Proposal for a Display Method for Myocardial Single Photon Emission Computed Tomography Based on Left Ventricular Volume.

Bull's eye view for the display of myocardial single-photon emission computed tomography (SPECT) 3-D perfusion maps does not reflect left ventricular (LV) volume, an important parameter. We created and evaluated a myocardial SPECT display method that reflects the LV volume.Using Digital Imaging and Communications in Medicine data, short-axis slices from the apex to the base were reconstructed and interpolated into 0.5-mm thickness. We obtained the radial lengths at 1° intervals throughout 360°, and calculated the length of the LV long axis and half circumference (1/2 circ). Myocardial perfusion was displayed as 2 ellipsoidal developments that exhibited the left anterior descending coronary artery (LAD) and non-LAD regions. We created a system that can display these processes on a personal computer. Myocardial SPECT data from 526 individuals without heart disease were analyzed. The long axis and 1/2 circ were compared with the body size, LV end-diastolic diameter (LVDd) obtained by echocardiography, and the end-diastolic volume (EDV) obtained by electrocardiogram-gated SPECT analysis. The 1/2 circle correlated with the LVDd and EDV. The images obtained allowed a diagnosis comparable to that made using the conventional coordinate display system.The new myocardial display reflects ischemia and LV volume within a single image, which cannot be achieved with conventional SPECT image display. Additional studies of this display system are required to allow its application to patients with heart disease.

Reference Intervals of Fetal Cardiac Volume Between 14 and 40 Weeks of Gestation.

OBJECTIVES: To construct the reference intervals for the cardiac volume (CV) of normal fetuses between 14 and 40 weeks of pregnancy. METHODS: Low risk singleton pregnancies with normal fetuses were prospectively recruited to acquire 4D-cardio-spatiotemporal image correlation volume datasets (VDS). Subsequent off-line analyses of VDS were anonymously performed to calculate CV using the Virtual Organ Computer-aided AnaLysis technique. The reference intervals were established as a function of gestational age (GA), biparietal diameter (BPD), head circumference (HC), and estimated fetal weight (EFW) based on the best-fitted models for both mean and standard deviation (SD). RESULTS: A total of 668 VDS were successfully calculated for CV. The best-fitted models for the means and SDs are as follow: 1) GA in week = 6.422 + e(-100.653 × GA) (SD = 0.641 - (0.170 × GA) + (0.009 × GA2 )). 2) BPD = 0.016 × (BPD)3.589 (SD = 2.663 - (1.410 × BPD) + (0.224 × BPD2 )). 3) HC = 0.00017 × (HC)3.537 (SD = 2.341 - (0.341 × HC) + (0.015 × HC2 )). The CV progressively increased with advancing fetal age (GA) and size (BPD, HC). CONCLUSIONS: The reference intervals of CV, theoretically best representing cardiac size, in relation to GA, BPD, HC, and EFW were first established and Z-score was readily calculated. These will be helpful in detection of cardiac abnormalities, especially those associated with cardiomegaly.

Small whole heart volume predicts cardiovascular events in patients with stable chest pain: insights from the PROMISE trial.

