Transesophageal echocardiography for quantifying size of patent foramen ovale in patients with cryptogenic cerebrovascular events

Long-term clinical outcomes for patients with uncrossable patent foramen ovale

Introduction

Patent foramen ovale (PFO) closure is performed in selected patients with cryptogenic stroke to prevent recurrence. The prognosis of patients with uncrossable PFO after failed guidewire or catheter passage during the procedure remains unknown. We compared the long-term prognosis between uncrossable PFO and successful PFO closure in patients with high-grade PFO shunts.

Methods

We analyzed patients who underwent PFO closure for stroke or transient ischemic attack (TIA) prevention at Gachon University Gil Medical Center between April 2010 and March 2022. The primary outcome was a composite of recurrent stroke or TIA. Secondary outcomes included stroke, TIA, all-cause death, and a composite of stroke, TIA, and all-cause death.

Results

Of 286 patients, 245 were included in the analysis after excluding those with transseptal puncture technique usage or concurrent atrial septal defect. Among them, 82 had uncrossable PFO, and 163 underwent successful PFO closure. Large shunts were more prevalent in the PFO closure group compared to the uncrossable PFO group (62.0% vs. 34.1%, P < 0.001), and resting shunts were also more common in the PFO closure group (17.8% vs. 2.4%, P < 0.001). Stroke or TIA occurred in 2 patients (2.4%) in the uncrossable PFO group and 8 patients (4.9%) in the PFO closure group (hazard ratio, 1.44; 95% confidence interval, 0.30-6.81; P = 0.647). Additionally, no disparities in the occurrence of stroke or TIA were found in subgroups divided by baseline characteristics, RoPE score, or shunt grade.

Conclusion

Clinical outcomes for patients with uncrossable PFO seem similar to those with successful PFO closure.

Microembolic signal detection by transcranial Doppler: Old method with a new indication

Transcranial Doppler (TCD) is useful for investigation of intracranial arterial blood flow and can be used to detect a real-time embolic signal. Unfortunately, artefacts can mimic the embolic signal, complicating interpretation and necessitating expert-level opinion to distinguish the two. Resolving this situation is critical to achieve improved accuracy and utility of TCD for patients with disrupted intracranial arterial blood flow, such as stroke victims. A common type of stroke encountered in the clinic is cryptogenic stroke (or stroke with undetermined etiology), and patent foramen ovale (PFO) has been associated with the condition. An early clinical trial of PFO closure effect on secondary stroke prevention failed to demonstrate any benefit for the therapy, and research into the PFO therapy generally diminished. However, the recent publication of large randomized control trials with demonstrated benefit of PFO closure for recurrent stroke prevention has rekindled the interest in PFO in patients with cryptogenic stroke. To confirm that emboli across the PFO can reach the brain, TCD should be applied to detect the air embolic signal after injection of agitated saline bubbles at the antecubital vein. In addition, the automated embolic signal detection method should further facilitate use of TCD for air embolic signal detection after the agitated saline bubbles injection in patients with cryptogenic stroke and PFO.

Contrast Transthoracic Echocardiography Using 50% Glucose as a Contrast Agent for Screening of a Patent Foramen Ovale

A patent foramen ovale (PFO) is considered a risk factor for neurologic events. The goal of the study described here was to assess the feasibility, advantages, diagnostic sensitivity and accuracy of contrast transthoracic echocardiography examination (cTTE) using 50% glucose as a contrast agent in comparison with the use of agitated saline as contrast to screen for PFO. In our study, we found that the peak time, effective duration and duration of microbubbles produced by 50% glucose were all longer than those produced by the physiologic saline. The sensitivities for detection of PFO with cTTE using physiologic saline and 50% glucose as contrast were 83% (20/24) and 100% (24/24), respectively. TEE suggested a PFO in 24 patients in two groups. Use of 50% glucose as a contrast agent in cTTE examination enables ultrasound technicians to easily observe the right-to-left shunt across the PFO. However, the sensitivities for detection of PFO with cTTE using 50% glucose did not statistically significantly differ from those for physiologic saline.

