Impact of the COVID pandemic on quality measures in a pediatric echocardiography lab.

Background: The COVID pandemic necessitated an altered approach to transthoracic echocardiography, especially in COVID cases. Whether this has effected echocardiography lab quality is unknown. Objectives: We sought to determine whether echocardiography lab quality measures during the COVID pandemic were different from those prior to the pandemic and whether quality and comprehensiveness of echocardiograms performed during the pandemic was different between COVID and non-COVID patients. Methods: The four quality measures (diagnostic errors, appropriateness of echocardiogram, American College of Cardiology Image Quality metric and Comprehensive Exam metric in structurally normal hearts) reported quarterly in our lab were compared between two quarters during COVID (2020) and pre-COVID (2019). Each component of these metrics was also assessed in randomly selected echocardiograms in COVID patients and compared to non-COVID echocardiograms. Results: For non-COVID echocardiograms, the image quality metric did not change between 2019 and 2020 and the comprehensive exam metric improved. Diagnostic error rate did not change, and appropriateness of echocardiogram indications improved. When COVID and non-COVID echocardiograms were compared, the image quality metric and comprehensiveness exam metric were lower for COVID cases (image quality mean 21.3/23 for non-COVID, 18.6/23 for COVID, p < 0.001 and comprehensive exam mean 29.5/30 for non-COVID, 27.7/39 for COVID, p < 0.001). In particular, systemic and pulmonary veins, pulmonary arteries and aortic arch were not adequately imaged in COVID patients. For studies in which a follow-up echocardiogram was available, no new pathology was found. Conclusions: At our center, though diagnostic error rate did not change during the pandemic and the proportion of echocardiograms ordered for appropriate indications increased, imaging quality in COVID patients was compromised, especially for systemic and pulmonary veins, pulmonary arteries and arch. Though no new pathology was noted on the small number of patients who had follow-up studies, we are paying careful attention to these structures to avoid diagnostic errors going forward.

Frozen embryos? Torpor during pregnancy in the Tasmanian short-beaked echidna Tachyglossus aculeatus setosus.

We studied the interaction between torpor and reproduction in free-ranging female Tasmanian echidnas using a combination of techniques including urogenital smears, hormone analysis, ultrasonography, external temperature loggers and camera traps. Male echidnas initiated mating activity by locating hibernating females. All females that mated or were disturbed by males prior to July 27 re-entered hibernation, including many that were pregnant. Pregnant females only entered hibernation in early pregnancy when plasma progesterone concentrations were about twice basal and progesterone then remained constant during torpor. By re-entering hibernation pregnant females extended their gestation period and delayed egg-laying. Progesterone peaked 4-6days before egg-laying, then dropped rapidly.

Tissue Doppler imaging during exercise stress echocardiography demonstrates a mechanism for impaired exercise performance in children with hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is associated with decreased exercise tolerance in children, presumably due to diastolic dysfunction. Modern imaging techniques to assess myocardial function during active exercise have not been applied to this population. We hypothesized that impaired contractile reserve, as assessed by tissue Doppler imaging (TDI) and strain, contributes to reduced exercise capacity in affected individuals. METHODS: Children (<18 years) with HCM and healthy age- and sex-matched controls were prospectively enrolled. Resting echocardiograms and staged upright cycle ergometry with simultaneous echocardiograms were performed. During exercise, left ventricular outflow tract (LVOT) gradients and color Doppler maps of apical four-chamber and parasternal short-axis views were obtained. Post processing of images was performed to obtain TDI velocities, and measurements of strain were attempted. Exercise parameters and staged TDI values were compared. RESULTS: The study population consisted of 58 subjects (22 with HCM and 36 controls). Patients with HCM had significantly higher peak LVOT gradients compared to controls at baseline and at each exercise stage. TDI revealed that diastolic function, as assessed by E' velocities at septal and lateral mitral annuli, normalized with exercise in HCM patients. Further, systolic function (S' velocity) of HCM patients at rest was normal but failed to augment normally at peak exercise. CONCLUSIONS: Children with HCM have decreased TDI velocities at rest. With exercise, they may increase their E' velocities but fail to augment S' velocities, demonstrating decreased contractile reserve. In the patient with suspected HCM but equivocal findings, exercise TDI assessment may complement the diagnostic evaluation.