OBJECTIVES: The size of the heart may predict major cardiovascular events (MACE) in patients with stable chest pain. We aimed to evaluate the prognostic value of 3D whole heart volume (WHV) derived from non-contrast cardiac computed tomography (CT). METHODS: Among participants randomized to the CT arm of the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE), we used deep learning to extract WHV, defined as the volume of the pericardial sac. We compared the WHV across categories of cardiovascular risk factors and coronary artery disease (CAD) characteristics and determined the association of WHV with MACE (all-cause death, myocardial infarction, unstable angina; median follow-up: 26 months). RESULTS: In the 3798 included patients (60.5 ± 8.2 years; 51.5% women), the WHV was 351.9 ± 57.6 cm3/m2. We found smaller WHV in no- or non-obstructive CAD, women, people with diabetes, sedentary lifestyle, and metabolic syndrome. Larger WHV was found in obstructive CAD, men, and increased atherosclerosis cardiovascular disease (ASCVD) risk score (p < 0.05). In a time-to-event analysis, small WHV was associated with over 4.4-fold risk of MACE (HR (per one standard deviation) = 0.221; 95% CI: 0.068-0.721; p = 0.012) independent of ASCVD risk score and CT-derived CAD characteristics. In patients with non-obstructive CAD, but not in those with no- or obstructive CAD, WHV increased the discriminatory capacity of ASCVD and CT-derived CAD characteristics significantly. CONCLUSIONS: Small WHV may represent a novel imaging marker of MACE in stable chest pain. In particular, WHV may improve risk stratification in patients with non-obstructive CAD, a cohort with an unmet need for better risk stratification. KEY POINTS: • Heart volume is easily assessable from non-contrast cardiac computed tomography. • Small heart volume may be an imaging marker of major adverse cardiac events independent and incremental to traditional cardiovascular risk factors and established CT measures of CAD. • Heart volume may improve cardiovascular risk stratification in patients with non-obstructive CAD.

Volumetrics and fit assessments for donor to recipient size matching in pediatric heart transplantation: Is it time for a new paradigm?

Pediatric heart transplant patients face the highest waitlist mortality in solid organ transplantation. Given the relatively fixed number of donor organs becoming available each year, improving donor organ utilization could potentially have significant impact on reducing waitlist mortality. Donor to recipient weight ratio has historically been used to identify suitable donors; however, this method does not take into account the potential for significant variance in heart size due to complex congenital heart disease or underlying cardiomyopathy. We believe, based on our experience to date, that donor matching based upon weight ratios should be augmented by improved methodologies that provide a more accurate assessment of heart volumes. Herein we describe the rationale for these methodologies and our single-center experience using volumetrics as an alternative for donor fit assessments.

Association Between Variation in Preoperative Care Before Arterial Switch Operation and Outcomes in Patients With Transposition of the Great Arteries.

BACKGROUND: The arterial switch operation (ASO) is the gold standard operative correction of neonates with transposition of the great arteries and intact ventricular septum, with excellent operative survival. The associations between patient and surgeon characteristics and outcomes are well understood, but the associations between variation in preoperative care and outcomes are less well studied. METHODS: A multicenter retrospective cohort study of infants undergoing neonatal ASO between January 2010 and September 2015 at hospitals contributing data to the Pediatric Health Information Systems database was performed. The association between preoperative care (timing of ASO, preoperative use of balloon atrial septostomy, prostaglandin infusion, mechanical ventilation, and vasoactive agents) and operative outcomes (mortality, length of stay, and cost) was studied with multivariable mixed-effects models. RESULTS: Over the study period, 2159 neonates at 40 hospitals were evaluated. Perioperative mortality was 2.8%. Between hospitals, the use of adjuvant therapies and timing of ASO varied broadly. At the subject level, older age at ASO was associated with higher mortality risk (age >6 days: odds ratio, 1.90; 95% CI, 1.11-3.26; P=0.02), cost, and length of stay. Receipt of a balloon atrial septostomy was associated with lower mortality risk (odds ratio, 0.32; 95% CI, 0.17-0.59; P<0.001), cost, and length of stay. Later hospital median age at ASO was associated with higher odds of mortality (odds ratio, 1.15 per day; 95% CI, 1.02-1.29; P=0.03), longer length of stay ( P<0.004), and higher cost ( P<0.001). Other hospital factors were not independently associated with the outcomes of interest. CONCLUSIONS: There was significant variation in preoperative care between hospitals. Some potentially modifiable aspects of perioperative care (timing of ASO and septostomy) were significantly associated with mortality, length of stay, and cost. Further research on the perioperative care of neonates is necessary to determine whether modifying practice on the basis of the observed associations translates into improved outcomes.

Effects of empagliflozin treatment on cardiac function and structure in patients with type 2 diabetes: a cardiac magnetic resonance study.

