Right Ventricular Volumes In Patients Research Articles

Paradoxical increase in left atrial strains early after Covid-19 infection, a result of comprehensive recovery phase four-chamber strains study.

Cardiac consequences of Covid-19 infection have been mentioned in various studies as a serious risk factor for in-hospital mortality. However, the existence of residual cardiac dysfunction after the acute phase is seldom investigated especially in people without a history of specific medical disease.One hundred health care workers with positive reverse transcription-polymerase chain reaction test underwent comprehensive 2D and 3D echocardiography six to eight weeks after infection. Patients were classified into Mild, Moderate, and Severe groups based on their clinical characteristics of covid-19 infection, and all echocardiographic parameters were compared between the three groups. Left ventricular (LV) stroke volume index was reduced in all groups compared to normal ranges and was more prominent in the severe group (P-value < 0.05). 3D-derived LV global longitudinal strain (GLS) was significantly lower in the severe group in comparison to the mild group (- 19.3 ± 1 Vs. - 22.2 ± 2, P-value < 0.001) and correlated with highly sensitive CRP level at the acute phase. Left atrial (LA) strains, including LA peak strain, LA contraction strain, and LA reservoir strain, were considerably higher and LA volume index was significantly lower in the clinically severe covid patients. Analysis based on the extent of lung involvement showed significantly increased 3D-derived right ventricular volumes in patients who experienced severe pneumonia despite normalized strains. Conclusion: subclinical LV dysfunction as reduced stroke volume index and GLS exists in the early recovery phase of normal individuals with severe course of covid-19. LA function indicated by LA strains paradoxically increases in severe covid-19 infection in this phase.

Prognostic power of a new index of right ventricle-pulmonary artery coupling based on right ventricular volumes in patients with secondary tricuspid regurgitation

Abstract Background Although echocardiographic surrogates of right ventricular -arterial coupling (RVAC) have been reported to be associated with outcome in patients with moderate or severe secondary tricuspid regurgitation (STR), pulmonary artery systolic pressure (SPAP) is difficult to be estimated using echocardiography in patients with severe STR. Purpose Accordingly, we evaluated the predictive power of indexes of RVAC obtained using RV volumes measured using three-dimensional echocardiography (3DE). Methods We prospectively enrolled 180 patients with moderate or severe STR and complete two-dimensional, Doppler and 3DE data. The composite endpoint of death for any cause and heart failure hospitalization was used as primary outcome. Results After a median follow up of 24 months (IQR: 2–48), 72 patients (40%) reached the primary endpoint. Most of the echocardiographic parameters of RV function were associated with outcomes. Among the different parameters of RVAC, the receiver operating curve (ROC) analysis selected the ratio between (RV stroke volume [SV]-RegVol)/ RV End-systolic volume (ESV) (i.e. the RV forward SV/ESV) as the best predictor of the combined endpoint (AUC 0.80 [IC 95% 0.73–087]), with a threshold value of 0.49. Event-free survival of patients with RV forward SV/ESV higher and lower 0.49 has been performed (Figure 1). Multivariable Cox proportional hazards models were constructed (Figure 2). Adding sequentially the 3D-RVEF, TAPSE/SPAP and the forward RV SV/RV ESV on top of a basal model made of TR severity, New York Heart Association (NYHA) functional class and tricuspid anulus plane systolic excursion (TAPSE), the χ2 of the model increased from 40 to 43 (p=0.13) by adding 3D RVEF, from 43 to 46 (p=0.04) by adding TAPSE/SPAP, and from 46 to 51 (p=0.02) by adding RV forward SV/ESV. Severe TR (HR 3.53 [CI 95%: 1.84–6.78], p&amp;lt;0.001) and RV forward SV/ESV &amp;lt;0.49 (HR 2.45 [CI 95% 1.16–5.18], p=0.02) were the only parameters independently associated with outcome. Conclusions The RV forward SV/ESV is an index of RVAC obtained by 3DE which is independent from SPAP and it is strongly associated with the occurrence of death or heart failure hospitalization in patients with STR. Funding Acknowledgement Type of funding sources: None.