Patent foramen ovale and atrial fibrillation as causes of cryptogenic stroke: is treatment with surgery superior to device closure and anticoagulation? A review of the literature

Closure of persistent foramen ovale (PFO) to avoid cryptogenic strokes is performed globally with enthusiasm but lacks prove of efficacy. We present a 79-year-old man who had had a PFO device introduced nine years previously because of cryptogenic strokes presenting as syncopes. The patient was referred from his general practitioner with two new syncopes. Transthoracic echocardiography revealed no cardiac causes of embolism. Transesophageal echocardiography (TEE) revealed a misplaced device like an umbrella in a storm, but no septum defects. Holter revealed seconds-long episodes of atrial fibrillation (AF). The patient was successfully treated with anticoagulation.

A literature review showed that: (i) the efficacy of PFO closure devices has not been proven in any trial, but was demonstrated in a meta-analysis comparing three different devices; (ii) PFO devices are rarely controlled by TEE during or after insertion; (iii) residual shunts are detected in up to 45% of cases; (iv) there is an increased rate of post-arrhythmic complications; (v) the risk of AF in congenital heart disease increases with increasing age, with a 13% risk of transient ischemic attacks and stroke; and (vi) surgical treatment of PFO was found to have a 4.1% risk of complications including stroke.

The question to be asked is whether device closure of PFO should be avoided, considering that PFO is a congenital heart defect with risks of AF and (cryptogenic) stroke? Heart surgery should be a treatment option for symptomatic PFO.

Effects of Patent Foramen Ovale Closure on Obstructive Sleep Apnea Syndrome: PCOSA Study

BACKGROUND

Previous studies have shown a higher prevalence of patent foramen ovale (PFO) in patients with obstructive sleep apnea syndrome (OSAS). Right to left shunting through a PFO may be encouraged by the respiratory physiology of OSAS, contributing to the disease pathophysiology. We assessed whether PFO closure would improve respiratory polygraphy parameters compared with baseline measurements in patients with OSAS.

METHODS

Twenty-six patients with newly diagnosed OSAS and a moderate-large PFO (prevalence, 18% of 143 patients screened) were referred for PFO closure. The oxygen desaturation index (ODI), apnea-hypopnea index (AHI), Epworth Sleepiness Scale (ESS), 6-minute walk test (6MWT), and Sleep Apnea Quality of Life Index (SAQLI) results were compared in these patients at baseline (before continuous positive pressure ventilation [CPAP]) and at 6-month follow-up (after interrupting CPAP for 1 week).

RESULTS

All PFOs were safely sealed at 6 months, as confirmed by repeated transthoracic echocardiography. The ODI (44.8 [interquartile range (IQR), 31.2-63.5) vs 42.3 [IQR, 34.0-60.8]; P = 0.89) and AHI (47.9 [IQR, 31.5-65.2] vs 42.3 [IQR, 32.1-63]; P = 0.99) did not change after PFO closure nor did the 6MWT, although the ESS (13.0 [IQR, 12.0-16.8] vs 6.0 [IQR, 4.0-8.8]; P < 0.001) and the SAQLI (3.4 [IQR, 2.8-4.3] vs 4.4 [IQR, 3.9-5.3]; P < 0.001) did improve.

CONCLUSIONS

The prevalence of PFO in OSAS appears to be no higher than that in the general population. Although PFO closure is safe and effective, it did not improve respiratory polygraphy measures of OSAS severity. The improvement in the ESS and SAQLI likely reflect residual benefits from CPAP.

Recurrent and Residual Shunts After Patent Foramen Ovale Closure: Results From a Long-Term Transcranial Doppler Study

OBJECTIVES

Assess the evolution of right-to-left shunt (RLS) after transcatheter patent foramen ovale (PFO) closure.

BACKGROUND

Despite the high number of interventional procedures performed worldwide, limited systematic data on the long-term abolition of RLS after percutaneous closure are available.

METHODS

All patients treated at our Institution between February 2001 and July 2009 were included in this single center, prospective study, and were asked to repeat late contrast transcranial Doppler (cTCD). Rate of complete closure, residual RLS (i.e., a shunt that persists after closure), and recurrent RLS (i.e., a shunt that reappears after a previous negative cTCD) was assessed.