BACKGROUND: The effects of empagliflozin on cardiac structure and function are not known. AIMS: To examine the changes in cardiac structure and function following the addition of empagliflozin in patients with type 2 (T2D) diabetes using cardiac magnetic resonance (CMR) imaging. METHODS: Twenty patients attending a specialist diabetes service recommended for treatment with empagliflozin, and 8 control patients with T2D on stable glucose lowering therapy were recruited for cardiac imaging. Participants underwent CMR scans at baseline and 6 months. Inclusion criteria were established T2D, age < 75 years, estimated glomerular filtration rate ≥45 mL/min/1.73 m2 . RESULTS: 17 of 20 in the empagliflozin group, and all of 8 in the control group completed the study. Empagliflozin therapy was associated with reduction in left ventricular end diastolic volume 155 mL (137 mL, 174 mL) at baseline to 145 mL (125 mL, 165 mL) at 6 months, P < 0.01, compared with the control group 153 mL (128 mL, 179 mL) at baseline and 158 mL (128 mL, 190 mL), not significant. There were no differences in measures of left ventricular mass, ejection fraction, heart rate or markers of cardiac fibrosis at baseline and 6 months in either group. CONCLUSIONS: This is the first CMR study to examine the effects of empagliflozin on cardiac function and structure, showing evidence of reduced end diastolic volume. This is likely to reflect change in plasma volume, and may explain the reduced cardiovascular death and heart failure seen in the EMPA-REG OUTCOME trial.

Improved Workflow for Quantification of Right Ventricular Volumes Using Free-Breathing Motion Corrected Cine Imaging.

Cardiac MR traditionally requires breath-holding for cine imaging. Younger or less stable patients benefit from free-breathing during cardiac MR but current free-breathing cine images can be spatially blurred. Motion corrected re-binning (MOC) is a novel approach that acquires and then reformats real-time images over multiple cardiac cycles with high spatial resolution. The technique was previously limited by reconstruction time but distributed computing has reduced these times. Using this technique, left ventricular volumetry has compared favorably to breath-held balanced steady-state free precession cine imaging (BH), the current gold-standard, however, right ventricular volumetry validation remains incomplete, limiting the applicability of MOC in clinical practice. Fifty subjects underwent cardiac MR for evaluation of right ventricular size and function by end-diastolic (EDV) and end-systolic (ESV) volumetry. Measurements using MOC were compared to those using BH. Pearson correlation coefficients and Bland-Altman plots tested agreement across techniques. Total scan plus reconstruction times were tested for significant differences using paired t-test. Volumes obtained by MOC compared favorably to BH (R = 0.9911 for EDV, 0.9690 for ESV). Combined acquisition and reconstruction time (previously reported) were reduced 37% for MOC, requiring a mean of 5.2 min compared to 8.2 min for BH (p < 0.0001). Right ventricular volumetry compares favorably to BH using MOC image reconstruction, but is obtained in a fraction of the time. Combined with previous validation of its use for the left ventricle, this novel method now offers an alternative imaging approach in appropriate clinical settings.

Comparison of volumetric and functional parameters in simultaneous cardiac PET/MR: feasibility of volumetric assessment with residual activity from prior PET/CT.

