This study is a prospective analytical case–control study on 34 infants and children. This study was conducted at a tertiary care university hospital from November 2022 to January 2024, with audible PDA.

A control group consisting of 20 healthy infants and children was included in the study for comparison of echocardiographic measurements.

Inclusion criteria

Patients in pediatric age ranging from 6 months to 18 years whose weight is over 6 kg with audible PDA with or without evidence of LV volume overload were included in the study.

Exclusion criteria

Patients with PDA not eligible for transcatheter closure

Patients with PDA suffer from other significant congenital heart diseases or irreversible pulmonary vascular diseases.

Patients evaluation

All Participants were evaluated as follows: complete history taking, full examination with special emphasis on anthropometric measurements, and local examination with detailed cardiac examination.

Investigations

All children were submitted to routine investigations, chest X-ray, ECG, and detailed transthoracic echocardiography (TTE) using different modes including 2D TTE, tissue Doppler imaging (TDI), and 2D STE.

A-Routine echocardiographic examination

B- Examination using tissue Doppler.

C- Speckling tracking imaging 2D echocardiography

Equipment

Machine: echocardiographic evaluation was done using a commercially available ultrasound transducer and equipment (Vivid E95, GE Healthcare, Horten, Norway).

Transducers: data acquisition was performed with a 3.5-MHz transducer, S7 probe. Workstation: Digital loops were obtained and analyzed using AFI software on the Equipment.

A) Routine echocardiographic examination

The study was done for all participants (cases and controls) using the standard views (apical, parasternal long axis, parasternal short axis, and subcostal) to gather all data required for comparison according to the American Society of Echocardiography guidelines (Figs. 1, 2, 3, and 4) [6].

Fig. 1

Apical 4 chamber view of 7-month-old patient with PDA

Fig. 2

M mode from PLAX view of 7-month-old patient

Fig. 3

Modified parasternal short axis view showing Hemodynamically significant PDA in 1-year-old patient measuring 3 mm at the pulmonary end

Fig. 4

PW-Doppler in PDA patient showing EA ratio 1.53

B) Examination using tissue Doppler (TDE)

Mitral annulus velocities:

PW-TDI sample volume is positioned at the septal mitral annulus producing three waves, an antegrade systolic wave S', and two retrograde waves, E' representing passive LV filling and A' wave representing atrial contraction.

Myocardial performance index of left ventricle (MPI):

The MPI was calculated using the Tei index which equals the difference between a’ and b’ divided by b’. a’ is the time from the end of the A'-wave to the beginning of the E'-wave and b’ is the time duration of the S' wave (Fig. 5).

Fig. 5

Tissue Doppler of 1.5-year-old patient with PDA, TEI index 0.62

C) Speckling tracking imaging transthoracic 2D echocardiographic examination

A 3.5-MHz transducer, S7 probe interfaced with a GE Vivid E95 ultrasound system was used to image each heart. We used the 2D LVQ AFI function of the device to assess global longitudinal, circumferential, and radial strain and area strain. Three views were obtained 4 chambers, 2 chambers, and APLAX (Figs. 6, 7, and 8 respectively).

Fig. 6

4-chamber view for AFI LV strain calculation

Fig. 7

2-chamber view for AFI LV strain calculation

Fig. 8

3-chamber view for AFI LV strain calculation

The speckle tracking of the left ventricle was done beginning from a region of interest (ROI) defined at the end of the systole. 2D strain analysis was performed at the end of the process in the 2D auto left ventricular auto quantification tool, which also calculated the volume and mass of the left ventricle. The meshes obtained from the two measurements were used for the 2D ROI strain. The 2D ROI strain was generated in an automatic manner using the end-systolic frame and was generated from an endocardial and an epicardial mesh (Fig. 9). The mesh of the endocardium was dependent on the one used for the measurement of end-systolic volume (ESV). The mesh of epicardium was produced automatically from the epicardial mesh used in the stage of left ventricle mass, by generating it from the end of diastole to the end of systole. The operator can adjust the shape of ROI by putting drawer points to pull the nearby ROI border towards where the operator wants it to go from the results of tracking, several parameters result from 2D strain, including longitudinal, circumferential, area, and radial strain.

Fig. 9

Bull’s eye of a 1.5-year-old patient with hemodynamically significant PDA. GS was 18.4%

Assessment of variability

For the assessment of intra-observer variability, the same operator twice measured the analysis of the 2D strain of 15 participants who were selected randomly at an interval of 2 months to avoid recall bias. For interobserver variability assessment, the measurements of 2D strain were operated by a second observer who was not informed of the results of the first operator.

Statistical analysis and data interpretation

SPSS software, version 25 (SPSS Inc., PASW statistics for Windows version 25. Chicago: SPSS Inc.) was used for the analysis of data. Number and percent described qualitative data. Median (minimum and maximum) used in quantitative data for non-normally distributed data and mean (Standard deviation) for normally distributed data after using the Kolmogrov-Smirnov test or testing normality.

The judgment of the result’s significance was at the (≤ 0.05) level.

We used chi-square, Monte Carlo tests, and Fisher exact test for qualitative data comparison between groups.

We used the Mann–Whitney U test for comparison between 2 studied groups for non-normally distributed data.

We used the Student t-test for comparison of the 2 independent groups for normally distributed data.

We used the Wilcoxon signed rank test for comparison between 2 studied periods for non-normally distributed data.