RESULTS

Long-term follow-up was completed in 120 patients (56% male). RLS was still detectable 4.9 ± 2.3 years (range 1.3-10.3) after the procedure in 55 patients; 20 (17%) had residual RLS and 35 (29%) had recurrent RLS. Multivariate analysis revealed that significant predictors of residual RLS included post-procedural shunt at transesophageal echocardiography (OR 3.07, 95%CI 0.97-9.7), use of a bigger device (35 vs 25 mm, OR 3.85, 95%CI 1.22-12.2) and length of follow-up (OR 0.75, 95%CI 0.57-0.98), while only length of follow-up (OR 0.77, 95%CI 0.62-0.95) was associated with recurrent RLS. Neurological recurrences (1 stroke, 6 transient ischemic attacks) were equally distributed between the groups.

CONCLUSION

A significant number of recurrent and residual shunts may be observed by cTCD up to 5 years after PFO closure. Management of late RLSs includes periodic re-evaluation, exclusion of device-induced complications or secondary sources of RLS, and optimization of antithrombotic treatment with or without a second intervention.

Correlation between Patent Foramen Ovale, Cerebral "Lesions" and Neuropsychometric Testing in Experienced Sports Divers: Does Diving Damage the Brain?

SCUBA diving exposes divers to decompression sickness (DCS). There has been considerable debate whether divers with a Patent Foramen Ovale of the heart have a higher risk of DCS because of the possible right-to-left shunt of venous decompression bubbles into the arterial circulation. Symptomatic neurological DCS has been shown to cause permanent damage to brain and spinal cord tissue; it has been suggested that divers with PFO may be at higher risk of developing subclinical brain lesions because of repeated asymptomatic embolization of decompression-induced nitrogen bubbles. These studies however suffer from several methodological flaws, including self-selection bias. We recruited 200 volunteer divers from a recreational diving population who had never suffered from DCS; we then randomly selected 50 of those for further investigation. The selected divers underwent brain Magnetic Resonance Imaging to detect asymptomatic brain lesions, contrast trans-oesophageal echocardiography for PFO, and extensive neuro-psychometric testing. Neuro-psychometry results were compared with a control group of normal subjects and a separate control group for subjects exposed to neurotoxic solvents. Forty two divers underwent all the tests and are included in this report. Grade 2 Patent Foramen Ovale was found in 16 (38%) of the divers; brain Unidentified Bright Objects (UBO's) were found in 5 (11.9%). There was no association between PFO and the presence of UBO's (P = 0.693) or their size (p = 0.5) in divers. Neuropsychometric testing in divers was significantly worse from controls in two tests, Digit Span Backwards (DSB; p < 0.05) and Symbol-Digit-Substitution (SDS; p < 0.01). Compared to subjects exposed to neurotoxic solvents, divers scored similar on DSB and SDS tests, but significantly better on the Simple Reaction Time (REA) and Hand-Eye Coordination (EYE) tests. There was no correlation between PFO, number of UBO's and any of the neuro-psychometric tests. We conclude that for uneventful recreational diving, PFO does not appear to influence the presence of UBO's. Diving by itself seems to cause some decrease of short-term memory and higher cognitive function, including visual-motor skills; this resembles some of the effects of nitrogen narcosis and we suggest that this may be a prolonged effect of diving.

The RoPE Score and Right-to-Left Shunt Severity by Transcranial Doppler in the CODICIA Study

BACKGROUND

For patients with cryptogenic stroke (CS) and patent foramen ovale (PFO), it is unknown whether the magnitude of right-to-left shunt (RLSh) measured by contrast transcranial Doppler (c-TCD) is correlated with the likelihood an identified PFO is related to CS as determined by the Risk of Paradoxical Embolism (RoPE) score. Additionally, for patients with CS, it is unknown whether PFO assessment by c-TCD is more sensitive for identifying RLSh compared with transesophageal echocardiography (TEE). Our aim was to determine the significance of RLSh grade by c-TCD in patients with PFO and CS.