OBJECTIVE: To compare cardiac left ventricular (LV) parameters in simultaneously acquired hybrid fluorine-18-fluorodeoxyglucose ([18F] FDG) positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with residual tracer activity of upstream PET/CT. METHODS: Twenty-nine patients (23 men, age 58±17 years) underwent cardiac PET/MRI either directly after a non-cardiac PET/CT with homogenous cardiac [18F] FDG uptake (n=20) or for viability assessment (n=9). Gated cardiac [18F] FDG PET and cine MR sequences were acquired simultaneously and evaluated blinded to the cross-imaging results. Image quality (IQ), end-diastolic (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF) and myocardial mass (LVMM) were measured. Pearson correlation and intraclass correlation coefficient (ICC), regression and a Bland-Altman analysis were assessed. RESULTS: Except LVMM, volumetric and functional LV parameters demonstrated high correlations (LVESV: r=0.97, LVEDV: r=0.95, LVEF: r=0.91, LVMM: r=0.87, each p<0.05), but wide limits of agreement (LOA) for LVEDV (-25.3-82.5ml); LVESV (-33.1-72.7ml); LVEF (-18.9-14.8%) and LVMM (-78.2-43.2g). Intra- and interobserver reliability were very high (ICC≥0.95) for all parameters, except for MR-LVEF (ICC=0.87). PET-IQ (0-3) was high (mean: 2.2±0.9) with significant influence on LVMM calculations only. CONCLUSION: In simultaneously acquired cardiac PET/MRI data, LVEDV, LVESV and LVEF show good agreement. However, the agreement seems to be limited if cardiac PET/MRI follows PET/CT and only the residual activity is used. KEY POINTS: • [ 18 F] FDG PET-MRI is feasible with residual [ 18 F] FDG activity in patients with homogenous cardiac uptake. • Cardiac volumes and function assessed by PET/MRI show good agreement. • LVEDV and LVESV are underestimated; PET overestimates LVMM and LVEF. • Cardiac PET and MRI data correlate better when acquired simultaneously than sequentially. • PET and MRI should not assess LV parameters interchangeably.

Assessment of Left Ventricular Function and Mass on Free-Breathing Compressed Sensing Real-Time Cine Imaging.

BACKGROUND: Compressed sensing (CS) cine magnetic resonance imaging (MRI) has the advantage of being inherently insensitive to respiratory motion. This study compared the accuracy of free-breathing (FB) CS and breath-hold (BH) standard cine MRI for left ventricular (LV) volume assessment.Methods and Results:Sixty-three patients underwent cine MRI with both techniques. Both types of images were acquired in stacks of 8 short-axis slices (temporal/spatial resolution, 41 ms/1.7×1.7×6 mm3) and compared for ejection fraction, end-diastolic and systolic volumes, stroke volume, and LV mass. Both BH standard and FB CS cine MRI provided acceptable image quality for LV volumetric analysis (score ≥3) in all patients (4.7±0.5 and 3.7±0.5, respectively; P<0.0001) and had good agreement on LV functional assessment. LV mass, however, was slightly underestimated on FB CS cine MRI (median, IQR: BH standard, 83.8 mL, 64.7-102.7 mL; FB CS, 79.0 mL, 66.0-101.0 mL; P=0.0006). The total acquisition times for BH standard and FB CS cine MRI were 113±7 s and 24±4 s, respectively (P<0.0001). CONCLUSIONS: Despite underestimation of LV mass, FB CS cine MRI is a clinically useful alternative to BH standard cine MRI in patients with impaired BH capacity.

Validity of automated measurement of left ventricular ejection fraction and volume using the Philips EPIQ system.

PURPOSE: To assess the efficiency and reproducibility of automated measurements of left ventricular (LV) volumes and LV ejection fraction (LVEF) in comparison to manually traced biplane Simpson's method. METHOD: This is a single-center prospective study. Apical four- and two-chamber views were acquired in patients in sinus rhythm. Two operators independently measured LV volumes and LVEF using biplane Simpson's method. In addition, the image analysis software a2DQ on the Philips EPIQ system was applied to automatically assess the LV volumes and LVEF. Time spent on each analysis, using both methods, was documented. Concordance of echocardiographic measures was evaluated using intraclass correlation (ICC) and Bland-Altman analysis. RESULTS: Manual tracing and automated measurement of LV volumes and LVEF were performed in 184 patients with a mean age of 67.3 ± 17.3 years and BMI 28.0 ± 6.8 kg/m2 . ICC and Bland-Altman analysis showed good agreements between manual and automated methods measuring LVEF, end-systolic, and end-diastolic volumes. The average analysis time was significantly less using the automated method than manual tracing (116 vs 217 seconds/patient, P < .0001). CONCLUSION: Automated measurement using the novel image analysis software a2DQ on the Philips EPIQ system produced accurate, efficient, and reproducible assessment of LV volumes and LVEF compared with manual measurement.

Effect of hydration status on atrial and ventricular volumes and function in healthy adult volunteers.

