Case of positional dyspnoea and hypoxia secondary to intracardiac shunting

Platypnea-orthodexia syndrome (POS) is a rare but well-characterised condition where hypoxaemia and breathlessness occur while upright but resolve once recumbent. Early recognition can result in excellent outcomes for patients and can prevent unnecessary investigations for patients, especially if they present repeatedly to hospital after missed diagnosis. We present a case of a 75-year-old woman with a chronic history of breathlessness who was picked up after observations at a routine outpatient clinic. Early recognition of the POS allowed for appropriate investigations to take place identifying a patent foramen ovale (PFO). She was referred to the tertiary centre for closure of her PFO with complete resolution of her symptoms.

Platypnoea and orthodeoxia in the hepatopulmonary syndrome

A 71-year-old female patient with alcohol-induced cirrhosis presented with symptoms of dyspnoea. Previous extensive investigations had detected no apparent cause. Platypnoea and orthodeoxia were observed. A bubble echocardiogram revealed significant intracardiac shunting and a diagnosis of hepatopulmonary syndrome was made. The patient was discharged on home oxygen and referred for liver transplantation.

Platypnoea–orthodeoxia syndrome: beware of investigations undertaken supine

Platypnoea–orthodeoxia syndrome (POS) is a rare disorder, manifesting as deoxygenation occurring when the patient is in the upright position. Four broad mechanisms for the condition have been described: intracardiac shunts, intrapulmonary shunts, hepatopulmonary syndrome and pulmonary ventilation–perfusion mismatch. Here, we present the first case of POS in a patient with a proven right to left intracardiac shunt occurring in the context of postural hypotension and normal right heart pressures. We highlight the need to carry out investigations in the upright position before discounting intracardiac shunting as a cause for the syndrome. Short-term improvement of the syndrome was obtained with medical management of the patient’s orthostatic hypotension and as such suggests a conservative management strategy for similar patients, which may delay the need for invasive procedures to close the anatomical defect.

Pacemakers in children and adolescents

Children have been the beneficiaries of pacing therapies since the pioneering days of the technology. Yet, despite the fact that paediatric pacemaker implants represent around 1% of all pacemaker implantations, there are no guidelines at present dedicated to pacing in this population. This chapter discusses the challenges and needs specific to pacing therapy in children, such as the small stature and the continual somatic growth of paediatric patients; the prevalence of intracardiac shunting; and the often complex anatomical heart structures in children with an indication for pacing. Such differences from adult pacemaker recipients are reflected in the decisions on, for example, implantation route (epicardial versus endocardial), on choice of single-chamber versus dual-chamber devices, selection of pacing sites, or programming. The chapter also highlights questions about lead removal, which is particularly important given the sheer number of replacements expected in paediatric patients, and provides an outlook towards the future of pacing in children and the role of leadless devices and future therapeutic advances.

Platypnea-Orthodeoxia Syndrome: To Shunt or Not to Shunt, That is the Question

Platypnea-orthodeoxia syndrome is a rare disease defined by dyspnea and deoxygenation, induced by an upright position, and relieved by recumbency. Causes include shunting through a patent foramen ovale and pulmonary arteriovenous malformations. A 79-year-old woman experienced 2 syncopal episodes at rest and presented at another hospital. In the emergency department, she was hypoxic, needing 6 L/min of oxygen. Her chest radiograph showed nothing unusual. Transthoracic echocardiograms with saline microcavitation evaluation were mildly positive early after agitated-saline administration, suggesting intracardiac shunting. She was then transferred to our center. Right-sided heart catheterization revealed no oximetric evidence of intracardiac shunting while the patient was supine and had a low right atrial pressure. However, her oxygen saturation dropped to 78% when she sat up. Repeat transthoracic echocardiography while sitting revealed a dramatically positive early saline microcavitation-uptake into the left side of the heart. Transesophageal echocardiograms showed a patent foramen ovale, with right-to-left shunting highly dependent upon body position. The patient underwent successful percutaneous patent foramen ovale closure, and her oxygen supplementation was suspended. In patients with unexplained or transient hypoxemia in which a cardiac cause is suspected, it is important to evaluate shunting in both the recumbent and upright positions. In this syndrome, elevated right atrial pressure is not necessary for significant right-to-left shunting. Percutaneous closure, if feasible, is first-line therapy in these patients.