|Year : 2020 | Volume
| Issue : 2 | Page : 161-167
Immediate- and Short-Term Effect of Percutaneous Patent Ductus Arteriosus Closure on Left Ventricular Function: A Speckle Tracking Echocardiographic Study
Dina Adel Ezzeldin, Sherif Lotfy Wahba, Maiy Hamdy El Sayed, Alaa Mahmoud Roushdy
Department of Cardiology, Ain Shams University Hospitals, Cairo, Egypt
|Date of Submission||03-Jan-2020|
|Date of Decision||19-Feb-2020|
|Date of Acceptance||03-Mar-2020|
|Date of Web Publication||19-Aug-2020|
Dr. Dina Adel Ezzeldin
Department of Cardiology, Ain Shams University Hospitals, Abbassya, Cairo
Source of Support: None, Conflict of Interest: None
Background: Patent ductus arteriosus (PDA) closure results in a sudden drop in left ventricular (LV) preload, and this may affect the LV functions. Aim: The aim was to evaluate the immediate- and short-term changes in LV functions by speckle tracking echocardiography (STE) post percutaneous PDA closure. Materials and Methods: The study included 45 patients with PDA who were referred for PDA trans-catheter closure. All the patients included in the study underwent full echocardiographic examination and speckle tracking analysis before PDA closure, immediately after closure, and 1 month after the PDA closure. Results: There was no statistically significant change in LV functions by two-dimensional transthoracic echocardiography; the LV end-diastolic volume (EDV) decreased significantly in the immediate follow-up from 41.608 ± 25.8846 ml before duct closure to 36.317 ± 21.6945 ml. The drop in the LV EDV continued in the 1-month follow-up. The LV end-systolic volume decreased as well, however it took 1 month for this drop to be statistically significant. The LV end-diastolic dimension also decreased significantly after duct closure. Regarding STE results, the global LV strain and strain rate values did not significantly change. The global strain values had a mean of −22.944% ± 3.5128% before duct closure and decreased to a mean −22.028% ± 2.8932% immediately after duct closure. Conclusion: The study concluded that STE could be used to detect subtle changes in LV deformation. Time to peak systolic strain is an understudied parameter that needs further evaluation to provide a better understanding regarding its role in myocardial function assessment.
Keywords: Left ventricular remodeling, patent ductus arteriosus, speckle tracking echocardiography
|How to cite this article:|
Ezzeldin DA, Wahba SL, El Sayed MH, Roushdy AM. Immediate- and Short-Term Effect of Percutaneous Patent Ductus Arteriosus Closure on Left Ventricular Function: A Speckle Tracking Echocardiographic Study. J Indian Acad Echocardiogr Cardiovasc Imaging 2020;4:161-7
|How to cite this URL:|
Ezzeldin DA, Wahba SL, El Sayed MH, Roushdy AM. Immediate- and Short-Term Effect of Percutaneous Patent Ductus Arteriosus Closure on Left Ventricular Function: A Speckle Tracking Echocardiographic Study. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2020 [cited 2020 Sep 28];4:161-7. Available from: http://www.jiaecho.org/text.asp?2020/4/2/161/292621
| Introduction|| |
A patent ductus arteriosus (PDA) occurs when the ductus fails to completely close after delivery. PDA occurs commonly in premature infants, especially in those with respiratory distress syndrome. In very low birth weight infants (birth weight below 1500 g), the incidence of PDA is about 30%.,
The aim of management in older children is to occlude the PDA to prevent significant increase in pulmonary circulation and the development of pulmonary vascular disease. Occluding the defect also decreases the risk of endocarditis and endarteritis. The timing of closure depends on the size of the defect and the presence of symptoms. In asymptomatic infants, conservative management is possible to allow time for spontaneous closure. In patients with a large PDA and congestive heart failure, the defect must be closed urgently. Transcatheter occlusion has become the treatment of choice for most patients. Surgical closure is performed in cases not amenable to a percutaneous approach, such as young infants with congestive heart failure or pulmonary hypertension. More recently, some centers are using video-assisted thoracoscopic surgery or robotic surgery to assist with the closure.,
Echocardiography is the procedure of choice to confirm the diagnosis. Echocardiogram can define the size of the PDA as well as indirectly assess the degree of shunting by measuring left atrial and left ventricular (LV) dilation. Echocardiography is also employed to rule out associated cardiac lesions.