Contouring techniques in cardiac magnetic resonance assessment of right ventricular volumes in repaired tetralogy of fallot

IntroductionRight ventricular size and function on cardiac MRI provides thresholds for referral for pulmonary valve intervention in repaired Tetralogy of Fallot (RTOF). However, different contouring techniques are available to calculate right ventricular volumes and ejection fraction. It is not known whether these contouring techniques impact on threshold triggers for intervention. MethodsRight ventricular volumes on cardiac MRI for 24 consecutive subjects with RTOF were measured by two independent, experienced observers using three contouring techniques: smooth, detailed manual and detailed with semi-automated thresholding. ResultsEnd-diastolic and end-systolic volumes were significantly different between contouring techniques: largest for smooth contours, intermediate for thresholding and smallest for manual (EDV: smooth 233 ml, SD 105 ml; thresholding 215 ml, SD 95 ml; manual 206 ml, SD 94 ml; ESV: smooth 122 ml, SD 71 ml; thresholding 113 ml, SD 67 ml; manual 103 ml, SD 64 ml; p < 0.001 for all comparisons). Stroke volume from contours by thresholding correlated most strongly with velocity mapping (r = 0.87, p < 0.001). Interobserver agreement was strongest for smooth (end-diastolic volume ICC = 1.0 (confidence interval (CI):0.999–1.0, p < 0.001); end-systolic volume ICC = 0.999 (CI:0.994–1.0, p < 0.001) and weakest for manual contours ((end-diastolic volume ICC = 0.89 (CI:0.33–0.99, p = 0.01); end-diastolic volume ICC = 0.88 (CI:0.30–0.99, p = 0.01). Intra-observer agreement was uniformly high (ICC≥0.996, p < 0.001 for all). In 4/24 cases, contouring technique altered threshold triggers for pulmonary valve intervention. ConclusionsDifferences in contouring technique for measuring right ventricular volumes in patients with RTOF can affect thresholds triggering referral for pulmonary valve intervention. Standardisation of right ventricular measurement is needed in congenital cardiac MRI practice.

Impact of empagliflozin on right ventricular parameters and function among patients with type 2 diabetes

BackgroundSodium-glucose cotransporter 2 (SGLT2) inhibition reduces cardiovascular events in type 2 diabetes (T2DM) and is associated with a reduction in left ventricular (LV) mass index. However, the impact on right ventricular (RV) remodeling is unknown. Accordingly, the objective of this study was to assess the impact of SGLT2 inhibition on RV parameters and function in T2DM and coronary artery disease (CAD).MethodsIn EMPA-HEART CardioLink-6, 97 patients with T2DM and CAD were randomly assigned to empagliflozin 10 mg (n = 49) once daily or placebo (n = 48). Cardiac magnetic resonance imaging was performed at baseline and after 6 months. RV mass index (RVMi), RV end-diastolic and end-systolic volume index (RVEDVi, RVESVi) and RV ejection fraction (RVEF) were assessed in blinded fashion.ResultsAt baseline, mean RVMi (± SD) (11.8 ± 2.4 g/m2), RVEF (53.5 ± 4.8%), RVEDVi (64.3 ± 13.2 mL/m2) and RVESVi (29.9 ± 6.9 mL/m2) were within normal limits and were similar between the empagliflozin and placebo groups. Over 6 months, there were no significant differences in RVMi (− 0.11 g/m2, [95% CI − 0.81 to 0.60], p = 0.76), RVEF (0.54%, [95% CI − 1.4 to 2.4], p = 0.58), RVEDVi (− 1.2 mL/m2, [95% CI − 4.1 to 1.7], p = 0.41) and RVESVi (− 0.81 mL/m2, [95% CI − 2.5 to 0.90], p = 0.35) in the empaglifozin group as compared with the placebo group. In both groups, there was no significant correlation between RVMi and LVMi changes from baseline to 6 months.ConclusionsIn this post-hoc analysis, SGLT2 inhibition with empagliflozin had no impact on RVMi and RV volumes in patients with T2DM and CAD. The potentially differential effect of empagliflozin on the LV and RV warrants further investigation.Clinical Trial Registration: URL: https://www.clinicaltrials.gov/ct2/show/NCT02998970?cond=NCT02998970&draw=2&rank=1. Unique identifier: NCT02998970.

Usefulness of a New Transthoracic Echocardiography Score to Assess Right Ventricular Volumes in Patients with Repaired Tetralogy of Fallot.

