Perioperative Fluid Management and Volume Assessment.

Fluid therapy is an integral component of perioperative care and helps maintain or restore effective circulating blood volume. The principal goal of fluid management is to optimize cardiac preload, maximize stroke volume, and maintain adequate organ perfusion. Accurate assessment of volume status and volume responsiveness is necessary for appropriate and judicious utilization of fluid therapy. To accomplish this, static and dynamic indicators of fluid responsiveness have been widely studied. This review discusses the overarching goals of perioperative fluid management, reviews the physiology and parameters used to assess fluid responsiveness, and provides evidence-based recommendations on intraoperative fluid management.

Small Cavity of Left Ventricle Does Not Affect Short-term Outcome in Patients with Rheumatic Mitral Valve Stenosis Undergoing Mitral Valve Replacement.

BACKGROUND: Small cavity left ventricle (SCLV) may affect the clinical outcomes of patients undergoing mitral valve replacement (MVR). This study aims to investigate the incidence of SCLV in patients with rheumatic mitral valve stenosis undergoing MVR and analyze its effect on short-term patient outcomes. METHODS: We retrospectively examined all consecutive patients with isolated or concomitant MVR for rheumatic mitral valve stenosis in our center from 2013 to 2018. SCLV was defined as end-diastolic volume index ≤ 50 ml/m2. After inclusion and exclusion, a total of 1,437 patients were analyzed. The baseline information was collected and compared between SCLV and non-SCLV patients. Multivariate logistic regression analysis was conducted to determine the effect of SCLV on early mortality. RESULTS: A total of 1,437 patients were included in the study. SCLV was detected in 13.57% of the patients. Compared with the non-SCLV group, patients with SCLV were smaller-sized and primarily female. There were no significant differences between SCLV and non-SCLV patients regarding major postoperative complications, nor were there incidence of prosthesis-patient mismatch. Logistic regression analysis showed that SCLV was not a risk factor for short-term mortality (P = 0.998). CONCLUSIONS: Our results demonstrated that SCLV was not associated with poorer early outcomes after MVR surgery in patients with rheumatic mitral valve stenosis.

Evaluation of left ventricular volumes and ejection fraction by 99mTc-MIBI gated SPECT and 18F-FDG gated PET in patients with prior myocardial infarction.

BACKGROUND: This study aimed to compare the accuracy of gated-SPECT (GSPECT) and gated-PET (GPET) in the assessment of left ventricular (LV) end-diastolic volumes (EDVs), end-systolic volumes (ESVs) and LV ejection fractions (LVEFs) among patients with prior myocardial infarction (MI). METHODS: One hundred and sixty-eight consecutive patients with MI who underwent GSPECT and GPET were included. Of them, 76 patients underwent CMR in addition to the two imaging modalities. The measurements of LV volumes and LVEF were performed using Quantitative Gated SPECT (QGS), Emory Cardiac Toolbox (ECTB), and 4D-MSPECT (4DM). RESULTS: The correlation between GPET, GSPECT, and CMR were excellent for LV EDV (r = 0.855 to 0.914), ESV (r = 0.852 to 0.949), and LVEF (r = 0.618 to 0.820), as calculated from QGS, ECTB, and 4DM. In addition, subgroup analysis revealed that EDV, ESV, and LVEF measured by GPET were accurate in patients with different extents of total perfusion defect (TPD), viable myocardium, and perfusion/metabolic mismatch. Furthermore, multivariate regression analysis identified that mismatch score was associated with the difference in EDV (P < 0.05) measurements between GPET and CMR. CONCLUSIONS: In patients with MI, LV volumes and LVEF scores measured by both GSPECT and GPET imaging were comparable to those determined by CMR, but should not be interchangeable in individual patients.

Re-visiting the Frank-Starling nexus.