Early post-PDA closure, LV end-diastolic diameter, and systolic function (ejection fraction [EF] and fractional shortening) improve remarkably usually within 1 month. Cardiac systolic function assessment 1 month post-PDA closure is the same as that of the preclosure status. The explanation for this observation is that PDA is associated with the left-to-right shunt, which increases the LV preload. Based on the Frank Starling's law, increase in preload culminates in augmented contractility (systolic function and EF). PDA closure results in a sudden drop in LV preload and thus a decrease in systolic performance. Another rationale for this observation is sudden increase in afterload, which is due to the termination of blood flow through PDA and the low-resistance pulmonary circulation that contribute to systolic dysfunction.,
Two-dimensional (2D) speckle-tracking echocardiography has recently emerged as a novel technique for objective and quantitative evaluation of global and regional myocardial function, independent of the angle of myocardial insonation., The main advantages include providing an insight into regional and global myocardial deformation as well as detecting subtle myocardial changes that are not detected using the usual 2D parameters. This made the idea of studying the LV deformation pre and post-PDA closure appealing.
| Methods|| |
The study included 45 patients with PDA who were referred for elective trans-catheter PDA closure in Ain Shams University Hospital from November 2016 to July 2017. LV function evaluation by speckle tracking echocardiography (STE) was done. Only 36 patients were compliant to follow-up and were accepted by the software for regional analysis.
Prior to trans-catheter closure, all patients were subjected to the following: history taking, clinical examination, routine investigations, Chest X-ray, ECG, and transthoracic echocardiography.
Conventional two-dimensional echocardiography
Standard 2D echocardiogram was performed using Philips IE 33X matrix 3D echocardiography machine, Australia.
In agitated infants and children, sedation with chloral hydrate aqueous solution (50 mg/kg) 15 min prior to the study was done.
A phased-array S8-3 pediatric probe with frequency range from 8 to 3 MHz was used for infants below 1 year, and a phased-array S5-1 probe with frequency range from 5 to 1 MHz was used for infants older than 1 year and children.,
Echocardiographic assessment Preclosure, immediately after closure, and at 1 month follow-up
- The LV dimensions and functions were assessed using the Teichholz method. The M-mode was used to estimate the LV end-diastolic dimension (EDD) and LV end-systolic dimension (ESD) by applying the m-mode to the LV just below the mitral valve in a parasternal long-axis view. LV volumes were measured in the apical four-chamber view
- PDA assessment: The assessment of the PDA was done to evaluate the site and shape of the ductus and assess the diameter of the ampulla and the pulmonary end as well as the length of the duct.,
Speckle tracking echocardiography
Images were acquired during breath holds with stable electrocardiographic recordings and ECG gated, digitally stored for offline analysis. At least three cycles were stored in order to perform offline STE analysis.
The LV was imaged in the apical four-chamber view; the conventional 2D echocardiographic gray-scale apical four-chamber images were recorded. An optimal frame rate of 60–80 frames per se cond was obtained by adjusting the sector width and depth of the image to focus on the LV.
Methods of analysis
Analysis was done offline using the Q-lab software, and quantification system was done mostly on the echocardiography machine and rarely on the workstation.
The following methods were used for analysis:
All echocardiographic studies were recorded, and then longitudinal strain for the LV was obtained for subsequent offline analysis using the software.
LV strain was analyzed using the conventional 2D echocardiographic gray-scale apical four-chamber images. The region of interest was obtained by tracing the LV endocardial borders at the level of the septum and the free wall in a still frame at end systole. An automated software program was used to calculate the frame-to-frame displacements of speckle pattern within the region of interest throughout the cardiac cycle.,
Longitudinal strain [Figure 1] and strain rate [Figure 2] curves were obtained for 16 LV segments (the basal, mid, and apical segments of the LV free wall and septum and the apex), and the global LV strain curve was based on the average of the 16 regional strains. The extent of myocardial deformation (defined as the peak longitudinal systolic strain) was expressed as a percentage of the longitudinal shortening in systole compared with diastole for each segment of interest.,
|Figure 1: Longitudinal strain curves for the seven left ventricular segments and global strain, and time to peak longitudinal systolic strain in case number 22 pre closure|
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|Figure 2: Longitudinal strain rate curves for the seven left ventricular segments and global strain rate in case number 34 immediately post closure|
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The temporal pattern of LV mechanical contraction was evaluated as the time needed to reach peak strain (time to peak longitudinal systolic strain) using the beginning of the QRS complex as a reference point.
