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. 2012 Aug 15;8(4):375-80.
doi: 10.5664/jcsm.2026.

PFO and right-to-left shunting in patients with obstructive sleep apnea

Marina Guchlerner  1 , Peter Kardos, Eva Liss-Koch, Jennifer Franke, Nina Wunderlich, Stefan Bertog, Horst Sievert
Affiliations

PFO and right-to-left shunting in patients with obstructive sleep apnea

Marina Guchlerner et al. J Clin Sleep Med. .

Abstract

Background: Patent foramen ovale (PFO) with right-to-left shunt has a prevalence of 10% to 34% in the general population. It can cause an ischemic stroke, transient ischemic attack, and paradoxical peripheral or coronary embolization. Its influence on migraine and several other diseases and conditions is currently under debate. Attention has recently been turned to the correlation between PFO and obstructive sleep apnea. Thus far, studies on the prevalence of right-to-left shunts as a surrogate for PFO in these patients were limited by small sample sizes and the results have been conflicting. Here, we evaluate the prevalence of right-to-left shunting (RLS) through transcranial Doppler ultrasound (TCD) in a large patient group with obstructive sleep apnea (OSA).

Methods: One hundred consecutive patients (mean age 59.5 y) with OSA underwent TCD with intravenous injection of agitated saline. The grading of right-to-left-shunts was in accordance with the Spencer PFO Grading Scale.

Results: RLS was detected in 72 of 100 patients (72%). Thirty-four out of these 72 patients (47%) had a shunt grade I or II; 15 (21%) had a shunt Grade III or IV; and 23 (32%) had a large shunt (Grade V or V+). In 47 of 72 patients (65%), a right-to-left shunt was detectable at rest without Valsalva maneuver.

Conclusion: The prevalence of a RLS in patients with OSA is high. Provided other intracardiac or pulmonary shunts were absent, the high prevalence of a RLS suggests a high prevalence of PFO in patients with OSA.

Keywords: Obstructive sleep apnea; patent foramen ovale; right-to-left-shunt; transcranial doppler.

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Figures

Figure 1A
Figure 1A. ST3 Digital Transcranial Doppler System Model PMD 150; divided display: power M-Mode (upper part), spectrogram (lower part); One microembolic signal (MES)
1B
1B. Curtain pattern: uncountable MES; Shunt grade V+
See this image and copyright information in PMC

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