METHODS

We evaluated patients with CS who had RLSh quantified by c-TCD in the Multicenter Study into RLSh in Cryptogenic Stroke (CODICIA) to determine whether there is an association between c-TCD shunt grade and the RoPE Score. For patients who underwent c-TCD and TEE, we determined whether there is agreement in identifying and grading RLSh between these two modalities.

RESULTS

The RoPE score predicted the presence versus the absence of RLSh documented by c-TCD (c-statistic = 0.66). For patients with documented RLSh by c-TCD, shunt severity was correlated with increasing RoPE score (rank correlation (r) = 0.15, p = 0.01). Among 293 patients who had both c-TCD and TEE performed, c-TCD was more sensitive (98.7%) for detecting RLSh. Of the 97 patients with no PFO identified on TEE, 28 (29%) had a large amount of RLSh seen on c-TCD.

CONCLUSIONS

For patients with CS, severity of RLSh by c-TCD is positively correlated with the RoPE score, indicating that this technique for shunt grading identifies patients more likely to have pathogenic rather than incidental PFOs. c-TCD is also more sensitive in detecting RLSh than TEE. These findings suggest an important role for c-TCD in the evaluation of PFO in the setting of CS.

Transesophageal echocardiography: a complementary view of the heart

Transesophageal echocardiography has been widely used as a diagnostic tool during the past two decades to detect cardiac abnormalities that are not visible or poorly visible with transthoracic echocardiography. At present, transesophageal echocardiography is a cornerstone of modern diagnosis of several cardiac diseases, providing diagnostic, prognostic and therapeutic information. In this review, the present status of transesophageal echocardiography not only as a diagnostic tool, underlining its effects on clinical decision making, but also as a monitoring adjunct for many interventional cardiac procedures is examined.

Diagnosis of ischemic stroke

Early stroke management, and early initiation of secondary stroke prevention, may improve outcomes in patients with acute ischemic stroke. However, <10% of patients with acute ischemic stroke arrive at the receiving hospital within 3 hours of symptom onset. Factors such as poor public awareness of symptoms, lack of rapid detection by emergency medical services (EMS), poor coordination between EMS and the hospital emergency department, or delay of diagnosis on arrival at the emergency department are all contributing factors in the failure to provide prompt diagnosis and treatment of acute ischemic stroke. This article focuses on the critical steps in diagnosing ischemic stroke, starting at the initial patient evaluation by emergency personnel. Stroke mimics and different imaging techniques that may be used in the differential diagnosis and evaluation of acute ischemic stroke are also discussed.

Lack of association between right-to-left shunt and cerebral ischemia after adjustment for gender and age

Introduction

A number of studies has addressed the possible association between patent foramen ovale (PFO) and stroke. However, the role of PFO in the pathogenesis of cerebral ischemia has remained controversial and most studies did not analyze patient subgroups stratified for gender, age and origin of stroke.

Methods

To address the role of PFO for the occurrence of cerebral ischemia, we investigated the prevalence of right-to-left shunt in a large group of patients with acute stroke or TIA. 763 consecutive patients admitted to our hospital with cerebral ischemia were analyzed. All patients were screened for the presence of PFO by contrast-enhanced transcranial Doppler sonography at rest and during Valsalva maneuver. Subgroup analyses were performed in patients stratified for gender, age and origin of stroke.

Results

A right-to-left shunt was detected in 140 (28%) male and in 114 (42%) female patients during Valsalva maneuver, and in 66 (13%) and 44 (16%) at rest respectively. Patients with right-to-left shunt were younger than those without (P < 0.001). PFO was associated with stroke of unknown origin in male (P = 0.001) but not female patients (P > 0.05). After adjusting for age no significant association between PFO and stroke of unknown origin was found in either group.

Conclusion

Our findings argue against paradoxical embolization as a major cause of cerebral ischemia in patients with right-to-left shunt. Our data demonstrate substantial gender-and age-related differences that should be taken into account in future studies.

Percutaneous closure of patent foramen ovale in patients with presumed paradoxical embolism: periprocedural results and midterm risk of recurrent neurologic events

OBJECTIVE

To report our data on selected patients with previous paradoxical embolism who underwent transcatheter patent foramen ovale (PFO) closure.