BACKGROUND: Assessment of cardiac chamber volumes is a fundamental part of cardiac magnetic resonance (CMR) imaging. While the effects of inter- and intraobserver variability have been studied and have a recognized effect on the comparability of serial cardiac MR imaging studies, the effect of differences in hydration status has not been evaluated. OBJECTIVE: To evaluate the effects of volume administration on cardiac chamber volumes. MATERIALS AND METHODS: Thirteen healthy adults underwent a baseline cardiac MR to evaluate cardiac chamber volumes after an overnight fast. They were then given two saline boluses of 10 ml/kg of body weight and the cardiac MR was repeated immediately after each bolus. RESULTS: From the baseline scan to the final scan there was a significant increase in all four cardiac chamber end-diastolic volumes. Right atrial volumes increased 8.0%, from 61.1 to 66.0 ml/m2 (P<0.001), and left atrial volumes increased 10.0%, from 50.0 to 55.0 ml/m2 (P<0.001). Right ventricular volumes increased 6.0%, from 91.1 to 96.5 ml/m2 (P<0.001), and left ventricular volumes increased 3.2%, from 87.0 to 89.8 ml/m2 (P<0.001). CONCLUSION: Hydration status has a significant effect on the end-diastolic volumes of all cardiac chambers assessed by cardiac MR. Thus, hydration represents a "variable" that should be taken into account when assessing cardiac chamber volumes, especially when performing serial imaging studies in a patient.

The potential overdose of heart and left anterior descending coronary artery region during intensity-modulated radiation therapy in patients with esophageal cancer.

This study aimed to investigate the changes in dose distribution in the heart and left anterior descending coronary artery region (LADR) during intensity-modulated radiation therapy (IMRT) in patients with esophageal cancer (EC) treated at our institution. The heart and LADR were delineated on the initial and off-cord boost planning computed tomography (CT) images. Cardiac volume reduction (CVR) was defined as the reduction in cardiac volume between the initial CT and off-cord boost CT at the dose of 36 Gy irradiated. The involved field IMRT plan was created based on each initial and off-cord boost CT image and was analyzed based on the relationship between CVR and heart and LADR dose-volume parameters (Heart-Dmax, Heart-Dmean, Heart-V20, Heart-V30, Heart-V40, LADR-Dmax, LADR-Dmean, LADR-V15 and LADR-V30). Forty patients with EC were investigated between January 2016 and January 2022. The median CVR ratio during radiation therapy (RT) was 5.57% (range, -7.79 to 18.26%). Simple linear regression analysis revealed significant correlations between CVR during RT and changes in the heart and LADR dose-volume parameters. Some patients (>10%) experienced severe changes in the heart and LADR dose distribution. In three cases with reduced heart volume and primary tumor mass, the changes in LADR-V15 and LADR-V30 showed outliers. In conclusion, CVR during RT correlated with an increase in the heart and LADR dose. When both CVR and tumor volume reduction are large, a potential overdose of LADR during RT should be noted in the IMRT era.

Echocardiography Provides a Reliable Estimate of Total Cardiac Volume for Pediatric Heart Transplantation.

