultaneously carried out in RAAs. Unexpectedly, atrial expression of pro-NPs mRNA was notably augmented in the PaAF subgroup, but not so pronounced in the PeAF subgroup. Atrial content of pro-NPs proteins and plasma nt-proNPs, between which surprisingly strong positive correlations were found (pro-ANP and nt-proANP: r=0.918, p<0.001; pro-BNP and nt-proBNP: r=0.913, p<0.001), were increased analogously in PaAF and PeAF subgroups. We identified significantly increasing gradients of atrial collagen volume fraction (CVF), levels of collagen I and III in the SR, PaAF and PeAF groups, and convincing negative linear correlations between CVF, levels of collagen I and III, and atrial transcripts of pro-NPs. These findings suggest that the discordance between transcripts and protein contents of pro-NPs was possibly due to the more outstanding atrial fibrosis in PeAF, and that circulating nt-proNPs levels could reflect the corresponding atrial pro-NPs contents in this report.

Detection of elevated right atrial pressure using a simple bedside ultrasound measure

AIMS

Accurate assessment of right atrial pressure (RAP) often requires invasive measurement. With normal RAP, Valsalva increases right internal jugular vein (RIJV) cross sectional area (CSA) 20% to 30%. With high RAP, when venous compliance is low, we hypothesized that the increase in CSA would be blunted and could be detected non-invasively with bedside ultrasound.

METHODS AND RESULTS

RIJV ultrasound images were obtained in 67 patients undergoing right heart catheterization. The median RAP at end-expiration was 7 mm Hg (interquartile range [IQR] 5-9 mm Hg) in patients with normal RAP (n = 47) versus 15 mm Hg (IQR 12-22 mm Hg) in patients with elevated RAP (n = 20). With Valsalva, the median percent change in RIJV CSA was 35% (IQR 19%-79%) versus 5% (IQR 3%-14%) for normal and high RAP, respectively. By receiver operating curve analysis, a <17% increase in RIJV CSA with Valsalva predicted elevated RAP (> or =12 mmHg) with 90% sensitivity, 74% specificity, 94% negative predictive value, and 60% positive predictive value (area under the curve 0.86, P < .001).

CONCLUSIONS

An increase in RIJV CSA >17% during Valsalva effectively rules out elevated RAP. This simple bedside technique may be useful to assess central venous pressure and reduce the need for invasive pressure measurement.

Left ventricular diastolic collapse in low-pressure cardiac tamponade

A case of systemic hypotension with volume depletion not responding to intravenous fluids was found to have features of cardiac tamponade on two-dimensional (2-D) echocardiography. Intracardiac pressures were normal on cardiac catheterization. An interesting observation was the presence of left ventricular (LV) collapse on 2-D echocardiography. To the authors' best knowledge, such a case of low pressure cardiac tamponade with LV collapse has not been reported earlier.

Predictive values of the electrocardiogram in diagnosing pulmonary hypertension

OBJECTIVE

Determination of the prevalences and predictive values of specific electrocardiograms (ECG) criteria of right ventricular hypertrophy (RVH) or right atrial enlargement for pulmonary hypertension.

METHODS

We examined the ECG and trans-thoracic echocardiograms (TTE) of 372 patients who had TTE and 12-lead ECG, performed within 24 h interval, during a 12-month period. There were 282 consecutive adults with pulmonary hypertension (pulmonary artery systolic pressure (PASP) >30 mm Hg) and 90 subjects with normal cardiac anatomy and normal PASP. The mean age of patients with pulmonary hypertension was 74.0+/-11.0 years and 66% of them were females. The control subjects had a mean age of 56.3+/-17.5 years and 58.8% were females.

RESULTS

ECG patterns focusing on the R and S amplitudes and R/S ratio in V1 were more predictive of pulmonary hypertension than ECG patterns involving leads V5 and V6. In particular, each of the following ECG patterns had good positive predictive values for pulmonary hypertension (greater than 80%): R in I less than 2 mm+S in V1</=2 mm, R/S in V1 more than 1, R/S V6 less than 1, QRS axis more than 110 degrees , qR in V1. Right axis deviation with QRS axis more than 110 degrees had the best positive predictive value of severe pulmonary hypertension (PASP>/=60 mm Hg). Electrocardiographic criterion for right atrial enlargement was not found in any of the patients with pulmonary hypertension.

