Unexplained Hypoxemia in a Patient With Transient Ischemic Attack.

CASE PRESENTATION: An 84-year-old woman with a medical history of hypertension, hypothyroidism, and transient ischemic attacks presented with right-sided upper and lower extremity weakness for 1 day. She was a lifetime nonsmoker with no known heart disease or chronic lung disease. She had no occupational exposure or pertinent family history. She denied any fevers, chills, rashes, or shortness of breath. There was no history of recent travel.

A 70-Year-Old Woman With Refractory Hypoxemia.

CASE PRESENTATION: A 70-year-old woman was transferred to our ED from an outside ED for hypoxemia. Three weeks earlier, an inpatient evaluation for syncope revealed a right intraventricular filling defect, multiple pulmonary nodules, pulmonary emboli, and a left breast mass. She underwent breast biopsy, was started on rivaroxaban, and was discharged with outpatient follow-up. She experienced progressively worsening dyspnea, prompting a return to the outside ED, where she was found to be severely hypoxemic and was intubated. Her medical history included diabetes, hypertension, hyperlipidemia, COPD, hypothyroidism, diastolic heart failure, and a 40+ pack-year smoking history.

Cardiac and Echocardiographic Markers in Cryptogenic Stroke with Incidental Patent Foramen Ovale.

OBJECTIVE: Some cardiac abnormalities could be a substrate for potential embolic source in cryptogenic stroke (CS). We evaluated whether cardiac and echocardiographic markers were associated with CS in patients with incidental patent foramen ovale (PFO) as defined using the Risk of Paradoxical Embolism (RoPE) score. MATERIALS AND METHODS: Among 677 patients enrolled in a multicenter observational CS registry, 300 patients (44%) had PFOs detected by transesophageal echocardiography. They were classified into probable PFO-related stroke (RoPE score>6, n = 32) and stroke with incidental PFO (RoPE score≤6, n = 268) groups, and clinical characteristics, laboratory findings, cardiac and echocardiographic markers (i.e. brain natriuretic peptide, left atrial [LA] diameter, ejection fraction, early transmitral flow velocity/early diastolic tissue Doppler imaging velocity [E/e'], LA appendage flow velocity, spontaneous echo contrast, atrial septal aneurysm, substantial PFO, and aortic arch plaques), stroke recurrence, and excellent outcome (modified Rankin scale score <2) at discharge were compared. Risk factors for low RoPE scores were determined using multiple logistic regression analysis. RESULTS: Higher brain natriuretic peptide levels (p = 0.032), LA enlargement (p < 0.001), higher E/e' (p = 0.001), lower LA appendage flow velocity (p < 0.001), non-substantial PFO (p = 0.021), and aortic arch plaques (p = 0.002) were associated with the low RoPE score group. Patients with high RoPE scores had excellent outcomes (58% versus 78%, p = 0.035). LA enlargement (age- and sex-adjusted odds ratio, 1.15; 95 % confidence interval, 1.00-1.32; p = 0.039) was an independent predictor of low RoPE scores. CONCLUSIONS: Abnormal cardiac substrate could be associated with CS occurrence in a subset of patients with PFO. Patients with CS who had incidental PFO may be at risk of cardioembolism.

Patent foramen ovale revealed by COVID-19 pneumonia.

BACKGROUND: Platypnea-orthodeoxia syndrome (POS) is a rare condition characterized by dyspnoea (platypnea) and arterial desaturation in the upright position resolved in the supine position (orthodeoxia). Intracardiac shunt, pulmonary ventilation-perfusion mismatch and others intrapulmonary abnormalities are involved. CASE PRESENTATION: We report a case of POS associated with two pathophysiological issues: one, cardiac POS caused by a patent foramen ovale (PFO) and second, pulmonary POS due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interstitial pneumonia. POS has resolved after recovery of coronavirus disease 2019 (COVID-19) pneumonia. CONCLUSIONS: Right-to-left interatrial shunt and intrapulmonary shunt caused by SARS-CoV-2 pneumonia contributed to refractory hypoxemia and POS. Therefore, in case of COVID-19 patient with unexplained POS, the existence of PFO must be investigated.

The Efficacy of Percutaneous Patent Foramen Ovale Closure on Migraine: a Meta-Analysis of Randomized Controlled Trials and Observational Studies.