Quantification of right ventricular (RV) volumes is essential in the follow-up of patients with a repaired tetralogy of Fallot (TOF). Cardiac magnetic resonance imaging (MRI) is the gold standard for RV assessment. However, given its cost and availability, the systematic use of MRI for serial longitudinal follow-up is limited. Herein, we examined the utility of a new two-dimensional (2D) transthoracic echocardiography (TTE) score (the RVDi score), which includes a compilation of 2D RV dimensions indexed to the body surface area, for predicting MRI-derived RV end-diastolic volume (RVEDV) in patients with a repaired TOF. Using our congenital heart clinic database, we retrospectively included 29 adult patients with a repaired TOF between February 2015 and July 2019. The 2D TTE RVDi score was compared with the MRI-derived RVEDV. Sensitivity and specificity values for predicting an RVEDVi > 150ml/m2 were calculated. The TTE RVDi score was highly correlated (r = 0.944) with MRI RVEDVi. A cut-off RVDi score set at 120mm/m2 predicted an RVEDVi > 150ml/m2 with a sensitivity of 83% and specificity of 94%. Use of a simple echocardiographic score based on indexed RV dimensions from 2D standard TTE imaging may complement the assessment of RV volumes in TOF patients.

Balloon pulmonary angioplasty reverse right ventricular remodelling and dysfunction in patients with inoperable chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis.

Right ventricular (RV) function is considered the major determinant of prognosis in patients with chronic thromboembolic pulmonary hypertension (CTEPH). The aim of this meta-analysis was to evaluate RV remodelling and function following balloon pulmonary angioplasty (BPA) in patients with inoperable CTEPH or persistent/recurrent pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). We reviewed all studies evaluating RV function by cardiac magnetic resonance (CMR) and/or echocardiography pre- and post-BPA from PubMed/Medline prior to 15 December 2019. Ten (299 patients) of the 29 studies retrieved met the inclusion criteria: 5 CMR and 5 echocardiography studies. The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Guidelines. Pooled data from CMR studies revealed BPA resulted in a significantly decreased RV end-diastolic volume index (weighted mean difference (WMD) - 28.33 ml/m2, p < 0.00001) and RV end-systolic volume index (WMD - 29.06 ml/m2, p < 0.00001) accompanied by an increased RV ejection fraction (RVEF, WMD 8.97%, p < 0.00001). Data from the echocardiography studies showed BPA resulted in decreased RV basal diameter (WMD - 0.37 cm, p = 0.0009) and an increase of RV fractional area change (WMD 5.97 %, p = 0.003), but improvements of tricuspid annular plane systolic excursion (TAPSE) and S' were not significant. BPA improves RVEF and decreases RV volumes in patients with inoperable CTEPH or persistent/recurrent PH after PEA. • Balloon pulmonary angioplasty improves RVEF and decreases RV volumes in patients with inoperable CTEPH or persistent/recurrent PH after PEA.

ACCURACY AND REPRODUCIBILITY OF RV VOLUMES MEASUREMENTS BY CMR USING SHORT AXIS VS LONG AXIS FOUR CHAMBER VIEWS IN PATIENTS AND RV PHANTOMS

Cardiac magnetic resonance (CMR) is the reference standard for right ventricular (RV) volume and function assessment. A stack of short-axis slices (SAX) is routinely used to measure RV volumes but basal slice selection is challenging due to tricuspid annular plane excursion. Long-axis views offer a clearer view of the tricuspid and pulmonary valve planes, eliminating the need for cross-referencing; yet, there is significant partial-volume variability due to large areas of tangential subendocardial borders not perpendicular to the plane. We assessed inter-reader agreement between two CMR Methods for measurement of RV volumes in patients. We also assessed agreement between CMR derived RV volumes and physical volume measurement obtained from explanted animal hearts. The study was conducted in both patients undergoing a clinically indicated scan (n=50), and in explanted pig hearts (n=10). The RV of explanted pig heart was injected with a plastic mold (Reprosil) and its reference volume was measured using water displacement. For patients and molds, the RV was imaged with a full stack of slices covering the heart in SAX and in 4-chamber long axis view (4ch). RV volumes were traced, from both imaging planes, by 2 readers for the patient data and 2-4 readers for the explant data. Inter-reader agreement of the RV volumes was assessed for SAX and 4ch using concordance correlation coefficients and Bland-Altman limits of agreement. For patients, SAX and 4ch had excellent inter-reader agreement with SAX having a slightly higher coefficient (Table). For explants, the inter-reader agreement was poor in comparison to patient data, with 4ch being the most reproducible method. When comparing CMR derived volumes to the reference volume of the molds, SAX views had the smallest limits of agreement, closely followed by 4ch. However both SAX and 4ch views overestimated the volume by about 4ml (Image). SAX is the most widely used and most accurate imaging plane for measurements of RV volumes, while inter-reader agreement is excellent for both SAX and 4ch. Both SAX and 4ch mildly overestimate RV volumes. The different morphology of the porcine heart and the challenges of tracing a still image may explain the poor inter-reader agreement for measuring the volume of explanted RV molds.View Large Image Figure ViewerDownload (PPT)