All data were gathered, statistically analyzed, and tabulated. All numerical variables were expressed as mean ± standard deviation, and categorical variables were expressed as percentage (%). Changes in continuous variables were evaluated with the paired t-test. Linear regression analysis was employed for the assessment of correlations between continuous variables. For all analyses, P < 0.05 was considered statistically significant.
| Results|| |
The study patients comprised 25 females (69.4%) and 11 males (30.6%), with a mean age of 4.667 years ranging from 5 months to 21 years.
The patient's body surface area ranged from 0.240 to 1.710 with a mean body surface area of 0.836.
The PDA size of the patients ranged from 0.145 to 0.819 cm with a mean of 0.278 cm.
Two-dimensional and Doppler echocardiographic assessment before and immediately after patent ductus arteriosus closure
Regarding ventricular dimensions, both LV EDD and the LV ESD showed a decrease immediately after PDA closure, however this decrease was statistically insignificant [Table 1].
|Table 1: Comparison between different parameters measured before and after patent ductus arteriosus closure|
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The LV volumes decreased as well, however it took 1 month for this decrease to be statistically significant. The drop in the LV end-systolic volume (ESV) was still insignificant after 1 month, but the LV end-diastolic volume (EDV) drop was significant. The LV EDV index decreased from 54.827 ± 31.5129/m2 at baseline to 46.242 ± 21.4487/m2 1 month after PDA closure [Table 2].
|Table 2: Comparison between different parameters measured before and 1 month after patent ductus arteriosus closure|
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The LV EF decreased after PDA closure, however this decrease was not statistically significant.
Out of 39 patients, 92.3% (36 patients) were properly analyzed by the STE software where only three patients were rejected by the software in the follow-up and were not analyzed.
Speckle tracking echocardiography parameters in patients' prepatent ductus arteriosus closure and immediately after patent ductus arteriosus closure
As for the global strain, the global LV strain decreased after PDA closure from −22.944% ± 3.5128% to −22.028% ± 2.8932%, and this decrease was statistically nonsignificant with P > 0.05
The global LV strain rate decreased immediately after PDA closure from − 1.110% ± 0.2985% to − 1.020% ± 0.3391%, and this decrease was statistically nonsignificant with P > 0.05.
Speckle tracking echocardiography parameters in patients' prepatent ductus arteriosus closure and one month after patent ductus arteriosus closure
Global left ventricular strain
The global LV strain increased after PDA closure from −22.944% ± 3.5128% to −23.444% ± 2.9418%, and this increase was statistically nonsignificant with P > 0.05.
Segmental and global left ventricular strain rate
- Segmental strain rate showed no significant difference between measurements obtained at baseline and those 1-month post-PDA closure
- Global LV strain rate – The global LV strain rate increased 1 month after PDA closure from −1.110% ± 0.2985% to −1.148% ± 0.2927%, and this increase was statistically nonsignificant with P > 0.05.
Segmental and global left ventricular time to peak systolic strain
The regional and global time to peak systolic strain 1 month after PDA closure showed statistically significant increase in almost all segments.
Global left ventricular time to peak systolic strain
The global LV longitudinal time to peak systolic strain increased after PDA closure from 0.646 ± 0.2833 s to 0.765 ± 0.31 s, and this increase was statistically significant with P < 0.05 [Table 3].
|Table 3: The left ventricular segmental and global time to peak systolic strain changes before and 1 month after patent ductus arteriosus closure|
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The heart rate showed a positive correlation with the global strain and a negative correlation with the time to peak systolic strain in patients with PDA preclosure, and these correlations were statistically significant with P = 0.0125 and 0.0517, respectively.
During the immediate follow-up, the heart rate showed a positive correlation with the global strain, strain rate, and the time to peak systolic strain, and these correlations were statistically significant with P = 0.0086, 0.0010, and 0.0248, respectively.