METHODS

Between July 2001 and July 2007, percutaneous PFO closure was performed on 128 patients (65 women, mean age: 46 +/- 12.8 years). Patent foramen ovale closure was recommended for secondary prevention in patients with previous transient ischemic attacks (52.5%), stroke (46%), or peripheral embolism (1.5%).

RESULTS

Implantation was successful in all patients, and at the end of intervention, complete PFO closure was achieved in 70.3% of them. There were no "major" complications (ie, deaths, device embolization or thrombosis, need for cardiac surgery). The overall incidence of complications (mostly hemorrhagic) was 7%. The mean follow-up period was 32 months. Complete closure had been achieved in 78.4% and in 82.5% of patients at the third month of transesophageal echocardiography examination and at the sixth month of transcranial Doppler examination, respectively. There were no recurrent thromboembolic events during the follow-up period.

CONCLUSIONS

Percutaneous closure of PFO is a feasible procedure, but it is not a risk-free technique. However, in correctly selected patients (ie, large PFO and those at risk for neurologic relapse), nearly complete PFO closure seems to provide protection from future neurologic ischaemic events at midterm follow-up.

Randomized study comparing mechanical with electronic 2-dimensional intracardiac ultrasound monitoring (MEDIUM) during percutaneous closure of patent foramen ovale in adult patients with cryptogenic stroke

BACKGROUND

Previous studies have shown that mechanical and electronic intracardiac echocardiography (ICE) improves ultrasound monitoring during transcatheter patent foramen ovale (PFO) interventional closure.

OBJECTIVES

This study sought to compare the procedural data, clinical imaging quality, and effectiveness PFO closure by using two different ICE monitoring modalities.

METHODS

Patients referred for PFO closure (n = 82) were randomly assigned to mechanical (group 1) or electronic (group 2) ICE monitoring of Amplatzer device implantation. The digital ICE images were evaluated offline by means of absolute visual grading analysis score (VGAS(abs)), and the residual shunting at follow-up were assessed by means of contrast echocardiographic studies, all blinded regarding the ICE closure monitoring modality.

RESULTS

The two groups were comparable with respect to clinical baseline characteristics, intracardiac fossa ovalis measurements, and procedural data (fluoroscopy time, procedure time and measurement of the amount of radiation that the patients absorbed). The total VGAS(abs) ranked the mechanical clinical images in a higher order than the electronic ones (3.78 +/- 0.09 vs 3.58 +/- 0.12, P = 0.005); additionally, three patients (7.3%) of group 2 needed to cross over to mechanical ICE monitoring because a right-convex atrial septal aneurysm configured itself incompletely. No differences in rates of residual shunting were observed at 12 months follow-up between the two groups (97.5% vs 94.7%, P = 0.951).

CONCLUSIONS

Electronic monitoring of PFO closure performed a less diagnostic impact than the mechanical one while maintaining comparable procedural data and clinical outcome. These results represent an important step in validating these new intracardiac ultrasound imaging modalities.

The Incidental Finding of a Patent Foramen Ovale During Cardiac Surgery: Should It Always Be Repaired? A Core Review

With the increased use of intraoperative transesophageal echocardiography, patent foramen ovale (PFO) has become a common finding during heart surgery. This finding presents a difficult dilemma for cardiac surgeons, since the impact of intraoperatively diagnosed PFOs on postoperative outcome is unknown. Changes in the surgical plan required for closure of a PFO subject the patient to the possibility of additional risk. On the other hand, a decision to not close a PFO exposes the patient to unclear immediate and long-term consequences. Deciding whether or not to close a PFO currently depends on the clinicians' personal preferences, the probability of intraoperative and postoperative hypoxemia, and any anticipated deviation from the initial surgical plan. Most clinicians agree that an intraoperatively diagnosed PFO must be closed when surgery leads to a high risk of hypoxemia (e.g., left ventricular assist devices placement, heart transplantation); should be closed in most cases when minimal deviation from the initial surgical plan is needed for PFO closure (e.g., mitral valve or tricuspid valve surgeries); and probably, should be closed during heart surgeries performed without atriotomy and bicaval cannulation when the risk of perioperative or remote PFO-related complications is increased. The recent development of percutaneous methods of PFO closure provides a valuable backup for those cases when PFO is not closed and postoperative hypoxemia or other complications may be attributable to the uncorrected PFO.