The echocardiographic paradox index in patients with a repaired tetralogy of Fallot

Objectives. Right ventricular (RV) volume is very important for pulmonary valve replacement after the total correction of tetralogy of Fallot (TOF), and we attempted to identify a convenient echocardiographic index that is well correlated with the volumetric data obtained through magnetic resonance imaging (MRI). Design. All patients who underwent cardiac MRI and echocardiography at Sejong General Hospital for evaluating pulmonary regurgitation after TOF total correction were included. The paradox index is the amount of paradoxical motion of the interventricular septum on the short-axis echocardiographic view. The paradox index was compared to several cardiac MRI indices. Results. Fifty-four patients were included. The paradox index for all patients was 1.22 ± 0.12 (1.06–1.67), and the index of the operation group was significantly higher than that of the non-operation group (1.26 ± 1.12 vs1.16 ± 1.12, P = 0.009). The paradox index was well correlated with the RV systolic and diastolic volumes, as measured by cardiac MRI (P = 0.002 and 0.003). Using a simple linear regression analysis, a paradox index of 1.24 corresponded to a RV diastolic volume of 160 ml/m2. Conclusions. The paradox index could help to indicate the time for an MRI analysis of the RV volume in patients after TOF total correction.

Three-Dimensional Modeling of the Right Ventricle from Two-Dimensional Transthoracic Echocardiographic Images: Utility of Knowledge-Based Reconstruction in Pulmonary Arterial Hypertension

Right ventricular (RV) volume and functional assessments are essential in the management of pulmonary arterial hypertension but are often difficult to perform. Three-dimensional (3D) echocardiography is limited by acoustic dropout of the RV free wall in dilated ventricles. The aim of this study was to test the hypothesis that knowledge-based reconstruction, a novel method for 3D modeling of RV endocardium from two-dimensional echocardiographic images, could provide accurate measurements of RV volumes and systolic function. Twenty-seven patients with pulmonary arterial hypertension were prospectively recruited for same-day echocardiography and cardiovascular magnetic resonance (CMR), which was used as a reference standard. Two-dimensional transthoracic echocardiographic images were acquired with 3D spatial localization equipment to allow 3D reconstruction. Image analysis was performed with dedicated software to obtain end-diastolic volume (EDV) and end-systolic volume (ESV) and RV ejection fraction (EF). The method of disks was used to determine RV volumes on CMR. Echocardiographic RV volumes correlated well with CMR (EDV, R= 0.87; ESV, R= 0.88; EF, R= 0.75). For interobserver analyses, coefficients of variability were 7.8 ± 7.0% for EDV, 10.2 ± 8.0% for ESV, and 15.4 ± 13.8% for EF. For intraobserver analyses, coefficients of variability were 7.1 ± 5.1% for EDV, 8.3 ± 7.0% for ESV, and 10.9 ± 9.2% for EF. On Bland-Altman analyses, volumes obtained on transthoracic echocardiography (TTE) were slightly larger than those obtained by CMR (ΔEDVTTE-CMR, 5.8 ± 33.7 mL; ΔESVTTE-CMR, 3.5 ± 27.8 mL), whereas EFs tended to be slightly higher by CMR (ΔEFCMR-TTE, 0.5 ± 6.5%). Knowledge-based reconstruction provides accurate and reproducible measurements of RV volumes in patients with pulmonary arterial hypertension. Larger studies are needed to confirm these results and to determine the practicality of this approach in daily practice and as an end point in clinical trials.