BACKGROUND: Donor-to-recipient size matching for heart transplantation typically involves comparing donor and recipient body weight; however, weight is not linearly related to cardiac size. Attention has shifted toward the use of computed tomography- (CT-) derived total cardiac volume (TCV), that is, CT-TCV, to compare donor and recipient heart organ size. At this time, TCV size matching is near impossible for most centers due to logistical limitations. To overcome this impediment, echocardiogram-derived TCV (ECHO-TCV) is an attractive, alternative option to estimate CT-TCV. The goal of this study is to test whether ECHO-TCV is an accurate and reliable surrogate for TCV measurement compared with the gold standard CT-TCV. METHODS: ECHO-TCV and CT-TCV were measured in a cohort spanning the neonatal to young adult age range with the intention to simulate the pediatric heart transplant donor pool. ECHO-TCV was measured using a modified Simpson's summation-of-discs method from the apical 4-chamber (A4C) view. The gold standard of CT-TCV was measured from CT scans using three-dimensional reconstruction software. The relationship between ECHO-TCV and CT-TCV was evaluated and compared with other anthropometric and image-based markers that may predict CT-TCV. Inter-rater reliability of ECHO-TCV was tested among 4 independent observers. Subanalyses were performed to identify imaging views and timing that enable greater accuracy of ECHO-TCV. RESULTS: Banked imaging data of 136 subjects with both echocardiogram and CT were identified. ECHO-TCV demonstrated a linear relationship to CT-TCV with a Pearson correlation coefficient of r = 0.96 (95% CI, 0.95-0.97; P < .0001) and mean absolute percent error of 8.6%. ECHO-TCV correlated most strongly with CT-TCV in the subset of subjects <4 years of age (n = 33; r = 0.98; 95% CI, 0.96-0.99; P < .0001). The single-score intraclass correlation coefficient across all 4 raters is 0.96 (interquartile range, 0.93-0.98). ECHO-TCV measured from a standard A4C view at end diastole with the atria in the plane of view had the strongest correlation to CT-TCV. CONCLUSIONS: ECHO-TCV by the A4C view was found to be both an accurate and reliable alternative measurement of CT-TCV and is derived from readily available donor ECHO images. The ECHO-TCV findings in this study make the ECHO method an attractive means of direct donor-to-recipient TCV size matching in pediatric heart transplantation.

Impact of Size Matching on Survival Post Heart Transplant in Infants: Estimated Total Cardiac Volume Ratio Outperforms Donor-Recipient Weight Ratio.

PURPOSE: Cardiac volume-based estimation offers an alternative to donor-recipient weight ratio (DRWR) in pediatric heart transplantation (HT), but has not been correlated to post-transplant outcomes We sought to determine whether estimated Total Cardiac Volume (eTCV) ratio is associated with HT survival in infants. METHODS: The UNOS database was used to identify infants (age:<1year) who received HT in 1987-2020. Donor and recipient eTCV were calculated from weight using previously published data. Patient cohort was divided according to the significant range of eTCV ratio; characteristics and survival were compared. RESULTS: 2845 infants were identified. Hazard ratio with cubic spline showed prognostic relationship of eTCV ratio and DRWR with the overall survival. The cut-point method determined an optimal eTCV ratio range predictive of infant survival was 1.05-1.85 whereas no range for DRWR was predictive. 75.6% patients had an optimal TCV ratio, while 18.1% were in the lower (LR) and 6.3% in the higher (HR) group. Kaplan-Meier analysis showed better survival for patients within the optimal vs LR (p=0.0017), and a similar significantly better survival when compared to HR (p=0.0053). The optimal eTCV ratio group (n=2151) had DRWR ranging from 1.09-5; 34.3% had DRWR 2-3, and 5.0% DRWR>3. CONCLUSION: Currently, an upper DRWR limit has not been established in infants. Therefore, determining the optimal eTCV range is important to identifying an upper limit that significantly predicts survival benefit. This finding suggests a potential increase in donor pool for infant recipients since over 40% of donors in the optimal eTCV range includes DRWR values>2 that are traditionally not considered for candidate listing.

Investigation of the correlation between cardiac parameters and aortic diameter in patients with ascending aortic aneurysm.

BACKGROUND: Aortic aneurysms (AA) are enlargement of the aorta silently until diagnosing, not detectable on physical examination, and usually incidentally discovered during radiologic scanning for other reasons. It can get bigger sizes and can result in life-threatening outcomes if not detected early on. In this study, we aimed to determine the relationship between ascending aortic diameter and cardiac parameters that can be detected with tomography or/and echocardiography. Newly diagnosed (n: 85) ascending AA patients and healthy individuals (n: 86) who have not any thoracic pathology in computed tomography (CT) scans included to the study. Echocardiographically determined left atrial dimension (LAD), left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter (LVDs), left ventricular ejection fraction (LVEF) and the left ventricular posterior wall thickness (LVPWd) values of each patient were recorded. The thorax diameters, ascending aorta diameters and cardiac volume values recorded from CT scans. The obtained findings were statistically compared. RESULTS: Positive correlation was found between aortic diameter and aging (p: 0.000). Increased thorax diameter and cardiac volume values were detected in ascending AA cases (p < 0.05). It was found to be ascending aortic diameter was positively correlated with thorax diameter and cardiac volume (0.50 < r ≤ 0.70) values and higher aortic diameter, cardiac volume, thorax diameter values were detected in male individuals when compared with the female gender. There was no significant correlation between LVEF, LVDd, and LVDs values and aortic diameter. CONCLUSIONS: Cardiac volume and thorax diameter were found as strongly correlated with the diameter of the ascending aorta. The clarifying of these parameters with larger cohorts might be beneficial for the estimation of the progression of ascending AA.