On 1-month follow-up, the heart rate showed a positive correlation with the global strain, strain rate, and time to peak systolic strain, and these correlations were statistically significant with P = 0.0123, 0.0208, and 0.0010, respectively.
| Discussion|| |
The ductus arteriosus (DA) is an essential anatomic conduit in the fetus, connecting the pulmonary artery to the aorta, allowing much of the right ventricular space to bypass the unexpanded lungs. After birth, the DA closes and becomes the ligamentum arteriosum.
Ductus closure is clearly indicated for any child or adult who is symptomatic from significant left-to-right shunting through the PDA. In asymptomatic patients with significant left-to-right shunting resulting in left heart enlargement, closure is indicated to minimize the risk of complications in future. Trans-catheter PDA closure is a well-established, safe, and effective procedure. It has become the treatment of choice, with closure rate exceeding 90%–95%.
Theoretically, PDA closure is expected to alter the LV volume overload and remodeling with improvement of systolic and diastolic heart function gradually. However, some reports demonstrate an immediate deterioration in LV systolic performance, which recovers within a few months. This study was conducted to evaluate the LV systolic function before and after PDA closure using the conventional 2D and speckle-derived strain echocardiography. Previously published studies have demonstrated acceptable accuracy and reliability of tissue Doppler imaging and STE modalities in assessing regional myocardial function in children and adults.
The present study included 45 patients with PDA who were referred for PDA trans-catheter closure in Ain Shams University. Out of these 45 patients, only 39 patients were compliant to the follow-up echocardiography. Out of these 39 patients, only 36 patients were feasible for assessment by the Q-lab software for analysis.
The current study demonstrated an early deterioration of LV function following successful trans-catheter ductal closure, which was subclinical but evident by strain changes; the strain rate changes were statistically nonsignificant.
As regards the LV dimensions and volumes following ductal closure, an immediate significant decrease in both LV EDD and EDV was observed at 24-h follow-up, and this decrease was maintained at follow-up after 1 month. In addition, the LV ESV showed the same sustained decrease post-PDA closure. These findings are concordant with the studies conducted by Agha et al., Amoogzar et al., and El-Khuffash et al. These studies reported that LV EDV decreased significantly immediately postclosure and in the 1-month follow-up, which continued to decrease further at the 6-month follow-up. Based on these data, we postulate that a more significant decrease can be demonstrated in our study group at long-term follow-up periods.,,
The earlier significant change in LV EDV as compared to the change in LV ESV can be explained by an abrupt interruption of pulmonary recirculation following PDA closure, which induces a decrease in LV EDV and unmasks latent myocardial dysfunction.
Regarding the EF, there was a nonsignificant decline at 24 h postclosure. The EF pre closure had a mean of 58.889% ± 7.7416% and decreased in the immediate follow-up to a mean of 56.522% ± 6.8283%. At 1-month follow-up, the EF increased to 60.478% ± 5.9203%. If the decreased LV EDV does not accompany a corresponding decrease in LV ESV, the EF will decrease via several possible mechanisms including decreased myocardial contractility or increased afterload, and this is what happened in our study.,
Our findings are in accordance with the previously published data on pediatric patients. These changes could be explained by the fact that PDA is associated with the left-to-right shunt, which increases the LV preload. Based on the Frank–Starling's law, an increase in preload culminates in augmented contractility, whereas PDA closure results in a sudden drop in LV preload and thus a transient decrease in systolic performance.,,, Another rationale for this observation is a sudden increase in the afterload, which is due to the termination of blood flow through PDA and the low-resistance pulmonary circulation that contribute to systolic dysfunction.
Studies done by Amoogzar et al. and Agha et al. showed statistically significant decline in the EF 24–48 h post closure with a statistically significant improvement in the EF 1 month post closure. The statistically nonsignificant decline in our study 24 h post closure can be explained by the fact that most of our patients had a small-to–moderate-sized PDA and only one patient had a large ductus. The mean diameter of the PDA among the patients included in our study was 0.28 ± 0.11, which was considerably less than that of the study groups in other studies.,
Tilahun et al. published a case study on an adult patient who had transient LV dysfunction after PDA closure, who also had a bicuspid aortic valve, which affected the LV volumes. The authors concluded that transient LV dysfunction following PDA closure was found to be associated with large PDA, large amount of shunting, presence of high pulmonary hypertension or low EF prior to PDA closure, and an increased age of patients. Furthermore, the presence of anomalies associated with PDA, such as mitral regurgitation or aortic coarctation, has been reported to be a risk factor that can provoke or deteriorate LV dysfunction following PDA closure.
