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Page 16 of 23 Rao. Vessel Plus 2022;6:24 https://dx.doi.org/10.20517/2574-1209.2021.91

AS = [(LVAd - LVAs)/LVAd] × 100

AS, area shortening; LVAd, LV area in diastole; and LVAs, LV area in systole.

These can easily be recorded with any of the modern echocardiographic machines [Figure 20]. The normal
[19]
values are 55% to 75% . This method of evaluation of LV function is helpful even in the presence of LV
dysynergy or flat-to-paradoxical septal motion, but is still load-dependent.

Right or single ventricle
Right and single ventricles have bizarre shapes and are not amenable to ellipsoid resolution techniques that
are used for the LV. Consequently, most cardiologists used to use qualitative visual estimates of RV free wall
motion for RV systolic function or how both the free ventricular wall and inter-ventricular septum move for
the function of the single ventricle. More recently, fractional area change of the RV , tricuspid valve
[26]
annular plane systolic excursion , performance index of the RV myocardium (Tei index) , and tricuspid
[27]
[28]
regurgitation jet dP/dt (normal value: dP/dt > 400 mmHg/s) have been successfully used to evaluate the
[29]
RV function.
UTILITY OF ECHOCARDIOGRAPHY IN EVALUATING MULTIPLE NEONATAL ISSUES
Neonate in distress
Cyanosis and respiratory distress due to non-cardiac causes may be seen in a number of neonates [30,31] . The
non-cardiac causes are multiple: (1) diseases of the pulmonary parenchyma - hyaline membrane disease,
pneumonia, aspiration syndrome, and rare conditions like bronco-pulmonary dysplasia, pulmonary
hemorrhage, and Wilson-Mikity syndrome; (2) disorders producing mechanical interference of the function
of the lung - pneumothorax, pneumo-mediastinum, diaphragmatic hernia, tracheo-esophageal fistula, and
lobar emphysema; (3) persistent fetal circulation; (4) neonatal asphyxia; (5) disorders of the central nervous
system - intracranial hemorrhage, intra-cerebral malformations, severe intracranial infections, and primary
seizure disorders; (6) polycythemia; (7) methemoglobinemia; (8) hypoglycemia; (9) pulmonary (lung)
hypoplasia; (10) shock and sepsis; and (11) maternal drug transmission or effects of withdrawal; and others.
Neonates with all these disease entities are expected to have structurally normal hearts. Evaluation of such
infants with echo-Doppler examination can unmistakably show that the heart anatomy and function are
normal. In a few babies accompanying CCD may be discovered, which should be dealt with on the basis of
the degree of hemodynamic abnormality.

In some neonates, the PA pressures are increased and in others depressed LV or RV function may be
present; these and other issues can be clarified by the echocardiographic evaluation as discussed in the
earlier portions of this paper and provide assistance in the clinical management.

Infant of diabetic mother
Infant of diabetic mother (IDM) babies have a higher incidence of CCDs and persistent pulmonary
hypertension than normal infants. These abnormalities can easily be identified by echo-Doppler studies.
IDM babies also frequently exhibit hypertrophy of the LV, similar to that seen in hypertrophic
cardiomyopathy (HCM). The LV posterior wall and inter-ventricular septal thickness can easily be seen and
measured by echocardiography; there is usually a disproportionate ventricular septal hypertrophy
[Figure 21]. The ventricular cavity is almost completely obliterated during systole [Figure 22]. If there is LV
outflow tract obstruction, this can be visualized and quantified by Doppler studies [Figure 23]. The LV
hypertrophy of IDMs resolves with time (usually by 3 to 6 months) in contradistinction to HCM in which
there will be no regression of LV hypertrophy; the hypertrophy may even increase in severity with time.