Severe acute malnutrition (SAM) is a huge global public health issue which is up till now a significant cause of childhood mortality all over the world [12, 13].
This study revealed that the majority of malnourished children were related to rural residents with low or very low social standards and these results may be due to the fact that undernutrition is strongly related to the low income and social standard and also, it is related with the rural conditions. Different authors documented that severe acute malnutrition is associated with the poor standard of living and living in rural regions [14,15,16]. The association of a higher percentage of breastfeeding with malnutrition in our study (66.7%) suggests that breastfeeding in these cases was insufficient for their normal growth which may be due to prolonged breastfeeding, breastfeeding without optimal supplementation or if the mother is weak, underweight and malnourished related to their poor socioeconomic standards and this was in agreement with Berkley et al., 2005 .
The most common comorbidities detected with malnourished were dehydration, followed by bronchopneumonia and gastroenteritis. These ratios were close to those reported by Kerac et al., (2010), WHO (2013), Chisti et al., (2014) and Manisha et al., 2016 [2, 18,19,20].
Tissue Doppler imaging for children with SAM at admission in comparison to healthy controls; found no affection of the left ventricular systolic function parameters including ejection fraction (EF) and fractional shortening (FS) in both groups. Comes inline with our result was Olivares et al., who reported no affection in systolic function in children with PEM .
However, Singh et al., 1989, Phornphatkul et al., 1994 and Nagla et al., 2010 reported that children with severe cases of PEM with more than 40% loss of the expected weight have reduced LV systolic function [22,23,24].
The variability of the aforementioned results could be attributed to other factors, for instance, the severity of the electrolyte imbalance or trace element deficiency which affect LV systolic function.
A diastolic dysfunction in 70% of malnourished children was reported in our study. In more details; a significantly decreased E velocities, indicating diastolic myocardial abnormalities, and increased E/e′ ratio at the lateral wall, which is a correlate of myocardial relaxation and LV filling pressure, in comparison to the healthy control children. Moreover, a negative but insignificant correlation between height for age Z score and E/e′ was documented in children suffering from SAM.
Although our studied children with SAM have significantly lower hemoglobin, ionized calcium and serum potassium levels in comparison to the healthy control group but, the degree of diastolic dysfunction detected in those patients was not correlated with these deficiencies.
The previous findings reported in our study were on the contrary to El-Sayed et al., 2006 and Nagla et al., 2010 where no alteration in E or E/e′ were detected in patients with PEM in comparison to control group using echocardiography [25, 24].
Nutritional rehabilitation was palned according to WHO standardized protocol for management of severe malnutrition and complications were managed accordingly .
Similar to the results obtained by Kerac et al., 2014, Public Health Foundation of India, 2012, Stettler and Iotova, 2010 and Dulloo, 2008 [26,27,28,29], a marked improvement was observed in all anthropometric indices of studied severely malnourished children after nutritional rehabilitation, regarding WHZ, WAZ and MUAC.
Marked improvement in hemoglobin level and normalization of TLC count, serum potassium, and serum calcium were detected in children with SAM at discharge from nutrition rehabilitation program and these data are in agreement with the results in other studies [24, 26].
During the treatment course at hospital, 2 cases died due to septic shock and this happened within two weeks after admission, their TDI revealed diastolic dysfunction grade II .
TDI for children with SAM post rehabilitation showed that 65% have a normal diastolic function in comparison to pre-rehabilitation with 70% diastolic dysfunction (P value > 0.001). Different degrees of positive correlations between diastolic function and anthropometric measurements (WAZ, HAZ, WHZ, MUAC) after rehabilitation were detected. Recently, Spaulding et al., 2016 reported that children with severe malnutrition suffer cardiac muscle wasting and ventricular dysfunction that responds well to nutritional rehabilitation therapy, also Nagla et al., 2010 concluded that nutritional rehabilitation reverses cardiac abnormalities significantly [3, 24].
The current study is the first to evaluate ventricular dysfunction by TDI in children with SAM. This differences between this study and other studies could be attributed to the variable subject ages or the different disease severity and/or duration.
We concluded from our study that most children with SAM have ventricular diastolic dysfunction which improves to a great extent after nutritional rehabilitation. Impaired diastolic function in malnourished children may be a predictor of mortality in these cases. Also, we recommend the use of Tissue Doppler as a follow-up tool for prognostic evaluation and risk stratification in severely malnourished children as it has the advantage of simple, easy detection, lower expense, easily repeated measurement and convenient monitoring of outcome.