Extracerebral paradoxical embolisms in patients with intracardiac shunts

Abstract 

Background

Intracardiac shunts are considered to play a role in cryptogenic ischemic stroke. However, data on paradoxical embolization into the peripheral arteries remains scarce. Since passage of the emboli through an intracardiac shunt is considered to be the possible etiological mechanism, identification of the presence of a venous thrombus and its migration via the cardiac shunt are essential to confirm this pathogenic mechanism. However, both of these essential components are often difficult to establish due to various methodological and temporal issues.

Methods

Various factors limiting the diagnostic methods of intracardiac shunts are discussed.

Results

The diagnostic criteria for intracardiac shunt should be aimed at looking into both cerebral as well as peripheral arterial beds. Utilizing the quantitative grading scales may help in a better assessment of the intracardiac shunts.

Conclusions

Quantification of the intracardiac shunt and its “functional potential” should be considered an individuals' preferential predisposition for the involvement of various arterial beds. This would help in a better understanding of the complex relationship between intracardiac shunts and various systemic embolic phenomena and planning for a definitive treatment.

Keywords: Patent foramen ovale, Transcranial Doppler, Paradoxical embolization