Improvement in Tricuspid Annular Plane Systolic Excursion with Pulmonary Hypertension Therapy in Pediatric Patients.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE) has emerged as a novel and reliable measure of right ventricular (RV) function. The purpose of this study was to determine the effect of pulmonary hypertension (PH) therapy on TAPSE in pediatric patients and compare TAPSE to other quantitative measures of RV function. METHODS: A retrospective review of medical records and echocardiograms of patients in the PH clinic from January 2011 to August 2013 was done. Echocardiograms were analyzed prior to initiation or addition of a PH drug and at least 8 weeks later. Following quantitative measures of RV function were compared: TAPSE, TAPSE age-based z-score, RV fractional area change (RVFAC), tricuspid annular S', tricuspid inflow E/tricuspid annular E' velocity (TV E/E'), and RV myocardial performance index (RVMPI). RESULTS: Of the 37 patients included in this study (median age 0.6 years), 23 (62.2%) were treatment naive and others had a new PH drug added to their regimen at the time of the baseline echocardiogram. The median duration between the baseline and follow-up echocardiogram was 8 (2-25) months. There was a significant improvement in TAPSE and TAPSE age-based z-score on the follow-up echocardiogram. RVFAC, tricuspid S', TV E/E', and RVMPI did not show a statistically significant change. CONCLUSION: In contrast to the other echocardiographic markers of RV function, TAPSE, and TAPSE age-based z-score significantly improve after initiation or addition of PH therapy and can be used for serial noninvasive monitoring of RV function in pediatric PH patients.

Rationale and design of the Children's Oncology Group study AAML1831 integrated cardiac substudies in pediatric acute myeloid leukemia therapy.

Background: Pediatric acute myeloid leukemia (AML) therapy is associated with substantial short- and long-term treatment-related cardiotoxicity mainly due to high-dose anthracycline exposure. Early left ventricular systolic dysfunction (LVSD) compromises anthracycline delivery and is associated with inferior event-free and overall survival in de novo pediatric AML. Thus, effective cardioprotective strategies and cardiotoxicity risk predictors are critical to optimize cancer therapy delivery and enable early interventions to prevent progressive LVSD. While dexrazoxane-based cardioprotection reduces short-term cardiotoxicity without compromising cancer survival, liposomal anthracycline formulations have the potential to mitigate cardiotoxicity while improving antitumor efficacy. This overview summarizes the rationale and methodology of cardiac substudies within AAML1831, a randomized Children's Oncology Group Phase 3 study of CPX-351, a liposomal formulation of daunorubicin and cytarabine, in comparison with standard daunorubicin/cytarabine with dexrazoxane in the treatment of de novo pediatric AML. Methods/design: Children (age <22 years) with newly diagnosed AML were enrolled and randomized to CPX-351-containing induction 1 and 2 (Arm A) or standard daunorubicin and dexrazoxane-containing induction (Arm B). Embedded cardiac correlative studies aim to compare the efficacy of this liposomal anthracycline formulation to dexrazoxane for primary prevention of cardiotoxicity by detailed core lab analysis of standardized echocardiograms and serial cardiac biomarkers throughout AML therapy and in follow-up. In addition, AAML1831 will assess the ability of early changes in sensitive echo indices (e.g., global longitudinal strain) and cardiac biomarkers (e.g., troponin and natriuretic peptides) to predict subsequent LVSD. Finally, AAML1831 establishes expert consensus-based strategies in cardiac monitoring and anthracycline dose modification to balance the potentially competing priorities of cardiotoxicity reduction with optimal leukemia therapy. Discussion: This study will inform diagnostic, prognostic, preventative, and treatment strategies regarding cardiotoxicity during pediatric AML therapy. Together, these measures have the potential to improve leukemia-free and overall survival and long-term cardiovascular health in children with AML. Clinical trial registration: https://clinicaltrials.gov/, identifier NCT04293562.

Preoperative echocardiographic measures in interrupted aortic arch: Which ones best predict surgical approach and outcome?