OBJECTIVES: Whether patent foramen ovale (PFO) closure is effective on migraine is controversial. This article was aimed at assessing the efficacy of PFO closure on migraine based on randomized controlled trials (RCTs) and observational studies. METHODS: We searched PubMed, Embase, and Cochrane databases up to October 2020 evaluating PFO closure versus control in patients with migraine, then conducted a meta-analysis of all RCTs and observational studies, respectively. The main outcomes were (1) respond rate: complete cessation of migraine; (2) reduction in the frequency of migraine attacks per month; and (3) reduction in migraine days per month. RESULTS: Seven studies (3 RCTs and 4 observational studies), containing 887 migraine patients, were identified. (1) The respond rate of PFO closure on migraine was significantly higher than control group both in RCT subgroup and observational studies subgroup (OR 3.86, 95% CI 1.35-11.04, P = 0.01 in RCTs; OR 8.28, 95% CI 2.31-29.67, P = 0.001 in observational studies). (2) Reduction in frequency of migraine attacks was higher in PFO closure group compared with control group in the RCT subgroup analysis (mean difference (MD) = 0.57, 95% CI 0.23-0.90, P = 0.0009). (3) Reduction in migraine days was also higher in PFO closure group compared with control group in the RCT subgroup analysis (MD = 1.33, 95% CI 0.35-2.31, P = 0.008). CONCLUSIONS: PFO closure might be suitable for migraine patients, especially for migraine with aura, by cessation of migraine headaches or reducing migraine attacks and migraine days.

Stroke and presence of patent foramen ovale in sickle cell disease.

Sickle cell disease (SCD) is an inherited monogenic hemoglobinopathy characterized by formation of sickle erythrocytes under conditions of deoxygenation. Sickle erythrocytes can lead to thrombus formation and vaso-occlusive episodes that may result in hemolytic anemia, pain crisis and multiple organ damage. Moreover, SCD is characterized by endothelial damage, increased inflammatory response, platelet activation and aggravation, and activation of both the intrinsic and the extrinsic coagulation pathways. Cerebrovascular events constitute an important clinical complication of SCD. Children with SCD have a 300-fold higher risk of acute stroke and by the age of 45 about 25% of patients have suffered an overt stoke. Management and prevention of stroke in patients with SCD is not well defined. Moreover, the presence of patent foramen ovale (PFO) increases the risk of the occurrence of an embolic cerebrovascular event. The role of PFO closure and antiplatelet or anticoagulation therapy has not been well investigated. Moreover, during COVID-19 pandemic and taking into account the increased rates of thrombotic events and the difficulties in blood transfusion, management of SCD patients is even more challenging and difficult, since data are scarce regarding stroke occurrence and management in this specific population in the COVID-19 era. This review focuses on pathophysiology of stroke in patients with SCD and possible treatment strategies in the presence of PFO.

Atrial Fibrillation Following Patent Foramen Ovale Closure: Systematic Review and Meta-Analysis of Observational Studies and Clinical Trials.

Background and Purpose: Multiple studies evaluated whether patent foramen ovale (PFO) closure reduces the risk of ischemic stroke. One commonly reported complication of PFO closure is the development of atrial fibrillation (AF), which is itself a powerful stroke risk factor that requires specific management. This study aims to evaluate the frequency of AF in patients post-percutaneous closure of PFO and the clinical factors that predict AF detection. Methods: Studies were identified by systematically searching EMBASE and MEDLINE databases on July 11, 2019. Meta-analysis of proportions was performed, assuming a random-effects model. Results: A total of 6 randomized controlled trials and 26 observational studies were included, comprising 3737 and 9126 patients, respectively. After PFO closure, the rate of AF development was 3.7 patients per 100 patient-years of follow-up (95% CI, 2.6­4.9). The risk of AF development is concentrated in the first 45 days post-procedure (27.2 patients per 100 patient-years [95% CI, 20.1­34.81], compared with 1.3 patients per 100 patient-years [95% CI, 0.3­2.7]) after 45 days. Meta-regression by age suggested that studies with older patients reported higher rate of AF (P=0.001).In medically treated patients, the rate of AF development was 0.1 per 100 patient-years of follow-up (95% CI, 0.0­0.4). Closure of PFO is associated with increased risk of AF compared with medical management (odds ratio, 5.3 [95% CI, 2.5­11.41]; P<0.001). Conclusions: AF is more common in PFO patients who had percutaneous closure compared with those who were medically treated. The risk of AF was higher in the first 45 days post-closure and in studies that included patients with increased age.

