[Postural effect in patients with patent foramen ovale: evaluation of right-to-left shunt with transcranial Doppler and transthoracic echocardiography and correlation with arterial oxygen saturation]. / L'effetto della postura nei pazienti con forame ovale pervio: valutazione dello shunt destro-sinistro con Doppler transcranico ed ecocardiografia transtoracica e correlazione con la saturazione arteriosa di ossigeno.

BACKGROUND: Transcranial Doppler echocardiography and transthoracic echocardiography may detect with high accuracy right-to-left shunt (RLS) due to patent foramen ovale (PFO). However, a standardized diagnostic protocol has never been established. It has been suggested that standing or sitting positions may improve sensitivity of transcranial Doppler due to increased LRS in such positions. We aimed to test efficacy of the sitting position in addition to the supine position in the grading of RLS in patients with PFO. We have also evaluated whether an increase in RLS is associated with a fall in oxygen saturation (SaO2). METHODS: From September 2015 to February 2016, 70 consecutive patients with suspected PFO underwent transcranial Doppler echocardiography and transthoracic echocardiography with microbubble count and evaluation of SaO2. RESULTS: RLS due to PFO was diagnosed in 58 patients (82.9%). An increase in RLS grade in the sitting position was observed in 28 out of 58 patients (48.3%) (group 1), whereas no increase was detected in 30 patients (51.7%) (group 2). Among the clinical and echocardiographic variables considered, group 1 and group 2 differed only in the prevalence of atrial septal aneurysm (35.7 vs 3.3%, p=0.002). Postural changes were not associated with a fall in SaO2. CONCLUSIONS: RLS increases in about half of patients with PFO in the sitting position compared with the supine position, whereas no changes occur in SaO2.

Relationship of resting hemoglobin concentration to peak oxygen uptake in heart failure patients.

Anemia is frequent in chronic heart failure (HF). To calculate what change in peak oxygen uptake ( VO(2)) should be expected in the event of changes in hemoglobin concentration, we studied the correlation between peak VO(2) and hemoglobin concentration in a large HF population. We carried out retrospective analysis of all cardiopulmonary exercise tests (CPET) performed in our HF Clinic between June 2001 and March 2009 in HF patients who had a resting hemoglobin concentration measurement taken within 7 days of the CPET. We collected 967 CPETs, 704 tests were considered maximal and analyzed. We identified 181 patients (26%) as anemic. Peak VO(2) was lower (P < 0.001) in anemic patients (971 +/- 23 ml/min) compared with nonanemic (1243 +/- 18 ml/min). The slope of the VO(2) vs. hemoglobin ratio was 109 ml/min/g/dl at peak exercise. This correlation remained significant also when several confounding variables were analyzed by multivariate analysis. As an average, each gram of hemoglobin accounts, at peak exercise, for 109 ml/min change in VO(2) which is equivalent to 0.97 ml/min/kg. Therefore, in HF patients anemia treatment should increase VO(2) by 109 ml/min for each g/dl of hemoglobin increase.