Comparison of Transthoracic Echocardiography, Transesophageal Echocardiography, and Transcranial Doppler in the Detection of Patent Foramen Ovale as the Etiology for Cryptogenic Stroke

Abstract

Cerebral vascular accident, or stroke, is the second leading cause of death worldwide and a common cause of longterm disability. 1 The incidence worldwide is 258/100,000 persons with wide variations between high-and lowincome economies. 2 In the United States, the Centers for Disease Control and Prevention reports stroke affects 795,000 individuals each year, is the fifth leading cause of death, 3 and is the leading cause of long-term disability. 3,4 Between 80% and 87% of strokes are classified as ischemic with cardioembolism, large vessel atherosclerotic disease, and small vessel occlusive disease as the most common causes. 5 The category of cryptogenic stroke is used when the stroke is believed to be ischemic, but there is no identifiable cause. 6 Cryptogenic strokes are believed to be caused by emboli when they do not present as a lacunar infarct on imaging, there is a lack of extracranial atherosclerosis causing greater than 50% stenosis, and other embolic risk factors such as intracardiac thrombus, cardiac tumors, or valvular vegetations are not present. 6,7 Cryptogenic strokes are believed to comprise 25% to 40% of all embolic strokes. 8 When an embolic source for stroke cannot be clearly identified, atrial septal abnormalities such as atrial septal defects and pulmonary shunts are considered potential causes. An atrial septal defect (ASD) is a defect of the 816983J DMXXX10.1177/8756479318816983Journal of Diagnostic Medical SonographyStafford et al.

Overcoming a stubborn patent foramen ovale

“…Time delay to bubble visualization is often used to differentiate between PFO and PAVM on TTE, but this is met with its own limitations in reliability. However, TEE provides superior visualization of the interatrial septum, and direct visualization is possible to differentiate the two 8 . Furthermore, transcranial doppler (TCD) imaging is an emerging modality in the detection of PFO, with sensitivity and specificity often surpassing that of TTE and TEE 8,9 .…”

Loss of vision after transurethral resection of prostate: A case report

“…The foramen oval flap is fused in 75% of children by the age of two, whereas the remaining 25% have a PFO for the rest of their life. 3 , 5 Although most individuals with PFO remain asymptomatic, it is a potential pathway for paradoxical emboli from the venous system to the systemic circulation, whereas in about 40–50% of cases with paradoxical emboli a patent foramen ovale is diagnosed. 4 Paradoxical emboli start with thrombi formation in the lower extremities, venous system and occasionally the pelvic veins, which transfer through the patent foramen ovale (PFO) or other right to left communications and enter into the systemic circulation; they may lead to stroke or peripheral emboli.…”

“… 4 Paradoxical emboli start with thrombi formation in the lower extremities, venous system and occasionally the pelvic veins, which transfer through the patent foramen ovale (PFO) or other right to left communications and enter into the systemic circulation; they may lead to stroke or peripheral emboli. 5 …”

“…Transthoracic echocardiography has a reported sensitivity ranging from 32% to 100%, specificity from 55% to 97% and false-negative findings ranging from 18% to 43%. 5 …”

Secondary stroke prevention in patients with patent foramen ovale

“…Transesophageal echocardiographic (TEE) evaluation in patients with cryptogenic strokes is paramount to making the correct diagnosis and determining the optimal management. The sensitivity of transthoracic echocardiography (TTE) for PFO detection ranges from 32 to 100% [11], but comparison studies between TTE and both TEE or transcranial Doppler ultrasound suggest that the latter two are more sensitive [12,13]. Our practice is to screen patients with TTE and bubble study, and in patients with cryptogenic strokes who would likely be eligible for PFO closure, to perform TEE if the initial TTE was negative.…”