Left Ventricular Function after Arterial Switch Operation as Assessed by Two-Dimensional Speckle-Tracking
Elaheh Malakan Rad1, Yazdan Ghandi2, Armen Kocharian1
1Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran .
Insights
Children with transposition of the great arteries (TGA) after arterial switch operation (ASO) showed normal left ventricular strain and time to peak strain parameters. However, left ventricular myocardial time to peak strain rate did not normalize within 18 months post-ASO.
Area of Science:
- Cardiology
- Pediatric Cardiac Surgery
- Echocardiography
Background:
- Transposition of the great arteries (TGA) with intact ventricular septum (IVS) requires arterial switch operation (ASO).
- Coronary artery damage is a risk during ASO, impacting late postoperative outcomes.
- Assessing left ventricular (LV) function post-ASO is crucial for patient management.
Purpose of the Study:
- To investigate LV function in pediatric patients with TGA/IVS after ASO using echocardiography.
- To compare echocardiographic parameters between TGA/IVS patients and a control group.
Main Methods:
- 2D speckle-tracking echocardiography (2D STE) was used to evaluate 20 infants with TGA/IVS more than 6 months post-ASO.
- LV longitudinal strain (S), strain rate (SR), time to peak systolic longitudinal strain (TPS), and time to peak systolic longitudinal strain rate (TPSR) were measured.
- Patients were compared to an age-matched control group.
Main Results:
- Global strain (S), TPSR, and TPS were not significantly different between TGA/IVS patients and controls.
- Global strain rate (SR) was significantly different (p < 0.001) between groups.
- Specific regional wall analyses showed significant differences in S and SR in certain views, while others did not differ significantly.
Conclusions:
- LV strain (S), strain rate (SR), and global time to peak strain (TPS) parameters normalize between 6 and 18 months post-ASO in TGA/IVS patients.
- LV myocardial time to peak strain rate (TPSR) remains abnormal in this period, indicating potential subtle myocardial dysfunction.
Abstract:
Background: The late postoperative course for children with transposition of the great arteries (TGA) with an intact ventricular septum (IVS) is very important because the coronary arteries may be at risk of damage during arterial switch operation (ASO). We sought to investigate left ventricular function in patients with TGA/IVS by echocardiography. Methods: From March 2011 to December 2012, totally 20 infants (12 males and 8 females) with TGA/IVS were evaluated via 2-dimensional speckle-tracking echocardiography (2D STE) more than 6 months after they underwent ASO. A control group of age-matched infants and children was also studied. Left ventricular longitudinal strain (S), strain rate (SR), time to peak systolic longitudinal strain (TPS), and time to peak systolic longitudinal strain rate (TPSR) were measured and compared between the 2 groups. Results: Mean ± SD of age at the time of study in the patients with TGA/IVS was 15 ± 5 months, and also age at the time of ASO was 12 ± 3 days. Weight was 3.13 ± 0.07 kg at birth and 8.83 ± 1.57 kg at the time of ASO. Global strain (S), Time to peak strain rate (TPSR), and Time to peak strain (TPS) were not significantly different between the 2 groups, whereas global strain rate (SR) was significantly different (p value < 0.001). In the 3-chamber view, the values of S in the lateral, septal, inferior, and anteroseptal walls were significantly different between the 2 groups (p value < 0.001), and SR in the posterior wall was significantly different between the 2 groups (p value < 0.001). There were no positive correlations between S and SR in terms of the variables of heart rate, total cardiopulmonary bypass time, and aortic cross-clamp time. There were no statistically significant differences between the 2 groups regarding S, SR, TPS, and TPSR in the anteroseptal and posterior walls in the 3-chamber view and in the lateral and septal walls in the 4-chamber view. Conclusion: We showed that between 6 and 18 months after a successful ASO, the parameters of S, SR, and global TPS were normal in our patients with TGA/IVS. However, LV myocardial TPSR did not normalize in this time period.