Well over a century ago, Otto Frank, working at Carl Ludwig's Institute of Physiology in Munich, studying the isolated, blood-perfused, frog heart preparation, demonstrated that there are two distinct pressure-volume relations in the heart: one for isovolumic twitches and a second (located inferiorly) for afterloaded twitches. Whereas Starling, working at UCL two decades later, referenced Frank's publication (to the extent of re-printing its seminal Figure), he appeared not to have tested Frank's finding. Hence, he remained silent with respect to Franks' contention that cardiac pressure-volume relations are contraction-mode-dependent. Instead, he concluded that "The energy of contraction, however measured, is a function of the length of the muscle fibre" - a conclusion that has become known (at least in the English-speaking world) as 'Starling's Law of the Heart'. This provides us with at least three conundra: (i) why did Starling present only one pressure-volume relation whereas Frank had previously found two, (ii) why, then, do we speak of The Frank-Starling relation, and (iii) how did Frank become largely forgotten for twelve decades among English speakers? This review will attempt to address and comment on these conundra.

A novel method of donor‒recipient size matching in pediatric heart transplantation: A total cardiac volume‒predictive model.

BACKGROUND: The pediatric heart transplant community uses weight-based donor-to-recipient size matching almost exclusively, despite no evidence to validate weight as a reliable surrogate of cardiac size. Donor size mismatch is the second most common reason for the refusal of donor hearts in current practice (∼30% of all refusals). Whereas case-by-case segmentation of total cardiac volume (TCV) by computed tomography (CT) for direct virtual transplantation is an attractive option, it remains limited by the unavailability of donor chest CT. We sought to establish a predictive model for donor TCV on the basis of anthropomorphic and chest X-ray (CXR) cardiac measures. METHODS: Banked imaging studies from 141 subjects with normal CT chest angiograms were obtained and segmented using 3-dimensional modeling to derive TCV. CXR data were available for 62 of those subjects. A total of 3 predictive models of TCV were fit through multiple linear regression using the following variables: Model A (weight only); Model B (weight, height, sex, and age); Model C (weight, height, sex, age, and 1-view anteroposterior CXR maximal horizontal cardiac width). RESULTS: Model C provided the most accurate prediction of TCV (optimism corrected R2 = 0.99, testing set R2 = 0.98, mean absolute percentage error [MAPE] = 8.6%) and outperformed Model A (optimism corrected R2 = 0.94, testing set R2 = 0.94, MAPE = 16.1%) and Model B (optimism corrected R2 = 0.97, testing set R2 = 0.97, MAPE = 11.1%). CONCLUSIONS: TCV can be predicted accurately using readily available anthropometrics and a 1-view CXR from donor candidates. This simple and scalable method of TCV estimation may provide a reliable and consistent method to improve donor size matching.

Predicting Left Atrial Appendage Thrombus from Left Atrial Volume and Confirmation by Computed Tomography with Delayed Enhancement.

Assessing thromboembolic risk is crucial for proper management of patients with atrial fibrillation. Left atrial volume is a promising predictor of cardiac thrombosis. To determine whether left atrial volume can predict left atrial appendage thrombus in patients with atrial fibrillation, we conducted a prospective study of 73 patients. Left atrial and ventricular volumes were evaluated by cardiac computed tomography with retrospective electrocardiographic gating and then indexed to body surface area. Left atrial appendage thrombus was confirmed or excluded by cardiac computed tomography with delayed enhancement. Seven patients (9.6%) had left atrial appendage thrombus; 66 (90.4%) did not. Those with thrombus had a significantly higher mean left atrial end-systolic volume index (139 ± 55 vs 101 ± 35 mL/m2; P =0.0097) and mean left atrial end-diastolic volume index (122 ± 45 vs 84 ± 34 mL/m2; P =0.0077). On multivariate logistic regression analysis, left atrial end-systolic volume index (per 10 mL/m2 increase) was significantly associated with left atrial appendage thrombus (odds ratio [OR]=1.24; 95% CI, 1.03-1.50; P =0.02); so too was the left atrial end-diastolic volume index (per 10 mL/m2 increase) (OR=1.29; 95% CI, 1.05-1.60; P =0.02). These findings suggest that increased left atrial volume increases the risk of left atrial appendage thrombus. Therefore, patients with atrial fibrillation and an enlarged left atrium should be considered for cardiac computed tomography with delayed enhancement to confirm whether thrombus is present.

Prevention of sudden cardiac death in hypertrophic cardiomyopathy: Risk assessment using left atrial diameter predicted from left atrial volume.

