Patent Foramen Ovale-Assessment and Treatment

Highs and lows of hyperoxia: physiological, performance, and clinical aspects

Molecular oxygen (O₂) is a vital element in human survival and plays a major role in a diverse range of biological and physiological processes. Although normobaric hyperoxia can increase arterial oxygen content ([Formula: see text]), it also causes vasoconstriction and hence reduces O₂ delivery in various vascular beds, including the heart, skeletal muscle, and brain. Thus, a seemingly paradoxical situation exists in which the administration of oxygen may place tissues at increased risk of hypoxic stress. Nevertheless, with various degrees of effectiveness, and not without consequences, supplemental oxygen is used clinically in an attempt to correct tissue hypoxia (e.g., brain ischemia, traumatic brain injury, carbon monoxide poisoning, etc.) and chronic hypoxemia (e.g., severe COPD, etc.) and to help with wound healing, necrosis, or reperfusion injuries (e.g., compromised grafts). Hyperoxia has also been used liberally by athletes in a belief that it offers performance-enhancing benefits; such benefits also extend to hypoxemic patients both at rest and during rehabilitation. This review aims to provide a comprehensive overview of the effects of hyperoxia in humans from the "bench to bedside." The first section will focus on the basic physiological principles of partial pressure of arterial O₂, [Formula: see text], and barometric pressure and how these changes lead to variation in regional O₂ delivery. This review provides an overview of the evidence for and against the use of hyperoxia as an aid to enhance physical performance. The final section addresses pathophysiological concepts, clinical studies, and implications for therapy. The potential of O₂ toxicity and future research directions are also considered.

Usefulness of Direct Oral Anticoagulants in Adult Congenital Heart Disease

As thromboembolic events (TEE) are common in adults with congenital heart disease (ACHD), adequate oral anticoagulation for prophylaxis or treatment of TEE is important. Until now, mainly vitamin K antagonists have been used in these patients. The purpose of this study was to provide first data on the use of direct oral anticoagulants in ACHD. This prospective, observational, and longitudinal study included 102 consecutive ACHD, of whom 75 (37 women and 38 men; mean age 50 ± 13 years) could be analyzed. Most common CHD were pre-tricuspid shunts (n = 31; 41%), complex CHD (n = 16; 21%), left heart/aortic valve anomalies (n = 5; 6%), right-sided cardiac/pulmonary artery anomalies (n = 9; 13%), post-tricuspid shunts (n = 3; 4%), and others (n = 11; 15%). Five patients had cyanosis and 3 patients a Fontan circulation. Mean follow-up was 12 ± 11 months. Rivaroxaban was administered in 55 patients, apixaban in 13 and dabigatran in 7 patients for TEE prophylaxis in atrial arrhythmias (n = 57), stroke/transient ischemic attacks (n = 11), deep vein thrombosis (n = 4), pulmonary embolism (n = 1) and atrial thrombi (n = 3). Some patients had >1 indication for adequate oral anticoagulation. CHA2-DS2-VASc score was ≥ 2 in 23 (31%), and 9 (12%) had a HAS-BLED score ≥ 2. There were neither thrombotic or major bleeding events nor major side effects. In conclusion, direct oral anticoagulants appear to be safe and effective in ACHD. Long-term follow-up is needed to substantiate these findings.

Patent foramen ovale in liver transplant recipients does not negatively impact short-term outcomes

AIM

Patent foramen ovale (PFO) is a common atrial septal defect that is largely asymptomatic and often undiagnosed. The impact of a PFO in patients undergoing liver transplantation (LT) is unknown.

OBJECTIVE

Assess the impact of PFO and physiologic intrapulmonary shunt (IPS) on the perioperative outcomes of patients who underwent LT.

METHODS

We performed a retrospective, intention-to-treat analysis of patients with PFO and controls without PFO who underwent LT at Mayo Clinic in Florida between 2008 and 2013. Patients with physiologic IPS were also analyzed. The cohorts were compared for baseline characteristics, length of stay in the intensive care unit (ICU), postoperative oxygen requirements, 30-d cerebrovascular accidents, and mortality.

