Background:
Postural Orthostatic Tachycardia Syndrome (POTS) is a constellation of signs and symptoms that occurs when the patient stands upright. It affects primarily young women. On the other hand, PFO is a hidden condition that doesn’t cause signs and symptoms in most cases.
Method:
331 POTS patients were randomly selected during the period of June 2014 to April 2016 from our clinic and they underwent PFO test. In addition to that, patients underwent tilt test with SPO2 recordings every 2 minutes until 10 minutes to calculate the change in SpO2 of that period of time.
Results:
Out of 331 patients, 292 patients were females (88%; n=292 age 32.48 ± 10.78), 39 patients were males (12%; n=39 age 28.87 ± 11.69). 136 patients (41%) had no drop in their SPO2 and 17 of 136 patients had positive(+) PFO test (Grade 1 PFO in 4 patients, Grade 2 PFO in 2 patients, Grade 3 PFO in 3 patients and Grade 4 PFO in 8 patients). 77 patients (23%) had a drop of 1% in their SPO2 and 11 of 77 patients had + PFO test (Grade 1 PFO in 3 patients, Grade 2 PFO in 1 patient, Grade 3 PFO in 2 patients and Grade 4 PFO in 5 patients). 46 patients (14%) had a drop of 2% in their SPO2 and 10 of 46 patients had + PFO test (Grade 1 PFO in 2 patients, Grade 3 PFO in 2 patients and Grade 4 PFO in 6 patients). 16 patients (5%) had a drop of 3% in their SPO2 and 3 of 16 patients had + PFO test (Grade 1 PFO in 1 patient, Grade 2 PFO in 1 patient, Grade 3 PFO in 1 patient). 9 patients (3%) had a drop of 4% in their SPO2 and 1 of 9 patients had + PFO test (Grade 2). 5 patients (1.5%) had a drop of 5% in their SPO2 and 2 out of 5 patients had + PFO test (Grade 1 PFO in 1 patient and Grade 4 PFO in 1 patient). 2 patients (0.6%) had a drop of 6% in their SPO2 and both of them had + PFO test (Grade 2 PFO in 1 patient, Grade 4 PFO in 1 patient). 40 patients (12%) had a rise in their SPO2 and 4 of 40 patients had + PFO test (Grade 2 PFO in 2 patients, Grade 3 PFO in 1 patient and Grade 4 PFO 1 patient).
Conclusion:
Our research results demonstrated that 15% of patients with POTS have PFO. Though orthodeoxia is relatively uncommon, this study demonstrated orthodeoxia in 59% of patients. Only 2% patients showed orthodeoxia of >5%, but further studies should be done to define the clinical significance of the study.
How to understand patent foramen ovale clinical significance - Part II: Therapeutic strategies in cryptogenic stroke