BACKGROUND: Left atrial diameter (LAd) is included in the European Society for Cardiology's (ESC) risk model for assessment of sudden cardiac death (SCD) risk in hypertrophic cardiomyopathy (HCM), but the recommended measure of LA size is left atrial volume (LAv). HYPOTHESIS: We hypothesized that LAv could be used instead of LAd in the HCM risk-SCD model. We aimed to determine the relation between LAd and LAv and to assess the impact of using LAv instead of LAd. METHODS: Echocardiographic measurements of anteroposterior LAd in the parasternal long-axis window and LAv from Simpson's biplane method of disks were used. The 5-year risk of SCD by measured LAd and by LAd predicted from LAv were estimated using the ESC risk-SCD model. RESULTS: In 205 HCM patients (age 56 ± 14 years, 62% male), the relation between LAd and LAv was linear. Median 5-year risk of SCD was 2.4% (interquartile range [IQR]: 1.6; 3.8) using measured LAd and 2.4% (IQR: 1.6; 3.7) using predicted LAd. The correlation between the SCD risk assessed by measured vs predicted LAd was excellent (r2 = 0.96). Use of predicted LAd resulted in four patients (2%) being recategorized between the moderate and high-risk categories. CONCLUSIONS: The relation between LAd and LAv was linear with good agreement. On a population level, the correlation between the risk of SCD using measured LAd or LAd predicted from LAv was excellent. On a patient level, using LAd predicted from LAv resulted in the vast majority remaining in the same risk category; however, for a minority of patients, it changed the recommendation.

Commercial 4-dimensional echocardiography for murine heart volumetric evaluation after myocardial infarction.

BACKGROUND: Traditional preclinical echocardiography (ECHO) modalities, including 1-dimensional motion-mode (M-Mode) and 2-dimensional long axis (2D-US), rely on geometric and temporal assumptions about the heart for volumetric measurements. Surgical animal models, such as the mouse coronary artery ligation (CAL) model of myocardial infarction, result in morphologic changes that do not fit these geometric assumptions. New ECHO technology, including 4-dimensional ultrasound (4D-US), improves on these traditional models. This paper aims to compare commercially available 4D-US to M-mode and 2D-US in a mouse model of CAL. METHODS: 37 mice underwent CAL surgery, of which 32 survived to a 4 week post-operative time point. ECHO was completed at baseline, 1 week, and 4 weeks after CAL. M-mode, 2D-US, and 4D-US were taken at each time point and evaluated by two separate echocardiographers. At 4 weeks, a subset (n = 12) of mice underwent cardiac magnetic resonance (CMR) imaging to serve as a reference standard. End systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) were compared among imaging modalities. Hearts were also collected for histologic evaluation of scar size (n = 16) and compared to ECHO-derived wall motion severity index (WMSI) and global longitudinal strain as well as gadolinium-enhanced CMR to compare scar assessment modalities. RESULTS: 4D-US provides close agreement of ESV (Bias: -2.55%, LOA: - 61.55 to 66.66) and EF (US Bias: 11.23%, LOA - 43.10 to 102.8) 4 weeks after CAL when compared to CMR, outperforming 2D-US and M-mode estimations. 4D-US has lower inter-user variability as measured by intraclass correlation (ICC) in the evaluation of EDV (0.91) and ESV (0.93) when compared to other modalities. 4D-US also allows for rapid assessment of WMSI, which correlates strongly with infarct size by histology (r = 0.77). CONCLUSION: 4D-US outperforms M-Mode and 2D-US for volumetric analysis 4 weeks after CAL and has higher inter-user reliability. 4D-US allows for rapid calculation of WMSI, which correlates well with histologic scar size.

Reproducibility of LVEF, LV volumes, and LV mass between Rubidium-82 PET/CT scans in young healthy volunteers using two commercially available software packages.

BACKGROUND: Global functional parameters are available from electrocardiographic gated Rubidium-82 positron emission tomography/computed tomography (82Rb-PET/CT). However, the reproducibility of these data is not clarified. We aimed to investigate reproducibility of left ventricular ejection fraction (LVEF), endsystolic volume (ESV), enddiastolic volume (EDV), and left ventricular (LV) mass between two scans and between two commercially available software packages. METHODS AND RESULTS: Forty healthy young volunteers underwent two 82Rb-PET/CT rest and adenosine stress scans obtaining global functional parameters. Corridor4DM (4DM) and Quantitative Gated SPECT (QGS) were used for analyses. Mean (± SD) age was 24 ± 4 years and 50% were men. High reproducibility of all parameters was found between scans and this was true for both software packages. LVEF at rest with 4DM: mean difference (95% CI) - 1.1 (- 3.0 to 0.8), P = .25, limits of agreement: - 12.8 to 10.6. Significant differences were found between software packages on all functional parameters (P < .0001). CONCLUSION: High reproducibility was found between scans when measuring LVEF, ESV, EDV, and LV mass from 82Rb-PET/CT. However, concordance between parameter measures was poor when comparing the two software packages. Thus, global functional parameter measures are reliable, but the same software package should be used within a study and when comparing absolute values.

