the prevalence of right to left shunt in chronic obstructive pulmonary disease patients with increased pulmonary hypertension

background: one of the important etiologies for cryptogenic stroke is paradoxical embolization secondary to patent foramen ovale (pfo). foramen ovale can secondarily reopen due to pulmonary arterial hypertension (pah) which is common among the older age. pah is known as a frequent and life threatening complication of copd. the aim of this study was to determine the prevalence of pfo between copd patients with pah and compare it with the ratio of pfo in non pah copd patients by valsalva maneuver (vm) following the tcd test.methods: this study was performed on 55 patients with copd exacerbation who were admitted to rasul-akram hospital in tehran, iran. the patients with high pah were considered as the case group and the others without pah were the control group. all patients underwent trascranial doppler (tcd) to detect intracardiac right-to-left shunt (rls) related by pfo. the data were collected and analyzed. results: in the case group, among 45 patients 25 (55.5%) males and 20 (44.5%) females] with the mean age of 64.68±10.73 years, 31 (68.8%) subjects had pfo. in 10 control patients whose pap were normal during tte, we detected pfo in 2 (20%) patients during vm (p<0.001). there was a significant correlation with the number of microembolic signals (mes) and the increase in pap (p=0.019).conclusion: right to left shunting was significantly more frequent in copd patients with high pap. high pulmonary pressure had a cardinal role in increasing the prevalence of rls among these patients.