CONCLUSIONS

ECG criteria of RVH were rare in patients with pulmonary hypertension. ECG patterns focusing on the R and S amplitude in V1 and right axis deviation with QRS axis deviation>/=110 degrees had excellent positive predictive values of pulmonary hypertension. However, the absence of ECG criteria of RVH could not exclude with certainty the presence of pulmonary hypertension.

Simvastatin reduces platelet–endocardium adhesion in atrial fibrillation

OBJECTIVES

To evaluate the relationship between CD40/CD40L system and increased thrombogenesis in AF, and to test the effects of simvastatin treatment.

METHODS

In vitro study using human tissue, University Hospital (tertiary referral center). Experiments on right atrial segments obtained before the onset of cardiopulmonary bypass were done in either presence or absence of 5 microM simvastatin. Two groups of patients in either chronic atrial fibrillation or sinus rhythm at the time of cardiac surgery. The endocardial expression of CD40, the release of CD40L, and adhesion of platelets to endocardium. Additionally, the thickness of platelet aggregates and the platelet distribution on the endocardium were also evaluated.

RESULTS

Atrial fibrillation was associated with a significant increase of endocardial CD40 expression (293.1+/-55.1 pg/ml vs. 230.9+/-53.3 pg/ml, p<0.01), and platelet-endocardial adhesion compared with sinus rhythm atria (10.8+/-2.2 vs. 5.2+/-1.3 platelet CD41 AU p<0.01). At immunofluorescence about 62% of fibrillating endocardium was covered by platelets, compared with 12% of not sinus rhythm atria. Addition of simvastatin significantly reduced CD40 expression as well as platelet adhesion to fibrillating atria; its efficacy was not reversed by the addition of mevalonic acid.

CONCLUSIONS

Chronic atrial fibrillation acutely upregulates CD40 expression as well as platelet adhesion to the endocardium. Simvastatin is effective in modulating this expression, thus it may potentially contribute to reduce the risk of intra-atrial thrombus formation.

Atrial natriuretic peptide (ANP)-granules in the guinea pig atrial and auricular cardiocytes: an immunocytochemical and ultrastructural morphometric comparative study

The atrial natriuretic peptide (ANP) is a peptide hormone that is mainly produced in the cardiac atria, where it is stored within granules. It is known that the four regions of the atrial-auricular complex (two atria and two auricles) produce and store ANP in the granules. However, no report has been presented comparing the presence of ANP, and the number and diameter of atrial granules in the atria and auricles. ANP immunoreactivity was detected in cardiocytes from the four regions of the atrial-auricular complex. No differences were observed among the regions. The number of granules was greatest in the right atrium followed by the left atrium and left auricle and right auricle, in this order. The diameter of granules in the cardiocytes was significantly largest in the right atrium and reduced via the left auricle to the left atrium and right auricle. Both the number and diameter of the granules are larger in the right atrium in comparison with the other regions of the atrial-auricular complex, which leads to the supposition that this region is the one that most synthesizes and stores the ANP.

Reference Right Atrial Function Determined by Steady-State Free Precession Cardiovascular Magnetic Resonance

BACKGROUND

There is agreement that measurements of atrial volumes and ejection fraction (EF) are superior to atrial diameters for accurate determination of atrial size, follow up studies and prognosis. However, reference values for right atrial volumes and EF for cardiovascular magnetic resonance (CMR) have not been established but are crucial to identify patients with impaired right atrial function.

METHODS AND RESULTS

Atrial function was studied in 70 healthy subjects (52+/-16 years, 38 male) with both the standard short axis method (SA) and the area-length method (AL) using steady-state free precession gradient-echo cine imaging (SSFP). Intraobserver, interobserver (n=70) and interstudy (n=10) variability was assessed for both methods. Maximal volumes, minimal volumes and EF for SA and AL were 101.0+/-30.2 mL, 50.3+/-19 mL and 47.2+/-8.3%, and 103.2+/-32.6 mL, 50.8+/-20.2 mL and 51.4+/-9.2%, respectively. Maximal volumes, minimal volumes and EF were higher with AL than with SA (mean difference: 2.2+/-4.6 mL, 3.5+/-3.5 mL and 2.8+/-2.8%, respectively). Atrial function measurements were not related to gender (p>or=0.387) and age (rho<or=0.16) with either method. Intraobserver, interobserver and interstudy variability for volumes and EF was lower for SA compared to AL, with narrower limits of agreement. Analysis was faster with AL than with SA (62+/-18 s versus 7+/-2 minutes).