Accuracy of right ventricular volume and function assessed with cardiovascular magnetic resonance: comparison with echocardiographic parameters.

BACKGROUND: Cardiac magnetic resonance imaging (MRI) is an essential imaging method used to assess patients with diseases of the left and right ventricles. Cardiac MRI is the gold standard for right ventricular measurements; however, the most suitable method for volumetric analysis of the right ventricle remains controversial. AIMS: To compare the accuracy of the short axis and four-chamber view segmentation methods in assessing the right ventricle in cardiac MRI studies, to determine the reproducibility of cardiac MR measurements, and to correlate cardiac MR methods with frequently used echocardiographic methods. METHODS: Eighty patients with different clinical indications were studied using a 1.5-Tesla resonance magnetic unit. In all patients, the end-diastolic volume, end-systolic volume, and right ventricle ejection fraction were measured in the short axis and four-chamber views. Twenty-three patients also underwent echocardiography on the same day the cardiac MRI was completed. RESULTS: Cardiac MRI revealed no statistically significant differences in the volume or function of the right ventricle, calculated by the two segmentation methods (p > 0.05). The correlation was excellent between both planes in the assessment of the volume (concordance correlation coefficient [CCC] = 0.97) and the ejection fraction (CCC = 0.90). The correlation was low between the right ventricular ejection fraction and the echocardiographic methods (CCC = 0.02 and CCC = 0.01). CONCLUSION: Right ventricular function in normal ventricles and in dilated ventricles was appropriately measured by cardiac MRI using either of the two segmentation methods. Both methods were highly accurate. However, the correlation with echocardiographic methods was rather poor.

Tricuspid annular plane systolic excursion is dependent on right ventricular volume in addition to function.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE) is an effective parameter for assessing right ventricular (RV) function in echocardiographic studies. The preload dependency of TASPE has not been explored. METHODS: We retrospectively reviewed 380 cardiac magnetic resonance (CMR) exams. RV ejection fraction (EF) and end-diastolic volume (EDV) were measured from short-axis cine images. TAPSE was measured as the difference of the perpendicular distance of the tricuspid annulus to the RV apex during diastole and systole. RV dysfunction was defined as RVEF <47%. The relationship of TAPSE, RVEF, and indexed RVEDV (RVEDVi) were evaluated. The TAPSE cut-off values derived from CMR were tested in a validation group (n = 46) with an echocardiographic exam performed within 1 month of the CMR. RESULTS: TAPSE had a good linear correlation with RVEF (r = .69, P < .001). In normal RVEF patients, TAPSE had a positive correlation with RVEDVi (r = .208, P = .014). Receiver operating characteristic analysis revealed a higher TAPSE cut-off value of 2.4 cm in the top normal to mildly dilated RV volume group for identifying RV dysfunction with lower predictive accuracy (sensitivity 80%, specificity 67%, area under the curve = 0.78, P < .001) as compared with 2.0 cm for the normal RV size or moderate to severely dilated RV groups. The higher TAPSE cutoff showed improved sensitivity (73% vs 43%) and Youden index (0.55 vs 0.43) in our validation cohort. CONCLUSIONS: Tricuspid annular plane systolic excursion not only correlates with RVEF, but also is dependent on RV volume. The cut-off value and predictive accuracy of TAPSE for detecting RV dysfunction vary with different RV volumes.

Exercise Rehabilitation Improves Cardiac Volumes and Functional Capacity in Patients With Endomyocardial Fibrosis: A RANDOMIZED CONTROLLED TRIAL.