OBJECTIVE: It is unclear whether neonates with interrupted aortic arch (IAA) and a smaller left ventricular outflow tract may have improved outcomes with a Yasui operation (ventricular outflow bypass procedure) over a primary complete repair. This study sought to identify preoperative echocardiographic parameters to differentiate which neonates may have improved outcomes with a primary vs Yasui operation. DESIGN: Patient demographics, cardiac surgery type, complications, need for reoperation and/or interventional catheterization, and date of last follow-up were collected on neonates who underwent a biventricular repair for IAA from 2003 to 2014. Preoperative echocardiograms were analyzed for: IAA type, valve annulus size, aortic valve morphology, ventricular size and aortic arch anatomy. RESULTS: Seventy-seven neonates underwent IAA repair between 2003 and 2013. 60 neonates had a primary repair and 17 a Yasui operation. Neonates that underwent a Yasui operation had significantly smaller mitral and aortic valves with aortic arch hypoplasia. Within the primary repair group, a decreasing aortic root z-score on univariate analysis increased the odds of reoperation by twofold [OR = 1.98, 95% CI: (1.15-3.42), P = .014]. A significant interaction between repair type and aortic root z-score was identified on multivariable analysis (P = .039), for neonates with aortic root z-scores less than -2.5, the probability of reoperation during the follow up time period [mean 4.5 years (3.3 months-10 year)] was significantly higher in the primary repair group compared to the Yasui group (64.3% vs 37.5%). CONCLUSIONS: Neonates with IAA and an aortic root z-score less than -2.5 have lower odds of subsequent reoperations with a Yasui operation compared to a primary repair over the follow up period. These findings suggest a Yasui operation should be considered if the preoperative aortic root z-score is less than -2.5. Careful evaluation of these morphologic predictors on preoperative echocardiograms can be helpful in surgical planning in neonates with IAA.

Echocardiographic Predictors of Left Ventricular Outflow Tract Obstruction following Repair of Atrioventricular Septal Defect.

BACKGROUND: Left ventricular outflow tract obstruction (LVOTO) is a common complication following surgical repair of atrioventricular septal defect (AVSD). OBJECTIVE: We sought to determine predictors of LVOTO based on echocardiograms performed prior to initial repair of AVSD. METHODS: Of the 415 children that had repair of AVSD from 2003 to 2012, 17 children were identified with LVOTO that required surgical intervention. Thirty-four patients with repaired AVSD and no LVOTO served as controls. Patient demographics, cardiac surgery type, and echocardiogram results at last follow-up were collected. Off-line analysis of the echocardiogram prior to AVSD repair was done to obtain: left ventricular outflow tract (LVOT) and interventricular septal diameter, chordae across LVOT, aortoseptal angle, left ventricular (LV) inflow/outflow length ratio, inferior displacement of the atrioventricular (AV) valve, atrioventricular valve index (AVVI) and presence of coarctation of the aorta. RESULTS: The LVOTO group had significantly smaller indexed LVOT diameters (P < .001), increased likelihood of chordae crossing the LVOT (P = .010), decreased LV inflow/outflow length ratio (P < .001), decreased AVVI (P = .014) and increased presence of coarctation of the aorta (P = .003) compared to control patients. A multiple logistic regression model including presence of chordae in the LVOT [OR 5.32, 95% CI: (1.24-22.78, P = .024] and an indexed LVOT diameter ≤2.5 cm/m2 [OR 5.41, 95% CI: (1.15-25.39) P = .032] demonstrated each to be independently associated with the development of LVOT obstruction (area under the receiving operating curve = 0.77). CONCLUSIONS: Chordae across the LVOT and an indexed LVOT diameter of ≤2.5 cm/m2 are associated with a higher risk of development of LVOTO following repair of AVSD. Identification of these risk factors on echocardiogram prior to initial AVSD repair can be useful in evaluating for future risk of LVOTO and the need for closer clinical follow-up.

Cool sex? Hibernation and reproduction overlap in the echidna.

During hibernation there is a slowing of all metabolic processes, and thus it is normally considered to be incompatible with reproduction. In Tasmania the egg-laying mammal, the echidna (Tachyglossus aculeatus) hibernates for several months before mating in mid-winter, and in previous studies we observed males with females that were still hibernating. We monitored the reproductive activity of radio-tracked echidnas by swabbing the reproductive tract for sperm while external temperature loggers provided information on the timing of hibernation. Additional information was provided by camera traps and ultrasound imaging. More than a third of the females found in mating groups were torpid, and the majority of these had mated. Some females re-entered deep torpor for extended periods after mating. Ultrasound examination showed a developing egg in the uterus of a female that had repeatedly re-entered torpor. The presence of fresh sperm in cloacal swabs taken from this female on three occasions after her presumed date of fertilization indicated she mated several times after being fertilized. The mating of males with torpid females is the result of extreme competition between promiscuous males, while re-entry into hibernation by pregnant females could improve the possibility of mating with a better quality male.