Platypnea-Orthodeoxia Syndrome: Two Case Reports.

Described for the first time in the middle of the last century, platypnea-orthodeoxia syndrome (POS) is an uncommon condition of positional dyspnea and hypoxemia, triggered by standing and relieved with recumbency. It is most commonly associated with right-to-left shunting through a patent foramen ovale (PFO) or atrial septal defect, however its pathophysiology is not entirely understood. As a rare syndrome, it remains underdiagnosed in many patients. We report two different cases that illustrate the challenge of this diagnosis and therapeutic approach. In the first case, a transesophageal echocardiogram (TEE) showed interatrial communication, ostium secundum type, with bidirectional shunting. Patient underwent a successful percutaneous closure of communication, with no residual shunting and clinical improvement and no positional hypoxemia. In the second case, infectious complications were the cause of hemodynamic changes producing meaningful right-to-left pressure gradients, resulting in POS. After antibiotic treatment there was a major clinical improvement and a second TEE showed bidirectional shunting with no positional variation. It was assumed resolution of POS after treatment of infectious complications with no need for immediate surgery. These two cases, with very distinctive functional and anatomic components, illustrate the challenge of understanding the exact mechanism by which POS results in clinical symptoms. A suggestive history and positional variation of oxygen saturation are very useful clues for its diagnosis in cases of unexplained hypoxemia.

Hypocalcaemia in an adult: the importance of not overlooking the cause.

A 58-year-old male patient was admitted at the São Bernardos's Hospital (Setúbal, Portugal) with generalised muscle spasms, dyspnoea, laryngospasm and bronchospasm in the context of severe hypocalcaemia. Despite efforts to correct serum calcium, it remained below average, leading to question the true cause of hypocalcaemia. Low parathyroid hormone and 25-hydroxyvitamin D, along with facial anomalies, palate defect and cognitive impairment with concomitant psychiatric disorder led to a suspicion of a DiGeorge/velocardiofacial/22q11.2 deletion syndrome (DS), which was confirmed through genetic testing. The 22q11.2 DS has a wide phenotypic expression and there are growing reports of diagnosis being made in adulthood. This case report highlights the importance of understanding the cause of refractory hypocalcaemia and alerts medical community to carefully access these patients, for this metabolic disorder may only present in later stages of life.