PURPOSE: Endomyocardial fibrosis (EMF) is a restrictive cardiomyopathy associated with low functional capacity and high mortality rates. Exercise training has been proved to be a nonpharmacological treatment of cardiovascular diseases. Therefore, the purpose of this study was to determine the effects of exercise rehabilitation in EMF patients. METHODS: Twenty-two EMF patients, functional classes II and III (New York Heart Association [NYHA]), were randomized to the control (C-EMF) or exercise rehabilitation (Rehab-EMF) group. Patients in the Rehab-EMF group underwent 4 mo of exercise rehabilitation, whereas patients in the C-EMF group were instructed to maintain their usual daily routine. Peak oxygen uptake ((Equation is included in full-text article.)O2), cardiac function, and quality of life were evaluated. All assessments were performed at baseline and after 4 mo. RESULTS: After 4 mo of rehabilitation, peak (Equation is included in full-text article.)O2 increased in the Rehab-EMF group (17.4 ± 3.0 to 19.7 ± 4.4 mL/kg/min, P < .001), whereas the C-EMF group showed no difference (15.3 ± 3.0 to 15.0 ± 2.0 mL/kg/min, P = .87). Also, post-intervention, peak (Equation is included in full-text article.)O2 in the Rehab-EMF group was greater than that in the C-EMF group (P < .001). Furthermore, the Rehab-EMF group, when compared to the C-EMF group, showed an increase in left ventricular end-diastolic volume (102.1 ± 64.6 to 136.2 ± 75.8 mL vs 114.4 ± 55.0 to 100.4 ± 49.9 mL, P < .001, respectively) and decrease in left atrial diastolic volume (69.0 ± 33.0 to 34.9 ± 15.0 mL vs 44.6 ± 21.0 to 45.6 ± 23.0 mL, P < .001, respectively). Quality-of-life scores also improved in the Rehab-EMF group, whereas the C-EMF group showed no change (45 ± 23 to 27 ± 15 vs 47 ± 15 to 45 ± 17, P < .001, respectively). CONCLUSION: Exercise rehabilitation is a nonpharmacological intervention that improves functional capacity, cardiac volumes, and quality of life in EMF patients after endocardial resection surgery. In addition, exercise rehabilitation should be prescribed to EMF patients to improve their clinical condition.

Usefulness of Right Ventricular Volumetric and Afterload Indices for Risk Stratification in Patients With Tetralogy of Fallot.

Right ventricular (RV) volume overload due to chronic pulmonary regurgitation is the common mechanism for hemodynamic deterioration after tetralogy of Fallot (TOF) repair. As a result, RV volumetric indices are used for clinical risk stratification in this population. Since RV afterload is a determinant of RV hemodynamic performance, we hypothesized that afterload-adjusted RV volumetric indices will have a better correlation with disease severity compared with RV volumetric indices alone in patients with TOF. Cross-sectional study of adults with previous TOF repair that received care at Mayo Clinic, 2002-2015. We defined disease severity as atrial arrhythmia and/or impaired exercise capacity. We created afterload-adjusted RV volumetric indices by indexing these indices to RV systolic pressure (RVSP) as follows: RV end-diastolic volume (RVEDVi)/RVSP, RV end-systolic volume (RVESVi)/RVSP, and RV ejection fraction (RVEF)/RVSP. The RV volumetric indices were: RVEDVi 141 ± 43 ml/m2, RVESVi 79 ± 38 ml/m2, and RVEF 44 ± 10%, and RVSP was 48 ± 9 mm Hg. RVESVi was the only RV volumetric parameter that was associated with disease severity (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.01 to 1.32, p = 0.041) with area under the curve (AUC) of 0.612. In contrast RVEF/RVSP (OR 0.73, 95% CI 0.38 to 0.92, p = 0.037, AUC 0.649), and RVESVi/RVSP (OR 1.28, 95% CI 1.14-1.55, p = 0.008, AUC 0.798) were associated with disease severity. Compared with RV volumetric indices alone, the combined RV volumetric and afterload indices had better correlation with disease severity as measured by AUC. Afterload-adjusted RV volumetric indices had better correlation with disease severity, and may potentially improve risk stratification in this population.

Cardiac Computed Tomography - More Than Coronary Arteries? A Clinical Update.

