COVID-19 and PFO Test

In the course of the Corona pandemic, studies1 revealed that the SARS-CoV-2 virus causes changes in and around the human vasculature that can be diagnosed by standardized examination methods of Transcranial Doppler Sonography. Ischemic strokes and, in particular, occlusion of large vessels are now well-known neurological sequelae. Due to hypercoagulation, COVID-19 disease can dramatically increase the risk of stroke. In her recent study2, Dr. Wendy Ziai of John Hopkins Hospital in Baltimore/USA addressed the question of whether transcranial Doppler sonography is suitable for detecting microemboli and clinically relevant changes in cerebral blood flow velocity.

Patients with confirmed corona infection underwent approximately 15-minute bilateral Doppler monitoring and emboli detection. The examination was performed approximately 2-5 days after hospital admission. Due to the short observation time and also the small number of patients examined, no emboli were detected. However, this cohort showed that lower than expected CBFVs were observed in critically ill patients with COVID-19 infection. Therefore, Dr. Ziai still considers TCD to be an important tool for diagnosis, as critically ill patients with COVID-19 disease could not be transported. TCD is portable, flexible, and can detect emboli, thus investigating possible stroke mechanisms.

In her conclusion, Dr. Ziai points out that TCD provides clinically useful mechanisms underlying the neurological consequences of COVID-19. It is recommended that future transcranial Doppler studies in COVID-19 patients be supplemented with at least 30 minutes of bilateral emboli detection and bubble (PFO) testing.
Another study3 published in the American Journal of Respiratory and Critical Care Medicine aims to differentiate between common ARDS and COVID-19-induced pulmonary problems. Here, the PFO test was performed to look for related vascular pathophysiologies.