The diastolic inflow and longitudinal movement of the heart in the African full-term new-born infant

Abstract

Introduction: Echocardiography has been used mainly to assess the contractility of the left where do you find the staff that ventricle (LV) and its systolic function. The diastolic component of the cardiac cycle is an important component of cardiac output but has been under-explored, especially in neonates. Methodology: The aim of this study was to determine normal echocardiographic references for diastolic inflow and longitudinal movement of both the left and right heart in healthy full-term black African neonates. A descriptive, bidirectional study design was employed. Healthy African (Black) full-term infants who met inclusion criteria were recruited at the Chris Hani Baragwanath Academic Hospital. The study consisted of 2 series: a retrospective post processing of data and a prospective data collection. Left and right ventricular (RV) systolic and diastolic function were assessed using multiple echocardiographic methods Myocardial performance indexes of the RV and LV were calculated using mitral and tricuspid valve inflow patterns, and the aortic valve outflow Doppler envelope in the case of the LV myocardial performance index (MPI) and the pulmonary valve outflow measurement in the case of RV MPI. Statistical analysis was performed using Excel and Statistica version 13.1. Normal ranges were calculated using means ± standard deviations. Results: Two hundred and ninety-two neonates (142 males, 152 females; median gestational age 39 weeks, range 37-42 weeks) were included in the study. Most of the subjects (175/292;60%) were born by caesarean section. Median body surface area was 0.20 m2 (range, 0.16-0.25m2 ). Median weight was 3.12 kg (range, 2.5 kg 4.43kg). Median post-delivery age at echocardiography was 31 hours (range, 12-216 hours).The following measurements (means ± SD) were observed: LVEF and LVFS were 73.56% (±8.93) and 40.34% (±7.91) respectively. Mitral valve (MV) peak E= 0.58 m/s (±0.113), MV peak A = 0.59 m/s (±0.123), MV peak E/A ratio = 1.01 (±0.21), MV E’ = 0.058 m/s (±0.012), MV E/E’ ratio = 10.38 (±2.65), MV S’ = 0.052 m/s (±0.009) and LV Tei = 0.306 (±0.139). Right ventricular (RV) function measurements were: TAPSE = 7.51mm (±1.304), tricuspid valve (TV) peak E = 0.512 m/s (±0.126), TV peak A = 0.616 m/s (±0.127), TV E/A = 0.845 (±0.199), TV E’ = 0.079 m/s (±0.021), TV E/E’ ratio = 6.78 (±2.02), TV S’ = 0.071 m/s (±0.045) and RV Tei = 0.283 (±0.132). Conclusion: This large study established normal reference values for diastolic function and longitudinal systolic and diastolic movement of the heart in healthy full-term African neonates on echocardiography.