BACKGROUND: Rapid improvement of scanner and postprocessing technology as well as the introduction of minimally invasive procedures requiring preoperative imaging have led to the broad utilization of cardiac computed tomography (CT) beyond coronary CT angiography (CTA). METHOD: This review article presents an overview of recent literature on cardiac CT. The goal is to summarize the current guidelines on performing cardiac CT and to list established as well as emerging techniques with a special focus on extracoronary applications. RESULTS AND CONCLUSION: Most recent guidelines for the appropriate use of cardiac CT include the evaluation of coronary artery disease, cardiac morphology, intra- and extracardiac structures, and functional and structural assessment of the myocardium under certain conditions. Besides coronary CTA, novel applications such as the calculation of a CT-derived fractional flow reserve (CT-FFR), assessment of myocardial function and perfusion imaging, as well as pre-interventional planning in valvular heart disease or prior pulmonary vein ablation in atrial fibrillation are becoming increasingly important. Especially these extracoronary applications are of growing interest in the field of cardiac CT and are expected to be gradually implemented in the daily clinical routine. KEY POINTS: · Coronary artery imaging remains the main indication for cardiac CT. · Novel computational fluid dynamics allow the calculation of a CT-derived fractional flow reserve in patients with known or suspected coronary artery disease. · Cardiac CT delivers information on left ventricular volume as well as myocardial function and perfusion. · CT is the cardinal element for pre-interventional planning in transcatheter valve implantation and pulmonary vein isolation. CITATION FORMAT: · Taron J, Foldyna B, Eslami P et al. Cardiac Computed Tomography - More Than Coronary Arteries? A Clinical Update. Fortschr Röntgenstr 2019; 191: 817 - 826.

Quantification of interventricular dyssynchrony during continuous-flow left ventricular assist device support.

Under continuous-flow left ventricular assist device (CF-LVAD) support, the ventricular volume change and cardiac cycle between the left ventricle (LV) and right ventricle (RV) become dyssynchronous due to the shortening of the LV systole. The purpose of this study was to quantify interventricular dyssynchrony based on different CF-LVAD support conditions and assess its relationship with LV unloading. In this study, we evaluated seven goats (body weight 44.5 ± 6.5 kg) with normal hearts. A centrifugal LVAD was implanted under general anesthesia. We inserted the conductance catheters into the left ventricle (LV) and right ventricle (RV) to assess the volume signal simultaneously. We defined the interventricular dyssynchrony as a signal (increase or decrease) of LV volume (LVV) change opposite to that of RV volume (RVV) (i.e., (dLVV/dt) × (dRVV/dt) < 0). The duration of interventricular dyssynchrony (DYS) was reported as the percentage of time that a heart was in a dyssynchronous state within a cardiac cycle. The mean DYS of normal hearts, hearts with LVAD clamp and hearts supported by LVADs with a bypass rate of 50%, 75% and 100% were 5.6 ± 1.6%, 8.7 ± 2.4%, 8.6 ± 2.8%, 15.1 ± 5.1%, and 25.6 ± 8.0%, respectively. Furthermore, the DYS was found to be associated with the degree of LV stroke volume reduction caused by LV unloading. These findings may be useful for understanding interventricular interactions and physiology during CF-LVAD support. Influences on the right ventricular function and heart failure models warrant further study.

Assessment of the association between pre-treatment and post-treatment left atrium size and severity of disease in patients with acute pulmonary embolism by using computed tomography pulmonary angiography.

INTRODUCTION: As far as we know, left atrium (LA) imaging findings of pre-treatment and post-treatment nonmassive, submassive and massive acute pulmonary embolism (APE) have not been reported in literature. The aim of this study is to assess LA sizes of nonmassive, submassive and massive APE before and after treatment with computed tomography pulmonary angiography (CTPA) and to research whether there are differences between groups. MATERIALS AND METHODS: Sixty two adult APE patients (21 nonmassive, 31 submassive and 10 massive) who were diagnosed with CTPA and who had post-treatment follow-up images and recorded clinical information were included in the study. Pre-treatment and post-treatment LA sizes of all groups were measured by two radiologists independently. RESULT: The lowest pre-treatment LA size was found in massive APE and this difference was found to be statistically significant when compared with submassive (p= 0.001) and nonmassive (p< 0.001) groups. In addition, submassive APE patients were found to have lower LA size when compared with nonmassive APE patients (p= 0.006). In massive and submassive APE, post-treatment LA sizes were found to be statistically significantly higher when compared with pre-treatment (p< 0.001 for both groups). However, in nonmassive APE patients, pre-treatment and post-treatment LA size difference was not found to be statistically significant (p= 0.082). CONCLUSIONS: As the severity of APE increases, LA size decreases. Thus, a decrease LA size during APE can show increased APE severity. This study reported that LA size increased statistically in post-treatment massive and submassive APE patients when compared with pre-treatment. These results suggest that in APE patients, as a response to treatment, LA size can be an additional parameter reflecting the changes in cardiac morphology.

