Journal of Invasive Cardiology

Discussion

Percutaneous transcatheter PFO closure has become a widespread procedure for the prevention of recurrent paradoxical emboli.1 Various types of devices have been used for transcatheter PFO occlusion. All of them are metal-containing foreign bodies which are implanted in the interatrial septum. Postmortem and animal studies have shown good incorporation and complete endothelialization of the devices during the first postprocedural months,³ but it was not clear whether PFO occluders affected the function of structurally normal human hearts. Conventional 2-dimensional and Doppler echocardiography may detect pericardial effusion, valve dysfunction or other obvious mechanical complications of percutaneous PFO closure. In our study group, the analysis of the mitral valve inflow Doppler pattern, which was performed during echocardiographic follow up, revealed a mild, but statistically significant, shortening of the E-wave deceleration time (from 190 ± 29 to 174 ± 16 milliseconds; p = 0.05), reflecting minor changes in diastolic LV function.
The TDI allows for the detection of changes in regional myocardial motion. This method is widely used in the evaluation of diastolic ventricular function.⁴ We used the TDI for the detection of changes in myocardial motion before and following device implantation. The TDI analysis was performed in regions that are anatomically closed to the implanted device: the basal interventricular septum, mitral annulus-LV free-wall attachment and the tricuspid annulus-RV free-wall attachment. The analysis performed showed a reduction in the systolic motion velocity of the basal interventricular septum from 7.6 ± 1.8 to 6.4 ± 2.0 (p = 0.03), without changes in diastolic velocities. No changes in the systolic and diastolic velocities of the free-wall mitral annulus junction or the free-wall tricuspid annulus junction were observed.
The Tei index, which represents the sum of the isovolumic relaxation time and the isovolumic contraction time, divided by the LV ejection time, has been used as a sensitive measure of LV performance, including systolic and diastolic function.⁵ In our study group, the Tei index remained unchanged by consecutive measurements, reflecting the lack of influence of PFO occluding device closure on global myocardial performance. The described changes represent minor echocardiographic findings and are without clinical impact in our patients. These minor alterations were observed at the basal interventricular septum, which is the nearest point of investigation to the occlusive device.