Doppler tissue imaging in children following cardiac transplantation: a comparison to catheter derived hemodynamics.

Previous studies have demonstrated a correlation between E:E(a) and ventricular filling pressure in adults after heart transplantation. We sought to determine if E:E(a) correlates with filling pressure after heart transplantation in children. A prospective analysis of children who have undergone heart transplantation was performed. Inflow and myocardial velocities were recorded and compared to catheter-derived filling pressures and rejection status. We performed 61 studies in 49 subjects. No correlation was found between septal E:E(a) and PCWP (r=0.14, p=0.28); or between lateral tricuspid E:E(a) and mean RAp (r=0.04, p=0.79). However, the mean PCWP was higher among subjects with elevated septal E:E(a) (>12) compared to normal E:E(a) (12.3±2.8mmHg vs. 10.1±2.9mmHg, p=0.02). Similarly, mean RAp was higher among subjects with an elevated lateral tricuspid E:E(a) (>10) compared to normal lateral tricuspid E:E(a) (7.7±2.1mmHg vs. 6.0±2.4mmHg, p=0.04). Elevated septal E:E(a) was also associated with high-grade cellular rejection (OR=17.3 [95% CI 1.4-221], p=0.028). In children following heart transplant, E:E(a) does not correlate well with the range of filling pressures seen after pediatric heart transplantation. However, a septal E:E(a)>12 is associated with elevated PCWP and high grade cellular rejection and a lateral tricuspid E:E(a)>10 is associated with elevated mean RAp.

Cardiac Output Measurement Using the Ultrasonic Cardiac Output Monitor: A Validation Study in Newborn Infants.

OBJECTIVES: We aimed to determine the accuracy and validity of the Ultrasonic Cardiac Output Monitor (USCOM) measurements of cardiac output (CO) compared to echocardiography in newborn infants, and the inter-rater agreement of USCOM measurements. METHODS: In a single-center study we prospectively evaluated neonates undergoing an echocardiographic evaluation. USCOM measurements of CO were obtained at the pulmonary and aortic valve by 2 physicians blinded to the echocardiographic results. All echocardiographic measurements were performed blinded to USCOM measurements. We first enrolled an ascertainment cohort which was subsequently validated in an independent new cohort. Agreement between echocardiography and USCOM methods was assessed by Bland-Altman analysis. Intra-class correlation coefficients (ICC) assessed the agreement between the 2 operators. The ascertainment cohort correction factors were applied in a second validation cohort and agreement of the calibrated measures evaluated with repeat Bland-Altman comparisons. RESULTS: A total of 50 infants were enrolled in the initial cohort and 15 in the validation cohort. There was a high degree of correlation between the USCOM operators (ICC = 0.975). USCOM measurements of CO were significantly higher compared to echocardiography (left ventricular output bias 95 ± 52 mL/kg/min and right ventricular output bias 64 ± 30 mL/kg/min). There was no difference in the subgroup of infants with and without a ductus arteriosus. After the correction was applied to the validation cohort, there was no longer a significant difference between the measures. CONCLUSIONS: CO measured by USCOM consistently overestimated the results obtained from echocardiography. USCOM is not adequate to provide absolute estimates of CO. However, it may allow longitudinal hemodynamic assessment of sick neonates.

Following the arterial switch operation, obese children have risk factors for early cardiovascular disease.

BACKGROUND: Children who have undergone the arterial switch operation (ASO) are at risk for premature coronary artery disease due to coronary re-implantation. Obesity may also pose cardiovascular risk. The purpose of this study was to evaluate comorbidities and markers of early cardiovascular disease in obese ASO patients. METHODS: Obese [body mass index (BMI) >or= 95th %] and normal weight (NW, BMI < 85th %) ASO patients, and NW controls without heart disease were enrolled, and underwent prospective vascular, echocardiographic, laboratory, exercise, and ambulatory blood pressure (BP) testing. Results were compared between groups. BP load was defined as proportion of recordings >or= 95th %. RESULTS: Thirty patients [13.2 years (11.2-16.8), 57% male] were evaluated: 10 obese ASO, 10 NW ASO, and 10 NW controls. Obese ASO patients, in comparison to NW ASO and controls, had higher systolic BP% [96% (90-99) vs. 67% (30-91) P= 0.07 (trend) and 34% (21-43) P= 0.005], night-time diastolic BP load [18% (14-24) vs. 0% (0-0) P= 0.01 and 0% (0-0) P= 0.01], left ventricular mass index [51.7 g/m(2.7) (46.6-53.3) vs. 40.7 g/m(2.7) (29.2-41.6) P < 0.01 and 28.9 g/m(2.7) (27.3-33.7) P < 0.01], and lower brachial artery reactivity [8.7% (6.2-11.9) vs. 14.6% (10.8-23.0) P= 0.03, and 16.7% (12.8-17.8) P= 0.05]. There was a trend toward increased carotid intima-media thickness, and significantly higher triglyceride and lower high-density lipoprotein levels in obese ASO patients. CONCLUSIONS: Following the ASO, obese patients have associated comorbidities, and markers of early cardiovascular disease. These may pose additional risk for future cardiovascular events in this unique population who underwent coronary artery re-implantation in infancy.