Minute Stroke Distance Is a More Reproducible Measurement Than Cardiac Output in the Assessment of Fetal Ventricular Systolic Function.

BACKGROUND: Echocardiographic quantification of fetal cardiac output (CO) aids clinical decision-making in the management of various cardiac and extracardiac diseases. Small variability in measuring semilunar valve dimension significantly reduces the reproducibility of the calculated CO. The authors propose minute stroke distance or velocity-time integral (VTI) as a more reproducible measure reflecting fetal ventricular systolic function. The aim of this study was to test the hypothesis that right and left ventricular minute VTI increase predictably with estimated fetal weight and are more reproducible than CO. METHODS: Five hundred seventy-one singleton fetuses without cardiovascular pathology between 16 and 36 weeks' gestation were reviewed retrospectively. Twenty-two fetuses with pathology resulting in low- or high-CO states were also assessed for comparison. VTI was measured in both ventricular outflow tracts at the level of the semilunar valve, excluding a Doppler insonation angle of >30°. Heart rate, semilunar valve dimension, and VTI determined minute VTI and CO. Inter- and intrarater variability were evaluated in a random 10% subset. RESULTS: Minute VTI and CO measurements were feasible in 67% to 89% of fetuses in this retrospective study. Minute VTI and CO increased with estimated fetal weight nonlinearly (R = 0.61-0.94). The mean inter- and intrarater variability for VTI, 6% and 5.7%, were significantly less than for CO, 25% and 23.7% (P < .001 for all). CONCLUSIONS: Minute VTI is an easily measured, highly reproducible method of quantifying fetal ventricular systolic function. Variability in calculated CO from valve measurement differences is minimized by solely using VTI. Nomograms of minute VTI provide an efficient and precise assessment of fetal systolic function and may be used to track fetuses in disease states with low or high CO.

Telehealth in Pediatric Heart Transplant Patients: Exercise, Nutrition, and Parental Imaging.

Telehealth is a promising new tool in medicine that has changed the landscape of medical care. The benefits of telehealth technology are immense, including improved access to care and potential savings in monetary and opportunity costs. Current challenges of incorporating telehealth services into regular clinical care include licensure and regulatory barriers, difficulty obtaining insurance reimbursements, and high costs of setting up successful telehealth infrastructures. These challenges threaten telehealth's future scalability and expansion to reach all patients in need.

Assessment of Progressive Pathophysiology After Early Prenatal Diagnosis of the Ebstein Anomaly or Tricuspid Valve Dysplasia.

In fetuses with Ebstein anomaly or tricuspid valve dysplasia (EA/TVD), poor hemodynamic status is associated with worse neonatal outcome. It is not known whether EA/TVD fetuses with more favorable physiology earlier in gestation progress to more severe disease in the third trimester. We evaluated if echocardiographic indexes in EA/TVD fetuses presenting <24 weeks of gestation are reliable indicators of physiologic status later in pregnancy. This multicenter, retrospective study included 51 fetuses presenting at <24 weeks of gestation with EA/TVD and serial fetal echocardiograms ≥4 weeks apart. We designated the following as markers of poor outcome: absence of anterograde flow across the pulmonary valve, pulmonary valve regurgitation, cardiothoracic area ratio >0.48, left ventricular (LV) dysfunction, or tricuspid valve (TV) annulus Z-score >5.6. Median gestational age at diagnosis was 21 weeks (range, 18 to 24). Eighteen fetuses (35%) had no markers for poor hemodynamic status initially, whereas only 7 of these continued to have no markers of poor outcome in the third trimester. Nine of 27 fetuses (33%) with anterograde pulmonary blood flow on the first echocardiogram developed pulmonary atresia; 7 of 39 (18%) developed new pulmonary valve regurgitation. LV dysfunction was present in 2 (4%) patients at <24 weeks but in 14 (37%) later (p <0.001). The TV annulus Z-score and cardiothoracic area both increased from diagnosis to follow-up. In conclusion, progressive hemodynamic compromise was common in this cohort. Our study highlights that care must be taken in counseling before 24 weeks, as the absence of factors associated with poor outcome early in pregnancy may be falsely reassuring.

Pediatric Echocardiography by Work Relative Value Units: Is Study Complexity Adequately Captured?

BACKGROUND: Present resource-based relative value unit (RVU) assignment for echocardiography is based on Current Procedural Terminology (CPT) codes, which do not incorporate complexity of diagnosis, time spent for image acquisition, or interpretation of echocardiograms. The objective of this study was to determine whether CPT-based RVU assignment accurately reflects physician effort in performing and interpreting pediatric echocardiographic examinations. METHODS: Cardiac complexity category (CCC) and physician time for study interpretation of 123 echocardiograms (June to September 2013) were prospectively assigned. Categories included (1) focused effusion/function evaluation, (2) normal anatomy/focused preterm infant studies, (3) acquired heart disease, (4) congenital heart disease excluding single ventricles, (5) single ventricles including heterotaxy syndrome, and (6) hearts on mechanical support. Subsequently, a random sample of echocardiograms (March to August 2013) were retrospectively analyzed, and each study was assigned a CCC and an extrapolated median interpretation time (MIT) on the basis of prospective data collection. Assigned work RVUs based on CPT codes were recorded. Comparisons were made between CCC and time for study interpretation, work RVUs, number of images acquired, and total scan time. RESULTS: A total of 933 echocardiograms were analyzed: 198 (21%), 174 (19%), 98 (11%), 359 (35%), 84 (9%), and 20 (2%) studies in CCCs 1 to 6, respectively. Total scan time, MIT, number of images, and work RVUs were different among CCCs (P < .0001). However, among the more complex studies (CCCs 2-5), work RVUs were similar, while number of images obtained and MIT were different (P < .001). Correlation analysis showed no association between work RVUs and CCC, total scan, or number of images per study. Compared with older patients, work RVUs of studies in children <2 years of age were lower, while all other markers of study complexity were higher (P < .05). CONCLUSIONS: Current CPT-based assignment of work RVUs does not discriminate study complexity and physician effort. The results of this study highlight the need for a refined system that accurately assesses physician effort in pediatric echocardiography.