Effect of Branch Pulmonary Artery Stenosis on Right Ventricular Volume Overload in Patients With Tetralogy of Fallot After Initial Surgical Repair

Right ventricular (RV) volume overload secondary to pulmonary regurgitation is common in patients after initial repair of tetralogy of Fallot (TOF) and is associated with adverse long-term outcomes. The objective of the present study was to determine the effect of branch pulmonary artery stenosis on the RV volume in patients with repaired TOF. We reviewed 178 cardiac magnetic resonance imaging studies in patients with repaired TOF. We defined bilateral stenosis as a Nakata index of ≤200 mm(2)/m(2) and concordant branch pulmonary artery cross-sectional area, unilateral stenosis as 1 branch pulmonary artery cross-sectional area ≤100 mm(2)/m(2) and 1 branch pulmonary artery cross-sectional area >100 mm(2)/m(2), and restrictive physiology as prograde main pulmonary artery diastolic flow. Of the 178 patients, 20 (11%) had bilateral stenosis, 47 (26%) unilateral stenosis, and 111 (63%) had no stenosis. The RV end-diastolic volume was lower in patients with bilateral (125 ± 27 ml/m(2)) or unilateral (131 ± 43 ml/m(2)) stenosis than in those without stenosis (149 ± 35 ml/m(2), p = 0.021 and p = 0.019, respectively). The main pulmonary artery regurgitant fraction was greater in patients without stenosis (47%, range 2% to 69%) than in those with bilateral (33%, range 9% to 59%; p = 0.009) or unilateral stenosis (40%, range 0% to 71%; p = 0.033). Restrictive physiology was more common in patients with bilateral (13 of 15, 87%) or unilateral (21 of 38, 55%) stenosis than in those without stenosis (28 of 85, 33%; p <0.001 and p = 0.017, respectively). In conclusion, in patients with repaired TOF, bilateral and unilateral branch pulmonary artery stenosis was associated with a greater main pulmonary artery regurgitant fraction and smaller RV end-diastolic volume than those in patients without stenosis, likely owing to the development of restrictive physiology. Branch pulmonary artery stenosis might effectively delay the referral for pulmonary valve replacement.

Quantitative Analysis of Right Ventricular Function in Patients With Pulmonary Hypertension Using Three-Dimensional Echocardiography and a Two-Dimensional Summation Method Compared to Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is considered the clinical reference standard for measuring the right ventricular (RV) volume and ejection fraction, although real-time 3-dimensional echocardiography (RT3DE) would be a preferred method owing to its convenience and availability for repetitive examinations. However, the feasibility, accuracy, and reproducibility of RT3DE have not been fully examined. The present study sought to validate the correlation of RT3DE with a 2-dimensional summation method compared to MRI for assessing the function of the right ventricle and to evaluate the RV function in patients with pulmonary hypertension (PH). Thirty patients with PH underwent both RT3DE and MRI. The right ventricle was reconstructed with RT3DE using a 2-dimensional summation method to analyze the MRI measurements. The RV end-diastolic volume, RV end-systolic volume, and RV ejection fraction were measured. Fifteen normal subjects underwent the same echocardiographic protocol for comparison. The RV end-diastolic volume index, RV end-systolic volume index, and RV ejection fraction measured using RT3DE correlated well with those measured using MRI (R = 0.96, p <0.001; R = 0.96, p <0.001; p = 0.93, and p <0.001, respectively). All inter- and intraobserver variability values for the RV end-diastolic volume, RV end-systolic volume, and RV ejection fraction were <17%. Both the RV end-diastolic volume index and the RV end-systolic volume index were significantly enlarged in those with PH compared to those in the normal subjects (RVEDVI 123 ± 42 ml/m² vs 74 ± 12 ml/m²; RVESVI 86 ± 33 ml/m² vs 26 ± 5 ml/m² in those with PH and the normal subjects, respectively, p <0.0001). In contrast, the RV ejection fraction was significantly reduced in the patients with PH compared to that in the normal subjects (30 ± 12% vs 65 ± 6%, respectively, p <0.01). Thus, RT3DE with a 2-dimensional summation method might provide comparable and feasible measurements of the RV volume in patients with PH compared to MRI.