In the current study, we evaluated LV strain before PDA closure as well as 1 day and 1 month post closure. We used the LV strain as a surrogate for LV subclinical function. Our assumption was based on the fact that LV strain should follow the same pattern of change in EF post-PDA closure. There are only very few studies assessing LV strain pre- and post-closure of left-to-right shunts. One study assessed LV longitudinal strain pre- and post-PDA ligation in preterm babies. Global and segmental longitudinal strain measures reduced statistically significantly early after PDA closure (P < 0.05), but they improved remarkably in the subsequent month.
Our study demonstrated a decrease in the global longitudinal strain as well as the regional segmental strain immediately after PDA closure, which almost regained its baseline values 1 month post-PDA closure. The global longitudinal strain values decreased slightly immediately after closure from a mean of −22.944% ± 3.5128% and before the duct closure to a mean of −22.028% ± 2.8932%, but 1 month after closure, the global longitudinal strain improved from a mean of −22.944% ± 3.5128% to a mean of −23.444% ± 2.9418%. Although the changes in LV deformation in our study followed the same pattern as demonstrated by Amoogzar et al. and Agha et al., the changes in our study unlike other studies were nonsignificant.
It is assumed that a larger LV deforms less with lower strain values to generate the same LV output. Moreover, with a greater stroke volume and a higher output state, strain values were highest in preclosure time and decreased in early postclosure in parallel to the deterioration of LV systolic function.
The changes in global longitudinal strain in our study can be explained by the fact that all our patients had small-to-moderate-sized ductus with a mean of 0.278 ± 0.1158 cm, causing mild LV volume overload. We also demonstrated a significant positive correlation between the PDA size and both LV EDV and ESV. In the study by Amoogzar et al., the patients had a mean PDA diameter of 0.36 ± 0.08 cm, whereas in the study conducted by Agha et al., the patients had a PDA diameter with a mean of 0.311 ± 0.099 cm. This means that the volume overload caused in our study population was less than that caused by larger ducts.
Another hypothesis for the difference in these results could be the fact that in several published studies such as that by Agha et al., the global strain values calculated were based on only six segments unlike our study in which we analyzed the complete LV 16-segment model.
The mean heart rate of the patients included in our study was 122 and 113 bpm in the preclosure, immediate follow-up, and after 1 month. Amoogzar et al. and Agha et al. did not report the mean heart rate of their patients. We postulate that the faster the heart rates, the more technically challenging for the software to track the different myocardial segments throughout the cardiac cycle. We could also demonstrate a statistically significant positive correlation between the heart rate and the global strain values. This correlation was maintained before closure of the duct, immediately after, and in the 1-month follow-up. The higher the heart rate, the less negative the global longitudinal strain values, which may be due to the improper myocardial tracking with faster heart rate.
In the current study, we assessed the strain rate values as well, which followed the same pattern as that of the LV strain. The strain rate values showed a mean of −1.110% ± 0.2985% before closure of the duct. These values decreased in the immediate follow-up to a mean of −1.020% ± 0.3391% and then improved in the 1-month follow-up to a mean −1.148% ± 0.2927%.
Both the global strain values and the global strain rate values decreased immediately after PDA closure, however, the decline in the global strain rate values was less than the decline in global strain values, and this can be explained by the fact that strain rate measurements are technically more difficult and are highly frame rate dependent. In preterm infants with greater heart rates, assessment of strain rate is technically challenging.
To the best of our knowledge, the time to peak systolic strain was never studied as a separate predictor of myocardial systolic function, with no insight into its changes with volume overload and sudden preload reduction. The global time to peak systolic strain increased immediately after the PDA closure in comparison to the preductal closure values, from a mean of 0.646 ± 0.2833 s to a mean of mean 0.706 ± 0.3199 s, but this increase was statistically nonsignificant. The global time to peak strain increased further at 1-month follow-up to 0.765 ± 0.31 s, and this increase was statistically significant with P = 0.04.
The heart rate showed sustained significant inverse correlation with the global time to peak systolic strain in the pre, 1 day, and 1 month post-PDA closure. Whether this should be the only explanation of the significant increase in the time to peak strain 1 month post closure or the time to peak strain reflects an earlier change in LV deformation noted before further significant change in the LV global strain should be an area of active research in future.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]