RESULTS

Of the 935 patients who underwent LT, 10.4% had proven PFO by pre-LT echocardiogram. Control patients (n = 101) were statistically older than PFO and IPS (n = 56) patients, but similar in sex, BMI, Model for End-stage Liver Disease score, American Society of Anesthesiologist score, and left ventricular ejection fraction. PFO and IPS patients had similar length of stay in the ICU, mechanical ventilation times, post-LT oxygen requirements, and 30-d mortality compared to controls. Subgroup analysis showed similar outcomes for large PFO and IPS patients to controls.

CONCLUSIONS

The presence of PFO did not have a negative impact on perioperative LT outcomes.

Acute venous thromboembolic disease and paradoxical embolism

BACKGROUND

We report two cases of paradoxical cerebral embolism associated with acute venous thromboembolic disease.

CASE REPORT

The first case corresponds to a 49-year-old woman with sudden onset of dyspnea and syncope, followed by right upper extremity paresis, aphasia and dysarthria. The admission brain computed tomography (CT) was unremarkable, but lung CT showed multilobar and multisegmentary pulmonary embolism. Echocardiography showed dilated right ventricle with impaired systolic function, moderate tricuspid regurgitation, moderate pulmonary hypertension and positive bubble test, suggestive of a patent foramen ovale (PFO) which was successfully closed by endovascular Amplatzer device placement. The patient was discharged with anticoagulation therapy and permanent antiplatelet aggregation therapy. The second case is a 60-year-old woman found unconscious. Neurological examination revealed expressive aphasia, right hemianopsia, right central facial paralysis and right-sided paresis with a National institute of Health Stroke Scale of 19. Brain CT showed signs of acute left middle cerebral artery infarction. Later, she developed greater impairment of consciousness. A new brain CT showed significant edema with mass effect requiring a decompressive craniotomy. Echocardiography showed PFO and lower extremities' Doppler ultrasound showed a left infrapopliteal posterior tibial right deep venous thrombosis. An inferior vena cava filter was placed and two days after surgery, anticoagulation was started.

Transcatheter treatment of patent foramen ovale combined with abnormal drainage of left superior vena cava to left upper pulmonary vein

Patent foramen ovale (PFO) has been known to be the cause of transient ischemic attacks or stroke, and transcatheter device closure has been the treatment of choice for these defects. Combined defect of abnormal drainage of left superior vena cava (LSVC) to left superior pulmonary vein (LSPV) in PFO patients is an uncommon combination, and both can act as a pathway for paradoxical embolism. We report a successful closure of PFO, using Amplatzer® PFO occluder (St. Jude Medical, St. Paul, MN, USA) and persistent LSVC connected to LSPV using an Amplatzer® Vascular Plug II (St. Jude Medical, St. Paul, MN, USA). Because this combined anomaly of PFO and persistent LSVC can be treated by a single transcatheter intervention, if clinically suspected, a complete evaluation for this anomaly should be considered.

Massive pulmonary thromboembolism after intravenous stroke thrombolysis

The authors present a 76-year-old female with high blood pressure and hypercholesterolaemia as cerebrovascular risk factors, who received intravenous thrombolysis for an ischaemic stroke with a progressive neurological improvement. She was asymptomatic at 48 h and she was transferred to the neurology department where antithrombotic treatment was initiated. She began to sit the following day when she suffered a massive pulmonary embolism (PE). Cardiological study showed patent foramen oval persistence and the presence of an atrial septa aneurysm, and paroxysmal atrial fibrillation. The delay of the onset of the antithrombotic treatment could have been determinant for the massive PE. Thromboembolic complications may be seen after intravenous thrombolysis for ischaemic stroke. An accurate treatment is needed in order to avoid potentially threatening complications such as massive PE.