1025 Global strain rate do not reduce biological variability compared to S", and do not normalize for body size

Background As the Left ventricular (LV) apex is stationary, and maximum velocities are in the mitral plane, peak systolic annular velocity (S") normalized for wall length (WL) is a measure of peak systolic strain rate (Fig. 1), as is strain rate measured by tissue Doppler. As the normalization presumably corrects for the size of the heart (and thus body), this should reduce biological variability, but this assumption has previously been shown to be faulty for annular displacement (MAPSE) vs global longitudinal strain. Methods The HUNT study examined 1266 subjects without evidence of heart disease, from a mixed urban / rural population of North Tøndelag county in Norway. Annular systolic velocity was measured by pulsed-wave Tissue Doppler in the septal, lateral, anterior and inferior points, and averaged. Wall lengths was measured in a straight line in the same points, and S" was normalized (S"/WL) and averaged. Segmental systolic strain rate was also measured by combined speckle tracking / Tissue Doppler and averaged to a global value (GLSR). Results are given in table 1. All three measures declined with increasing age (R was -0.23, -0.29 and -0.29, respectively, all p < 0.001) The over-all relative standard deviations were similar for S", normalized S" and global strain rate. Both S"/WL and GLSR correlated negatively with BSA, R was - 0.22 and 0.17, respectively (p < 0.001), while S" showed a modest positive correlation; R = 0.13, (p < 0.001) Conclusion Normalizing peak systolic mitral annular velocity for length do not reduce biological variability, and introduces a systematic error in the body size relation, due to the one-dimensional nature of the normalisation, and the three-dimensional nature of LV deformation. This is in accordance with what has previously been shown for global longitudinal strain vs. annular plane displacement. Table 1 Age (years) S" (cm/s) S"/WL (/s) GLSR (/s) < 40 9.1 (1.2) 0.93 (0.13) 1.08 (0.12) 40 - 60 8.3 (1.3) 0.86 (0.13) 1.03 (0.12) > 60 7.7 (1.3) 0.81 (0.14) 0.98 (0.14) All 8.4 (1.4) 0.87 (0.14) 1.03 (0.13) Relative SD (%) 16.7 16.1 12.6 Mitral annular velocity (S"), normalised velocity (S"/WL) and Global strain by age groups. (Standard deviations in parentheses) Abstract 1025 Figure. Fig. 1

Focal Myocarditis in Professonal Female Athlete: A Case Report

A 35-year-old female athlete appealed to her sports physician on new onset of frequent palpitations, just before an important competition. Initial electrocardiography revealed unifocal premature ventricular complexes in the form of bigeminy. Echocardiography revealed fine-granulated hyperdensic changes in septum. Global strain rate was within a range normal, as well as pulsed tissue Doppler ultrasound. Patient was referred for cardiac MRI, which revealed interventricular septum with rougher compounds, but with preserved continuity, with thickness of 10 mm, which is in the middle of the LV, in length of 5 mm, thinned to a thickness of 4 mm. ELISA laboratory test demonstrated an increased titer of IgM antibodies for adenovirus. Six months later, the patient was referred for control MRI of the heart, which showed pronounced trabeculation of infero-lateral wall of the left ventricle, but without certain criteria for non-compaction cardiomyopathy. There was T1 oedema component in apical septal segment and apical segment of the left ventricle. There was increase of the signal in late gadolinium enhancement in the medial parts of the same segments but also in the segment of the basomedial septum, with previous focal myocarditis. These findings suggest myocardial fibrosis in the segments that were stricken by myocarditis, now without active ongoing myocarditis, but without consequent myocardial fibrosis.

EXPERIMENTAL STUDY OF TURBULENT LPG TURBULENT INVERSE DIFFUSION FLAME IN COAXIAL BURNER

The present experimental study investigates the turbulent LPG Inverse Diffusion Flame (IDF) stabilized in a coaxial burner in terms of flame appearance, visible flame length, centerline temperature distribution and oxygen concentration and NOX emission characteristics. The effect of air-fuel jet velocities on visible flame length is interpreted using global strain rate and a new devised parameter called Modified Momentum Ratio. The centerline temperature exhibits a steeper increase in the lower premixed zone of the IDF due to the enhanced premixing. Subsequently it declines gradually in the upper luminous portion owing to soot radiation and heat losses to the ambient. Further, the centerline oxygen depletes rapidly in the lower blue zone but found to increase gradually in the upper luminous portion of IDF. The centerline temperature and oxygen distribution along the flame length revealed the dual flame structure of IDF. The EINOX values exhibited a bell shaped profile and reached a maximum value around stoichiometric overall equivalence ratio.