Comparison of Simpson's Method and Three-Dimensional Reconstruction for Measurement of Right Ventricular Volume in Patients With Complete or Corrected Transposition of the Great Arteries

The right ventricular (RV) volume is commonly measured from magnetic resonance images using Simpson's method from the stack of short-axis images acquired for analysis of the left ventricle. We compared the RV volume measured using Simpson's method to the RV volume measured using 3-dimensional reconstruction and the piecewise smooth subdivision surface (PSSS) method. We studied 6 normal subjects and 18 patients whose right ventricles carried a systemic pressure load, 1/2 with dexto-transposition of the great arteries repaired with an atrial baffle and 1/2 with levo-transposition of the great arteries. The right ventricle was reconstructed from manually traced borders from the short- and long-axis views using the PSSS method. Simpson's analysis was performed on short-axis views alone. The RV volumes were smaller when analyzed using Simpson's method than using the PSSS method. The underestimation averaged 12 +/- 19 ml (7 +/- 12% of PSSS volume; p <0.001), without a significant difference between the groups. The ejection fraction was similar using both methods in patients with transposition of the great arteries and was overestimated in normal subjects. Image review revealed that the volume underestimation using Simpson's method was more frequently due to difficulty in interpreting the basal short-axis images than the apical images. In conclusion, to obtain accurate analysis of the short-axis views for RV volume measurement, it would be helpful to incorporate information from additional images, such as the long-axis views, to assist in delineating this chamber's complex anatomy.

Right ventricular function evaluated by thermodilution method in patients with chronic pulmonary diseases

The right ventricular ejection fraction (RVEF) is an objective evaluation of the right ventricular systolic function. Recently a rapid-response thermister pulmonary artery catheter which measures RVEF and stroke volume (SV) was introduced. With this new method, RVEF and the right ventricular volumes (RVV) were measured in patients with chronic pulmonary diseases (CPD) and normal subjects. In addition, to evaluate the validity of this method, the data was compared with Kr81m perfusion method. The RVEF and the RVV of CPD patients were also compared with pulmonary hemodynamic data. There was a good correlation between the RVEFs obtained by the Kr81m perfusion method and the TD method. (r = 0.71, p less than 0.001). There was a tendency towards a low RVEF in patient with CPD with pulmonary hypertension (PAm greater than 20 mmHg) or high pulmonary vascular resistance (PAR greater than 160 dyne/sec/cm-5) and the RVV increased in the same group. These results suggested that the right ventricle was unable to respond to the increase of afterload in the CPD group and the evaluation of RVEF and RVV in patients with CPD using the new TD method was valuable for assessing the right ventricular function.

Continuous Positive Airway Pressure Therapy Reduces Right Ventricular Volume in Patients with Obstructive Sleep Apnea: A Cardiovascular Magnetic Resonance Study

There are few data on the effects of continuous positive airway pressure (CPAP) therapy on the structural and functional characteristics of the right heart in patients with obstructive sleep apnea (OSA). We sought to leverage the advantages of cardiac magnetic resonance imaging (CMR) and hypothesized that CPAP treatment would improve right ventricular (RV) function in a group of patients with OSA who were free of other comorbid conditions. Patients with severe (apnea-hypopnea index > or = 30/h) untreated OSAwere prospectively enrolled. CMR included 3-dimensional measurement of biventricular size and function, and rest/stress myocardial perfusion and was performed at baseline and after 3 months of CPAP therapy. Fifteen patients with mild to moderate desaturation were enrolled; 2 could not undergo CMR due to claustrophobia and obesity. There were significant decreases in the Epworth Sleepiness Scale score (p < 0.0001) and RV end-systolic and RV end-diastolic volumes (p < 0.05) with CPAP. There was a trend toward improvement in RV ejection fraction, but the improvement did not reach statistical significance. Other measures such as left ventricular volumes, left ventricular ejection fraction, myocardial perfusion reserve index, and thickness of the interventricular septum and ventricular free wall did not change significantly. This preliminary study found that CPAP treatment decreases RV volumes in patients with severe OSA who are otherwise healthy. CMR offers a novel technique to determine the effects of CPAP on ventricular structure and function in patients with OSA. A randomized controlled study is needed to confirm the results of our study.

Assessment of biventricular functional reserve and NT-proBNP levels in patients with RV volume overload after repair of tetralogy of Fallot at young age