Impact of Patent Foramen Ovale Anatomic Features on Right-to-Left Shunt in Patients with Cryptogenic Stroke.

The purpose of this study was to investigate the impact of the morphologic characteristics of patent foramen ovale (PFO) on right-to-left shunt (RLS) in patients with PFO and cryptogenic stroke using transesophageal echocardiography and saline contrast transthoracic echocardiography (c-TTE). Of the 165 patients with PFO stroke, both the height and the length of PFO in the provoked RLS group were smaller than those in the constant RLS group. PFO height, interatrial septum mobility and proportion of atrial septal aneurysms were greater in the severe RLS group than in the mild and moderate RLS groups. Multivariate analysis revealed that PFO height and interatrial septum mobility were independent predictors of severe RLS. Multiple territorial ischemic lesions were more common in the severe RLS or constant RLS group. Our findings indicated that the severity of RLS was related to the anatomic features in PFO, inducing different cerebral ischemia lesion patterns in cryptogenic stroke patients with PFO.

Patent foramen ovale presenting with platypnoea-orthodeoxia syndrome and stroke after multi-organ resection.

Platypnoea-orthodeoxia syndrome (POS) is defined by oxygen desaturation and dyspnoea in upright position that improves by lying down. It results from a right to left shunt at the intracardiac or intrapulmonary level. A 53-year-old ovarian cancer patient presented with POS that was refractory to oxygen therapy. The symptoms began after an extensive abdominal and pelvic surgery as treatment of her cancer with a complex hospital course. A patent foramen ovale was found with the use of transoesophageal echocardiography. A percutaneous closure was done with positive outcome and dyspnoea disappearance. In this case with its challenging clinical setting, we present a unique clinical scenario of an immediate postoperative POS syndrome. We address the different therapeutic modalities and the need for a multidisciplinary medical approach.

Analysis of the characteristics of sleep in patients with patent foramen ovale complicated with obstructive sleep apnea.

PURPOSE: Analyzing sleep quality and sleep structure in patients with patent foramen ovale (PFO) complicated with obstructive sleep apnea (OSA) and the interaction between OSA and PFO in sleep. METHODS: We compared patients with PFO complicated with OSA, patients with simple PFO, and controls. Pittsburgh Sleep Quality Index was used to compare sleep quality and polysomnography was used to compare sleep structure of the three groups. RESULTS: Compared with the control group (n = 62), PFO with OSA (n = 48) and simple PFO (n = 61) groups had more frequent occurrence of poor sleep quality (χ2 = 89.901; p < 0.001). These two groups also showed decreased sleep efficiency (p < 0.010), lower percentages of REM sleep, and reduced N3 sleep (p < 0.050). The N2 sleep was prolonged (p < 0.010). The nocturnal lowest SpO2 was lower and the oxygen desaturation index was higher (p < 0.50). Compared with the simple PFO group, the poor sleep quality was more frequent in the PFO with OSA group; sleep latency (p < 0.001) was prolonged; wake after sleep onset (p < 0.001) and arousal times (p = 0.031) were increased; and sleep micro-arousal index (p = 0.037), periodic leg movement index (p = 0.024), and apnea hypopnea index (p < 0.001) were higher in the PFO with OSA group. CONCLUSION: Patients with PFO and OSA have poor sleep quality with changes in sleep stage and high occurrence rate of sleep disorders. OSA further deteriorates sleep quality and alters sleep structure in patients with PFO.

"One-stop shop": safety and efficacy of combining atrial septal defect occlusion and left atrial appendage closure for patients with atrial septal defect and atrial fibrillation.