Interatrial septum rupture during balloon measurement of a patent foramen ovale in a young patient presenting cryptogenic stroke

We report the case of a 36-year-old woman admitted for cryptogenic stroke, in whom the Patent Foramen Ovale (PFO) diameter measurement, with a purpose built sizing balloon, performed before the closure procedure, was complicated with the rupture of the inter-atrial septum generating an Atrial Septal Defect (ASD) with a significant left-to-right shunt. This kind of complication may not be easy to handle, changing the initial procedural strategy from PFO to ASD closure technique requiring specific material and operator's technical skill.

Patent Foramen Ovale: Assessment, Clinical Significance and Therapeutic Options

Foramen ovale plays an important function in the fetus but is of no physiologic significance after birth and closes in most individuals. In about one fourth of the population, however, foramen ovale remains open for life and has been associated with cerebrovascular accidents, especially in younger patients, presumably through paradoxical embolism. Patent foramen ovale (PFO) has also been associated with hypoxia, migraine headaches and neurologic findings of decompression illness in scuba divers. Availability of transesophageal echocardiography and its frequent use in the management of patients with stroke has lead to frequent detection of PFO. In addition, the recent development of devices and techniques for percutaneous closure of PFO has resulted in widespread enthusiasm for such interventions, even when a clear etiologic role for PFO may not be established. In the United States, the Federal Drug Administration (FDA) has approved two such devices through compassionate investigational device exemption without adequate data from large randomized clinical studies. Other such devices are undergoing evaluation in clinical trials. Expert opinions have been helpful for clinical decision making in management of patients with PFO associated with stroke, hypoxia, decompression sickness and migraine headaches.

Ischemic stroke and patent foramen ovale: case report

Approximately 40% of ischemic strokes have no clearly definable etiology and are termed cryptogenic strokes. Patent foramen ovale, a small communication between the left and right atria, is considered to be a risk factor for cerebral embolism. In this study, we report the case of a 29-year-old woman with diagnosis of ischemic stroke due to patent foramen ovale who has undergone percutaneous endovascular closure. The aim of this report is to discuss the relevant aspects of the patent foramen ovale and the cryptogenic stroke, its clinical presentation, diagnosis, management and recurrence.

Patent foramen ovale

Patent foramen ovale is incriminated in patients with cryptogenic stroke; however, concrete evidence that closure of patent foramen ovale using various devices is superior to continued medical therapy is not yet available. Controlled randomized trials are well underway to address this issue.

A large Eustachian valve is a confounder of contrast but not of color Doppler transesophageal echocardiography in detecting a right-to-left shunt across a patent foramen ovale

BACKGROUND

Transesophageal contrast echocardiography (cTEE) is considered to be the method of choice for diagnosing patent foramen ovale (PFO), but its diagnostic accuracy compared with color Doppler guided TEE in the presence of an Eustachian valve (EV) has not been evaluated. The main aim of this study was to assess the diagnostic accuracy for PFO diagnosis of color Doppler TEE at low pulse repetition frequency.

METHODS

We ascertained the presence of PFO and EV using cTEE and transthoracic contrast echocardiography (cTTE) in 292 consecutive patients (age 42+/-12 years) with cryptogenic stroke. A diagnosis of PFO was based on the observation of right-to-left shunting of contrast bubbles or by color Doppler with pulse repetition frequency of 20-30 cm/s. An EV with a diameter of >1.5 cm in the bicaval view was considered large.

RESULTS

Overall 204 patients (70%) had evidence of a right-to-left shunt by either contrast echo method. Shunting was demonstrated more frequently by color Doppler than by cTEE, either spontaneously (133 vs. 92; p=0.01) or during provocative maneuvers (166 vs. 184; p=0.01). The sensitivity of color Doppler was significantly higher than that of cTEE (90% vs. 81%; p=0.01). A large EV was found in 37 patients, 31 (84%) of whom had a PFO. The presence of a large EV did not significantly influence the sensitivity of color Doppler for detecting shunting through a PFO, but the sensitivity of cTTE and cTEE was significantly reduced (from 88% to 42%, p<0.001).