Purpose To assess biventricular functional reserve (FR), NT-proBNP levels and exercise performance, in relation to right ventricular volume in patients with pulmonary regurgitation (PR) after repair of tetralogy of Fallot (TOF) at young age. Methods In 53 TOF patients (maximum age at repair 2.0 years, interval since repair 15 (5) years) without residual lesions except PR, biventricular FR (derived from magnetic resonance imaging with dobutamine stress), NT-proBNP levels, maximal workload, and peak oxygen uptake were assessed. Results Mean right ventricular end-diastolic volume was 140(38) ml/m 2. Median pulmonary regurgitant fraction was 37% (range 0–57%). Biventricular systolic stress response was normal: mean (SD) ESV decreased (ΔRVESV − 17(8) ml/m 2, ΔLVESV − 11(5)), SV increased (ΔRVSV + 12(9) ml/m 2, ΔLVSV + 9(6)), FR was positive in all (RV-FR + 11(5)%, LV-FR + 13(6)). No serious adverse effects to dobutamine were encountered. NT-proBNP was increased in 2 patients. Median level was 10 pmol/L (range 2–42). NT-proBNP correlated with PR-percentage but not with right ventricular size. High-risk levels of NT-proBNP indicated a smaller RV-FR and a smaller decrease of biventricular ESV. Mean (SEM) VO2 max was 96(3)%, mean Workload max 89(2)% of predicted. Conclusion At mid to long term follow-up overall NT-proBNP levels are normal and biventricular functional reserve and exercise tolerance are well preserved in TOF repaired at young age, irrespective of RV volume. This questions the validity of isolated PR or RV volume criteria for pulmonary valve replacement in this group. Low-dose dobutamine stress testing is well tolerated and may be a useful additional tool for clinical decision making.

Accuracy of guideline recommendations for two-dimensional quantification of the right ventricle by echocardiography

The accuracy of the guidelines of the American Society of Echocardiography (ASE) for the two-dimensional (2D) quantitative assessment of right ventricular (RV) size and function has not been evaluated against MRI-derived RV volumes in patients with congenital heart disease and RV volume overload. Three groups of patients were studied: a normal RV group (Group I, n = 31), a repaired tetralogy of Fallot group (Group II, n = 33), and an unrepaired atrial septal defect and/or partially anomalous pulmonary venous connection group (Group III, n = 23). Recommended 2D linear and cross-sectional area measurements were made on clinical echocardiographic and MRI studies performed less than 6 months apart. Most 2D RV parameters were smaller by echocardiography versus MRI. There was weak correlation between 2D RV measurements by echocardiography and MRI-derived RV volumes (Group I: r = 0.15-0.54, Group II: r = 0.33-0.61, Group III: r = 0.32-0.85), and only modest improvement when the same 2D measurements were performed by MRI (Group I: r = 0.37-0.61, Group II: r = 0.44-0.69, Group III: r = 0.28-0.74). The difference between 2D RV measurements by echocardiography and MRI-derived RV volumes was more pronounced in the RV volume overload groups. The correlation between currently recommended 2D RV measurements by echocardiography and MRI-derived RV volumes was weak, and improved only modestly when MRI was used to make the same 2D measurements. Moreover, 2D echocardiographic assessment of the RV appears to be less accurate in patients with congenital heart disease and a dilated RV.

Right heart overload contributes to cardiac natriuretic hormone elevation in patients with heart failure

Background Atrial and brain natriuretic peptides (ANP and BNP) plasma concentration increases and holds a prognostic significance in patients with left ventricular dysfunction. We assessed the hypothesis that right ventricular (RV) overload might significantly contribute to plasma elevation of cardiac natriuretic hormones in patients with heart failure. Methods Forty-one patients with cardiomyopathy and depressed left ventricular (LV) function (ejection fraction, EF, <40%), underwent cardiac magnetic resonance imaging (MRI) and resting plasma determination of ANP and BNP. Nineteen healthy subjects were also studied as control group. Ventricular volumes and function were assessed by MRI. Results In the group of patients, LVEF was 22.6±1.2% (controls: 61.2±1.3%, P<0.001, mean±S.E.M.), while RVEF was 48.2±2.5% (controls: 66.7±1.6%, P<0.001); LV and RV end diastolic/systolic volumes, corrected by body surface area, were 143±7/114±7 ml/m 2 (controls 70±3/27±2 ml/m 2, both P<0.001) and 66±3/37±4 ml/m 2 (controls: 63±4/21±2 ml/m 2, P<0.01 only for end-systolic volume). BNP plasma value was on average 324±39 pg/ml (range: 23–1280, controls 10±2 pg/ml), ANP value was 144±17 pg/ml (range: 26–534, controls 15±1 pg/ml). BNP positively correlated with either end-diastolic or end-systolic RV volume in patients, less with LV systolic, and not with LV diastolic volume. Moreover, a significant negative correlation was observed between BNP and either LVEF or RVEF. Conversely, ANP showed a significant correlation only with end-systolic RV volume and with both RVEF and LVEF. When multivariate stepwise linear regression analysis was applied LVEF resulted the only independent predictor for ANP plasma values ( R=0.591, P<0.001), while LVEF and RV end-diastolic volume for BNP ( R=0.881, P<0.001, and R=0.881, P=0.035, respectively). Conclusions Right heart overload contributes independently to plasma elevation of natriuretic peptides. RV involvement, which is known to independently worsen prognosis in patients with cardiomyopathy, might contribute to their established prognostic power, inducing compensatory secretion of plasma cardiac natriuretic hormones.