BACKGROUND: One-stop occlusion, which is defined as the combination of atrial septal defect [ASD] or patent foramen ovale [PFO] occlusion and left atrial appendage [LAA] closure, in patients with ASD/PFO and atrial fibrillation (AF) has not yet been investigated systematically. This study aimed to evaluate the safety and efficacy of one-stop occlusion in the treatment of adult patients with ASD/PFO and AF. METHODS: Inpatients with AF and ASD/PFO were recruited between August 2014 and April 2019. Preoperatively, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were conducted to identify the ASD/PFO size and margin, presence of thrombus in the LAA, and LAA orifice width and depth at 0°, 45°, 90°, and 135°. After confirmation of the indications of LAA closure (LAAC) and ASD/PFO occlusion, the procedures were performed simultaneously under general anesthesia. Oral anticoagulants were administered for 45-60 days, followed with regular evaluation of TTE and TEE. RESULTS: Forty-nine patients (age, 65.6 ± 9.6 years) were recruited in this study, including 24 patients with ASD and 25 patients with PFO. They were treated with LAAC and ASD/PFO occlusion successfully. The mean ASD size and mean diameter of the ASD occluders were 14.2 ± 7.7 and 25.4 ± 8.5 mm, respectively. The mean PFO size was 3.5 ± 0.4 mm. The mean maximal LAA orifice width and depth were 20.5 ± 3.4 and 28.3 ± 3.6 mm, respectively. All patients were implanted with a Watchman device (diameter, 27.1 ± 2.9 mm). Postoperatively, all patients took anticoagulants orally for 45-60 days, and their mean postoperative follow-up duration was 29.0 ± 12.1 months. Postoperative TEE showed that all had normal positioning of the LAA and ASD/PFO occluders. At 45-60 days after operation, TEE showed that the LAA and ASD/PFO occluder were in the normal position; however, two patients who took warfarin and novel oral anticoagulants, respectively, have developed occluder thrombosis. After adjusted anticoagulant therapy, TEE showed that the thrombus disappeared at 6 months after operation. CONCLUSION: One-stop occlusion is safe and effective for the treatment of adult patients with ASD/PFO and AF. It is also feasible to administer warfarin or novel oral anticoagulants after operation.

Multiple Intracardiac and Paradoxical Thrombi Caused by a Thrombus Entrapped in a Patent Foramen Ovale.

Patent foramen ovale (PFO) usually represents a benign incidental finding. Occasionally, a PFO can open widely, resulting in paradoxical embolism, with potentially devastating consequence. Floating intracardiac thrombi and thrombus straddling a PFO are 2 extremely rare conditions associated with a dismal prognosis and encountered almost exclusively in the setting of pulmonary embolism (PE). We report the unusual case of a 47-year-old man with an unremarkable medical history who presented with a bilateral PE and multiple paradoxical and intracardiac floating thrombi in the setting of a thrombus entrapped in a PFO.

Echocardiographic diagnosis of right-to-left shunt using transoesophageal and transthoracic echocardiography.

BACKGROUND: The diagnosis and quantification of right-to-left shunt (RLS) using transthoracic echocardiography (TTE) as well as transoesophageal echocardiography (TOE) have not been well established. We aimed to diagnose RLS by TOE using direct visualisation of the shunt and to compare the diagnosis with TTE diagnosis using conventional methods. METHODS AND RESULTS: We evaluated 141 patients with ischaemic stroke for RLS by both non-sedation TOE and TTE using saline contrast and Valsalva manoeuvre. The amount (graded as 0 to IV) and timing of RLS were demonstrated. All patients were classified into four groups by TOE based on direct visualisation of shunt through a patent foramen ovale (PFO) or either pulmonary vein: no shunt (group 1: n=11), PFO (group 2: n=47), pulmonary RLS (group 3: n=25) and indeterminate RLS (group 4: n=58). All cases in group 3 showed delayed shunt, and all cases in group 4 had small shunt. On TTE findings, all cases with early appearing large shunt (cardiac cycles ≤3 and shunt grade ≥III) were group 2. Six of the eight patients with delayed appearing large shunt on TTE were group 3. TTE diagnosis of PFO using criteria of cardiac beats ≤3 and grade ≥II had a sensitivity of 85% and a specificity of 98% compared with TOE diagnosis using shunt visualisation. CONCLUSIONS: Compared with TOE using shunt visualisation, TTE accurately diagnosed large PFO using criteria of cardiac cycles ≤3 and shunt grade ≥III. TTE possibly diagnosed pulmonary shunt using criteria of cardiac cycles >3 and shunt grade ≥III. Both modalities showed limitations in diagnosing small amount of RLS.