CONCLUSION

Normal ranges for right atrial function vary significantly between methods. AL is faster, but less reproducible than SA. Appropriate reference ranges should be used to differentiate normal from abnormal right atrial function.

Evolution of Right Cardiac Pressures During the First Year After Heart Transplantation

INTRODUCTION

Preoperative pulmonary hypertension is an adverse prognostic factor for early morbidity-mortality after heart transplantation (HT). The persistence of hypertension is likewise associated with a poorer patient prognosis. The present study investigated the evolution of right cardiac pressures in the first year after HT with respect to the background cardiac disease.

METHODS

This study of 60 consecutive patients subjected to HT analyzed the baseline clinical characteristics and mean right atrial and right ventricle systolic and diastolic pressures in a pre-HT study and during biopsies performed in the first 2 weeks as well as at 1, 3, 6, 9, and 12 months after transplantation. The study excluded retransplantations, heart and lung transplantations, and pediatric patients, as well as patients not subjected to biopsy because of early mortality.

RESULTS

The mean patient age was 50 years (83% males); 31.7% were diabetics, and 33% showed hypertension. The background heart disease was of ischemic origin in 35% of cases, and consisted of dilated myocardiopathy in 33%, with a mean left ventricle ejection fraction (LVEF) of 23% and a mean pulmonary artery systolic pressure of 50.1 mm Hg. During the postoperative course, an important decrease versus baseline was observed in right heart pressures as soon as 2 weeks post-HT, with a drop in right ventricle (RV) systolic pressure from 50.3 +/- 13.7 to 42.5 +/- 10.4 mm Hg (P = .013), and a drop in RV diastolic pressure from 17.4 +/- 5.8 to 14.2 +/- 4.1 mm Hg (P = .007). This decreased tendency continued to a more moderate extent to the third month, after which the pressures stabilized. The same behavior was observed in patients with diseases of ischemic origin and in those with dilated myocardiopathy.

CONCLUSIONS

In our series, right cardiac pressures showed an important decrease in the first days after HT, with stabilization by the third month--though without returning to normal values and without modifications in the first year after transplantation. No differences in this evolutive trend were seen according to the type of background heart disease.

Marked pleural effusion causing right atrial collapse simulating cardiac tamponade in a dog

A 16-month-old, female German shepherd dog was presented with severe bicavitary effusions. A diaphragmatic hernia was diagnosed by thoracic radiography. An echocardiogram performed prior to surgical repair of the hernia revealed signs of cardiac tamponade, with right atrial collapse, in the absence of pericardial effusion. Right atrial collapse was presumed to be secondary to severe pleural effusion. At surgery, no pericardial disease was identified. Surgical correction of the diaphragmatic hernia resulted in resolution of the pleural and peritoneal effusions. Follow-up echocardiography demonstrated resolution of the signs of cardiac tamponade.

Comparison of Noncontact and Electroanatomic Mapping to Identify Scar and Arrhythmia Late After the Fontan Procedure

Background— The right atrium late after the Fontan procedure is characterized by multiple complex arrhythmia circuits. We performed simultaneous electroanatomic and noncontact mapping to assess the accuracy of both systems to identify scar and arrhythmia.