Effects of vasopressin administration in the oral cavity on cardiac function and hemodynamics in rats.

BACKGROUND: The vasoconstrictive effect of epinephrine in local anesthetics affects the heart, which leads to hesitation among dentists in injecting local anesthetics into patients with cardiovascular disease. Due to its vasoconstrictive effects, the present study investigated the effects of vasopressin administration on cardiac function in rats. METHODS: Experiment 1 aimed to determine the vasopressin concentration that could affect cardiac function. An arterial catheter was inserted into the male Wistar rats. Next, 0.03, 0.3, and 3.0 U/mL arginine vasopressin (AVP) (0.03V, 0.3V, and 3.0V) was injected into the tongue, and the blood pressure was measured. The control group received normal saline only. In Experiment 2, following anesthesia infiltration, a pressure-volume catheter was placed in the left ventricle. Baseline values of end-systolic elastance, end-diastolic volume, end-systolic pressure, stroke work, stroke volume, and end-systolic elastance were recorded. Next, normal saline and 3.0V AVP were injected into the tongue to measure their effect on hemodynamic and cardiac function. RESULTS: After 3.0V administration, systolic blood pressures at 10 and 15 min were higher than those of the control group; they increased at 10 min compared with those at baseline. The diastolic blood pressures at 5-15 min were higher than those of the control group; they increased at 5 and 10 min compared with those at baseline. The preload decreased at 5 and 10 min compared to that at baseline. However, the afterload increased from 5 to 15 min compared with that of the control group; it increased at 10 min compared with that at baseline. Stroke volume decreased at 10 and 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Stroke work decreased from 5 to 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. CONCLUSION: Our results showed that 3.0 U/mL concentration of vasopressin resulted in increased blood pressure, decreased stroke volume and stoke work, decreased preload and increased afterload, without any effect on myocardial contractility.

Comparing donor and recipient total cardiac volume predicts risk of short-term adverse outcomes following heart transplantation.

INTRODUCTION: In pediatric heart transplantation, donor: recipient weight ratio (DRWR) has long been the sole metric for size matching. Total cardiac volume (TCV)-based size matching has emerged as a novel method to precisely identify an upper limit of donor organ size of a heart transplant recipient while minimizing the risk of complications from oversizing. The clinical adoption of donor: recipient volume ratio (DRVR) to prevent short-term adverse outcomes of oversizing is unknown. The purpose of this single-center study is to determine the relationship of DRWR and DRVR to the risk of post-operative complications from allograft oversizing. METHODS: Recipient TCV was measured from imaging studies and donor TCV was calculated from published TCV prediction models. DRVR was defined as donor TCV divided by recipient TCV. The primary outcome was short-term post-transplant complications (SPTC), a composite outcome of delayed chest closure and prolonged intubation > 7 days. A multivariable logistic regression model of DRWR (cubic spline), DRVR (linear) and linear interaction between DRWR and DRVR was used to examine the probability of experiencing a SPTC over follow-up as a function of DRWR and DRVR. RESULTS: A total of 106 transplant patients' records were reviewed. Risk of the SPTC increased as DRVR increased. Both low and high DRWR was associated with the SPTC. A logistic regression model including DRWR and DRVR predicted SPTC with an AUROC curve of 0.74. [95% CI 0.62 0.85]. The predictive model identified a "low-risk zone" of donor-recipient size match between a weight ratio of 0.8 and 2.0 and a TCV ratio less than 1.0. CONCLUSION: DRVR in combination with DRWR predicts short-term post-transplant adverse events. Accepting donors with high DRWR may be safely performed when DRVR is considered.