Relationship of Aortic Stiffness to Exercise and Ventricular Volumes in Single Ventricles.

BACKGROUND: Patients with single ventricle (SV) may often undergo aortic reconstruction that creates a stiff large vessel, increasing afterload and affecting exercise performance. The objective of this study was to determine the relationship of pulse wave velocity (PWV) and distensibility in reconstructed and normal aortic arches after Fontan with exercise variables. METHODS: PWV and distensibility of the descending aorta at the level of the diaphragm (DAo) were calculated with real-time exercise cardiac magnetic resonance in 48 patients with SV after Fontan (18 after aortic reconstruction; 30 without aortic reconstruction) and compared with metabolic exercise stress test variables. RESULTS: PWV was greater in the reconstructed group than in the non-reconstructed group (median 4.4 m/s [range: 2.3 to 9.8 m/s] versus 3.6 [range: 2.6 to 6.3 m/s], respectively, p = 0.003). Statistically significant inverse correlations were found between PWV and end-diastolic, end-systolic, and stroke volumes at rest and at exercise in the reconstructed group. In addition, inverse correlations also existed in the reconstructed group between distensibility of the DAo and the exercise variables such as peak oxygen pulse (R = 0.56, p = 0.02), peak oxygen consumption (R = 0.63, p = 0.008), oxygen consumption at ventilatory anaerobic threshold (R = 0.48, p = 0.04), and peak work (R = 0.54, p = 0.02). Similar correlations were not seen in patients with non-reconstructed aortas. CONCLUSIONS: Patients with SV with reconstructed aortas have increased aortic stiffness, increasing afterload on the ventricle. Native DAo stiffness distal to the reconstruction is inversely correlated with exercise performance, presumably to decrease impedance mismatch to maintain homogeneity of the aortic wall. This information suggests a possible mechanism for decreased exercise performance in patients with SV with aortic reconstructions.

Regional Right Ventricular Volume and Function Analysis Using Intraoperative 3-Dimensional Echocardiography-Derived Mesh Models.

OBJECTIVES: In daily echocardiographic practice, the right ventricle (RV) is assessed using mostly 2-dimensional (2D) echocardiography. Parameters measuring longitudinal shortening (eg, tricuspid annular plane systolic excursion) or changes in areas (eg, fractional area change) are used as surrogates for right ventricular function. Three-dimensional (3D) echocardiography-based techniques allow for cardiac magnetic resonance imaging-validated assessment of the RV. Depiction of regional right ventricular function is of increasing clinical interest. This study aimed to calculate regional volumetric changes in the right ventricular inlet, apical section, and outflow tract. Correlations between traditional parameters and regional right ventricular function were studied. DESIGN: Retrospective cohort study on patients scheduled for cardiac surgery. SETTING: Tertiary care university hospital. PARTICIPANTS: The study comprised 80 patients scheduled for cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Based on 3D echocardiographic datasets, mesh models of the RV were generated on a vendor-independent platform. The meshes were further cut into the following 3 regions: the inlet part, the apical section, and the outflow tract. The regional volumes and ejection fractions were compared with the global right ventricular and left ventricular functions. Regional volumes were correlated linearly with the global end-diastolic volume. The right ventricular outflow tract demonstrated a significantly lower ejection fraction than the inlet part (34% ± 11% v 28% ± 11%; p = 0.0054). The function in the right ventricular outflow tract was reduced significantly compared with the global right ventricular function in patients with severely reduced left ventricular ejection fraction (<20%). CONCLUSION: The different parts of the RV seem to have different ejection fractions. Different regions of the RV are affected differently by reduced left ventricular ejection fraction. Regional right ventricular analyses could help clinicians better understand pathologic states of the RV.