Evaluation of Right Ventricular Performance With a Right Ventricular Ejection Fraction Thermodilution Catheter and MRI in Patients With Pulmonary Hypertension

We sought to compare catheter studies using a right ventricular ejection fraction (REF) catheter together with echocardiography and MRI in patients with pulmonary hypertension. We compared hemodynamic findings, echocardiography, and MRI studies in 16 patients with pulmonary hypertension. Six healthy volunteers served as control subjects for the MRI studies. MRI imaging provided accurate assessment of cardiac output in all but two patients. As compared with MRI, the REF catheter constantly underestimated the REF and overestimated right ventricular volumes in patients with pulmonary hypertension. REF, end-systolic and end-diastolic right ventricular volumes, and right ventricular muscle mass, as determined by MRI, were almost identical in patients with preserved cardiac function and those with low-output failure. The only factor that was different in both groups was the severity of tricuspid regurgitation. Right ventricular dimensions and muscle mass do not differ in patients with pulmonary hypertension who have low cardiac output and those who do not. According to our results, the major determinant of cardiac output in these patients appears to be the severity of tricuspid regurgitation. The REF catheter provides invalid data on right ventricular dimensions in patients with pulmonary hypertension.

Reproducibility of right and left ventricular volume measurements by electron-beam CT in patients with congestive heart failure.

The applicability and reproducibility of electron-beam computed tomography (EBCT) was tested to define left and right ventricular volumes in patients with congestive heart failure in a clinical setting. Ten patients (mean age 64 +/- 11 years) with dilated hearts and stable congestive heart failure (functional class III-IV) were studied. After determination of the individual circulation time, two serial short axis polytomographic EBCT studies were performed within a mean interval of 14.8 +/- 10 days. Following intravenous contrast administration, biventricular end-diastolic volumes (LVEDV, RVEDV), end-systolic volumes (LVESV, RVESV), and left ventricular muscle mass (LVMM) were determined using previously developed techniques. Adequate contrast opacification in both ventricular cavities was obtained in all patients at baseline and at follow-up. Values were 323.4 +/- 99.3 (mean +/- SD) and 332.6 +/- 105.4 ml for LVEDV, 249.3 +/- 75.6 and 250.5 +/- 79.3 ml for LVESV, 236.8 +/- 56.2 and 251.2 +/- 72.7 ml for RVEDV, 179.8 +/- 76.4 and 188.3 +/- 64.0 ml for RVESV, and 207.7 +/- 70.6 and 204.9 +/- 81.9 g for LVMM (p = NS, respectively, paired t-test). Linear regression analysis correlating biventricular volumes and left ventricular muscle mass measurements in the serial scans yielded r-values in the range of 0.89 to 0.95 and a small SEE. The SE of the mean differences between left and right ventricular ejection fraction measurements was 1 point, respectively. EBCT studies of ventricular volumes in patients with dilated hearts and congestive heart failure are highly reproducible and offer the potential for serial assessment of these patients in whom quantitation of ventricular volumes has been shown to be of prognostic value.

Magnetic resonance imaging for quantitation of right ventricular volume in patients with pulmonary hypertension.

Evaluation of right ventricular function in patients with right-sided heart failure is difficult because of the complex anatomy of the right ventricle; the distinct geometry of the dilating, failing right ventricle; its variance from the typical oblate spheroid shape used to model the left ventricle; associated cardiac lesions in patients with right ventricular failure (including tricuspid and pulmonary regurgitation); and the inherent risk of conventional contrast ventriculography. With magnetic resonance techniques, tomographic images of the heart may be obtained at multiple points in the cardiac cycle without the use of intravascular contrast agents. From the end-diastolic and end-systolic images, chamber volume may then be determined directly without any modeling assumptions as to the geometry of the ventricular chamber.