Methods and Results— Mapping was performed in 26 patients aged 26.8±8.9 years, 18.7±4.4 years after Fontan surgery. The area and site of abnormal endocardium defined by electroanatomic mapping (bipolar contact electrogram <0.5 mV) were compared with those defined by noncontact mapping during sinus rhythm and by dynamic substrate mapping. Contact and reconstructed unipolar electrograms at a known distance from the multielectrode array, recorded by the noncontact system simultaneously at 452 endocardial sites, were compared for morphological cross correlation, timing difference, and amplitude. Mapping of arrhythmias was performed with both systems when possible. The median patient abnormal endocardium as defined by electroanatomic mapping covered 38.0% (range 16.7% to 97.8%) of the right atrial surface area, as opposed to 60.9% (range 21.3% to 98.5%) defined by noncontact mapping during sinus rhythm and 11.9% (range 0.4% to 67.3%) by dynamic substrate mapping. A significant decrease in electrogram cross correlation ( P =0.003), timing ( P =0.012), and amplitude ( P =0.003) of reconstructed electrograms, but not of contact electrograms ( P =0.742), was seen at endocardial sites >40 mm from the multielectrode array. Successful arrhythmia mapping by electroanatomic versus noncontact mapping was superior in 15 patients (58%), the same in 6 (23%), and inferior in 5 (19%; P =0.044).

Conclusions— Electroanatomic mapping is the superior modality for arrhythmia mapping late after the Fontan procedure. Noncontact mapping is limited by a significant reduction in reconstructed electrogram correlation, timing, and amplitude >40 mm from the multielectrode array and cannot accurately define areas of scar and low-voltage endocardium.

[Evaluation of atrial function by echocardiography]

In cardiology, ventricular function has extensively been studied, whereas atrial function received less attention. For such a reason atrial function is less known. The aim of this review was to summarize the role of atrial function and to explain how echocardiography and new echocardiographic-derived techniques may be of help to better study atrial function.

[Atrial electrical, contractile and structural remodeling induced by short-term atrial tachycardia in a canine model]

OBJECTIVE

To evaluate atrial remodeling induced by short term pacing in a canine model.

METHODS

Transvenous lead was inserted into the right atrial appendage of anesthetized mongrel dogs and paced for 5 hours at 450 bpm (n=12). Effective refractory period (ERP) and P-wave duration were measured before and post pacing and left ventricular pressure was monitored during the procedure. Echocardiography was performed to observe the presence or absence of spontaneous echo contrast and to assess the effect of rapid atrial pacing on atrial function. All measurements were obtained in sinus rhythm. Histology of the myocardium in left atrial trabeculae and appendages was examined by electron microscopy.

RESULTS

Compared to pre-pacing status, ERP was significantly reduced [(87.27 +/- 16.35) ms vs. (113.27 +/- 11.99) ms, P<0.01] at a cycle length of 300 ms, P-wave duration significantly increased [(56.09 +/- 8.62) ms vs. (52.09 +/- 7.63) ms, P<0.01], the peak velocity of atrial contraction significantly decreased [(48.92 +/- 10.80) cm/s vs. (59.25 +/- 9.37) cm/s, P<0.05] while heart rates and left ventricular pressure were not affected post five hours rapid atrial pacing. Pacing also induced significantly cellular ultrastructures changes including myofibrils loss, glycogen accumulation, mitochondria loss and swelling.

CONCLUSION

Short term pacing resulted in atrial electrical, contractile and structural remodeling.

Value of Tissue Doppler Myocardial Velocities of Tricuspid Lateral Annulus for the Diagnosis of Right Heart Failure in Patients with COPD

OBJECTIVE

Aim of this study was to investigate the value of systolic indices of tricuspid valve annular motion measured by tissue Doppler imaging for the diagnosis right ventricular failure in patients with chronic obstructive pulmonary disease (COPD).

METHODS

Patients with COPD with right heart failure symptoms and/or right ventricular dilatation were enrolled for the study. The control group consisted of age and sex matched patients referred to the echocardiography laboratory who had normal echocardiographic examination. Tricuspid valve annulus peak systolic velocity and myocardial acceleration during isovolumic contraction were recorded by tissue Doppler imaging.

RESULTS

IVA and Sa wave velocities were found to be significantly decreased in patients with right ventricular failure. For the prediction of right heart failure IVA <3.8 m/sec2 had 91% sensitivity, 80% specificity, 90% positive predictive value (PPV), and 82% negative predictive value (NPV) and Sa wave velocity <9.2 cm/sec had 80% sensitivity, 62% specificity, 75% PPV, and 68% NPV.

CONCLUSION

Tricuspid valve annular velocities measured by tissue Doppler imaging especially IVA, offer potential diagnostic value for the diagnosis of right heart failure in patients with COPD.