No abstract

CO(EV) demonstrates acceptable agreement with data derived from CO(F) in infants and children with congenital heart disease. The new technique is simple, completely non-invasive, and provides beat-to-beat estimation of CO.

The embryonic heart tube consists of an outer myocardial tube, a middle layer of cardiac jelly, and an inner endocardial tube. It is said that tubular hearts pump the blood by peristaltoid contractions. The traditional concept of cardiac peristalsis sees the cyclic deformations of pulsating heart tubes as concentric narrowing and widening of tubes of circular cross-section. We have visualized the cross-sectional deformations of contracting embryonic hearts in chick embryos (HH-stages 9 -17) using real-time high-resolution optical coherence tomography. Cardiac contractions are detected from HH-stage 10 onward. During the cardiac cycle, the myocardial tube undergoes concentric narrowing and widening while the endocardial tube undergoes eccentric narrowing and widening, having an elliptic cross-section at end-diastole and a slitshaped cross-section at end-systole. The eccentric deformation of the endocardial tube is the consequence of an uneven distribution of the cardiac jelly. Our data show that the cyclic deformations of pulsating embryonic heart tubes run other than originally thought. There is evidence that heart tubes of elliptic cross-section might pump blood with a higher mechanical efficiency than those of circular-cross section. The uneven distribution of cardiac jelly seems to prefigure the future AV and cono-truncal endocardial cushions. Developmental Dynamics 237:953-961, 2008.

The objective of this study was to evaluate the reliability and accuracy of electrical cardiometry (EC) for the noninvasive determination of cardiac output (CO) in obese children and adolescents. We compared these results with those obtained by transthoracic echocardiography. Sixty-four participants underwent simultaneous measurement of CO. Cardiac output was measured by EC using the ICON(®) device. Simultaneously CO was determined by using transthoracic Doppler echocardiography from parasternal long-axis and apical view. The median age was 12.52 years (range 7.9-17.6 years) and 36 (56 %) were female. A strongly significant correlation was found between the COEC and COEcho measurements (p < 0.0001, r = 0.91). Significant correlations were also found between CO and age (r = 0.37, p = 0.002), weight (r = 0.57, p < 0.0001), height (0.60, p < 0.0001) and BMI (r = 0.42, p = 0.001). The mean difference between the two methods (COEC - COEcho) was 0.015 l min(-1). According to the Bland and Altman method, the upper and lower limits of agreement, defined as mean difference ±2 SD, were +1.21 and -0.91 l min(-1), respectively. Compared to the transthoracic Doppler echocardiography, Electrical Cardiometry provides accurate and reliable CO measurements in obese children and adolescents.