Clinical Significance of Partial Anomalous Pulmonary Venous Connections (Isolated and Atrial Septal Defect Associated) Determined by Cardiovascular Magnetic Resonance.

BACKGROUND: Partial anomalous venous connections (PAPVC) are associated with left to right shunting and right heart dilatation. Identification of PAPVC has increased with widespread use of cross-sectional imaging modalities. However, management strategies are mostly based on expert opinion given the scarcity of data from large series. We aimed to define types and significance of isolated and atrial septal defect (ASD) associated PAPVC detected by cardiovascular magnetic resonance. METHODS: We retrospectively reviewed our cardiovascular magnetic resonance database from 2002 to 2018 to identify isolated or ASD-associated PAPVC cases. RESULTS: A total of 215 patients (median age 46 years; range, 6-83) with isolated or ASD-associated PAPVC were identified among 102 135 clinical cardiovascular magnetic resonance studies. Of these, 104 were isolated and 111 were associated with an ASD. Anomalous connection of right upper pulmonary vein was the most common single venous anomaly (99/215), but in the isolated PAPVC group there were more anomalous left than right upper pulmonary veins (39 versus 34). The Qp/Qs was significantly higher for isolated anomalous single right upper pulmonary vein than left upper pulmonary vein (1.6 versus 1.4 respectively; P=0.01) as were right ventricular end-diastolic volumes (113.7±30.9 versus 90 [57-157] mL/m2, P=0.004). In the PAPVC with an ASD group, sinus venosus ASDs (82%) were associated with right-sided PAPVCs while both right and left-sided venous anomalies were seen in secundum ASDs (18%). In a substantial number of patients (30 out of 91) with sinus venosus ASDs, PAPVCs were more complex and involved more than a single anomalous right upper pulmonary vein; and in 5 patients with ASD, PAPVC was identified only after the ASD closure. CONCLUSIONS: This large series provides descriptive and hemodynamic features for isolated and ASD-associated PAPVCs. Anomalous isolated right upper pulmonary vein may cause a significant shunt (Qp/Qs >1.5). PAPVC associated with sinus venosus and secundum ASDs might be more complex than a single anomalous pulmonary vein and missed before ASD correction.

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.

Performance of Fetal Cardiac Volume Derived from VOCAL (Virtual Organ Computer-Aided AnaLysis) in Predicting Hemoglobin (Hb) Bart's Disease.

OBJECTIVE: To determine the performance of fetal cardiac volume (CV) in the detection of fetal Hb Bart's disease among fetuses at risk at 18-22 weeks of gestation and to compare the performance with those of cardiothoracic diameter ratio (CTR) and middle cerebral artery peak systolic velocity (MCA-PSV). METHODS: Fetuses at risk of Hb Bart's disease between 18 and 22 weeks of gestation prospectively underwent echocardiography with acquisition of the volume datasets (VDS) of fetal heart, using 4D-cardiac STIC. Subsequently, off-line analysis was blindly performed to measure cardiac volume using the VOCAL technique. RESULTS: A total of 502 fetuses at risk meeting the inclusion criteria were included in the analysis, consisting of 117 (23.3%) fetuses with Hb Bart's disease and 385 (76.7%) unaffected fetuses. The mean (±SD) gestational age at the time of ultrasound examination was 19.70 ± 1.3 weeks. In predicting fetal Hb Bart's disease, CV, using a cut-off Z-score of 1.7, had a sensitivity of 94.9% and specificity of 94.0%. The performance of CV was slightly better than that of CTR but very superior to that of MCA-PSV (areas under curve: 0.988, 0.974 and 0.862, respectively). CONCLUSIONS: Fetal CV has a very high performance in predicting fetal Hb Bart's disease at mid-pregnancy, comparable with CTR and much better than MCA-PSV.