Impaired pulmonary gas exchange efficiency, but normal pulmonary artery pressure increases, with hypoxia in men and women with a patent foramen ovale.

NEW FINDINGS: What is the central question of this study? Do individuals with a patent foramen ovale (PFO+ ) have a larger alveolar-to-arterial difference in PO2 ( A-aDO2 ) than those without (PFO- ) and/or an exaggerated increase in pulmonary artery systolic pressure (PASP) in response to hypoxia? What is the main finding and its importance? PFO+ had a greater A-aDO2 while breathing air, 16% and 14% O2 , but not 12% or 10% O2 . PASP increased equally in hypoxia between PFO+ and PFO- . These data suggest that PFO+ may not have an exaggerated acute increase in PASP in response to hypoxia. ABSTRACT: Patent foramen ovale (PFO) is present in 30-40% of the population and is a potential source of right-to-left shunt. Accordingly, those with a PFO (PFO+ ) may have a larger alveolar-to-arterial difference in PO2 ( A-aDO2 ) than those without (PFO- ) in normoxia and with mild hypoxia. Likewise, PFO is associated with high-altitude pulmonary oedema, a condition known to have an exaggerated pulmonary pressure response to hypoxia. Thus, PFO+ may also have exaggerated pulmonary pressure increases in response to hypoxia. Therefore, the purposes of the present study were to systematically determine whether or not: (1) the A-aDO2 was greater in PFO+ than in PFO- in normoxia and mild to severe hypoxia and (2) the increase in pulmonary artery systolic pressure (PASP) in response to hypoxia was greater in PFO+ than in PFO- . We measured arterial blood gases and PASP via ultrasound in healthy PFO+ (n = 15) and PFO- (n = 15) humans breathing air and 30 min after breathing four levels of hypoxia (16%, 14%, 12%, 10% O2 , randomized and balanced order) at rest. The A-aDO2 was significantly greater in PFO+ compared to PFO- while breathing air (2.1 ± 0.7 vs. 0.4 ± 0.3 Torr), 16% O2 (1.8 ± 1.2 vs. 0.7 ± 0.8 Torr) and 14% O2 (2.3 ± 1.2 vs. 0.7 ± 0.6 Torr), but not 12% or 10% O2 . We found no effect of PFO on PASP at any level of hypoxia. We conclude that PFO influences pulmonary gas exchange efficiency with mild hypoxia, but not the acute increase in PASP in response to hypoxia.

Hypoxemia in COVID-19 patients: An hypothesis.

The current SARS-Cov-2 virus pandemic challenges critical care physicians and other caregivers to find effective treatment for desperately ill patients - especially those with sudden and extreme hypoxemia. Unlike patients with other forms of Acute Respiratory Distress Syndrome, these patients do not exhibit increased lung stiffness or dramatic dyspnea., even in the presence of arterial blood oxygen levels lower than that seen normally in mixed venous blood. Urgent intubation and mechanical ventilation with high inflation pressures and raised inhaled oxygen concentration have proved unhelpful or worse, but why? Our Hypothesis is that sudden opening of a previously undetected probe-patent foramen ovale (PPFO) may explain this mystery. As hypoxemia without acidosis is a rather weak stimulus of dyspnea or increased ventilation, and opening of such an intracardiac shunt would not worsen lung mechanical properties, the absence of dramatic symptom changes would not be surprising. We point out the high frequency of PFO both in life and at autopsy, and the physiological evidence of large shunt fractions found in Covid-19 patients. Published evidence of hypercoagulability and abundant evidence of pulmonary emboli found at autopsy are in accord with our hypothesis, as they would contribute to raised pressure in the pulmonary arteries and right heart chambers, potentially causing a shunt to open. We review the interaction between viral corona spike protein and ACE-2 receptors present on the surface of alveolar lining cells, and contribution to hypercoagulabilty caused by the spike protein. Search for an open PFO after a large drop in arterial oxygen saturation can be performed at the bedside with a variety of well-established techniques including bedside echocardiography, nitrogen washout test, and imaging studies. Potential treatments might include balloon or patch closure of the shunt, and various drug treatments to lower pulmonary vascular resistance.