CONCLUSIONS

Color Doppler TEE is more accurate than traditional cTEE for PFO diagnosis and is not negatively influenced by the presence of an EV, provided that a low pulse repetition frequency is used.

Prevalence and clinical significance of a patent foramen ovale in patients with chronic obstructive pulmonary disease

BACKGROUND

A patent foramen ovale (PFO) is not widely recognized as a factor contributing to hypoxemia in patients with chronic obstructive pulmonary disease (COPD). We therefore sought to clarify the prevalence and clinical significance of a PFO in patients with COPD, and to analyze the factors related to its occurrence.

METHODS

This study included 52 consecutive stable patients with COPD and 50 healthy controls. The demographic and clinical features of the study group were noted. To test for a PFO, standard and contrast transthoracic echocardiographic examinations were performed while resting and during the Valsalva maneuver (VM). Patients performed 6-min walking tests (6 MWT), and the distances traveled were measured.

RESULTS

During VM, we detected a PFO in 23 COPD patients and 10 healthy controls (P<0.01). A PFO was detected while resting in 11 COPD patients, but in none of the controls (P=0.001). Comparison of multiple parameters between COPD patients with and without a PFO during VM did not reveal any clinically significant differences. When we compared COPD patients with and without a PFO during resting, however, we found that the former had longer durations of disease, lower PaO2 and SaO2, higher dyspnea scores, shorter distances walked during 6 MWT and higher desaturation rates (P<0.05). Logistic regression analysis showed that longer duration of disease, lower SaO2 and higher systolic pulmonary artery pressure were independent predictors of the occurrence of a PFO in resting COPD patients.

CONCLUSIONS

The prevalence of a PFO is higher in patients with COPD than in healthy individuals. The presence of a PFO while resting may contribute significantly to the deterioration of arterial oxygenation and performance status. These findings indicate that a PFO may be a principle cause of hypoxemia in patients with COPD.

A critical review of patent foramen ovale detection using saline contrast echocardiography: when bubbles lie

Saline and indocyanine green dye were the first agents noted to produce a contrast effect when injected peripherally during M-mode echocardiographic imaging, although it was subsequently found that almost any type of injected solution would have this effect. These first-generation contrast agents were limited to opacification of right heart structures, and they prompted subsequent development of agents that traverse pulmonary circulation. Although opacification limited to right heart structures is considered a limitation of these first-generation agents, this is an advantage when attempting to identify the presence of right-to-left shunt. First-generation air contrast is considered the gold standard for identification of patent foramen ovale (PFO). However, PFO investigators have used varying criteria to define abnormal contrast studies. There are also multiple mechanisms by which saline contrast studies may produce both false-positive and false-negative results for presence of PFO. There is mounting experimental evidence that PFO is associated with cerebral ischemia and migraine headache, with a resulting evolution of devices for percutaneous closure of these shunts. Echocardiographic physicians must be aware of potential pitfalls of the air contrast technique to avoid exposing patients to unnecessary risk of closure devices, and missing the potential benefit of shunt closure in appropriately selected patients.

Secondary prevention after cryptogenic cerebrovascular events in patients with patent foramen ovale

BACKGROUND

Patients with patent foramen ovale and cryptogenic stroke are at risk of recurrence, but there are few data on strategies to prevent this.

METHODS

We studied 280 consecutive patients with cryptogenic cerebrovascular events and a patent foramen ovale examined by multiplane transesophageal echocardiography. Patients received platelet inhibitors (n = 66) or anticoagulation (n = 47) or underwent device closure (n = 167). During the mean follow-up of 2.6 years, we compared the frequency of recurrent events, death and severe treatment complications.

RESULTS

A total of 33 (12%) patients had a recurrent cerebrovascular event. The annual recurrence rates were 13% in patients treated with platelet inhibitors, 5.6% in those on oral anticoagulation, and 0.6% in those after device closure. Independent predictors of recurrent cerebrovascular events were a patent foramen ovale larger than 4 mm (hazard ratio 3.8, 95% CI 1.2-11.2; p = 0.017) or previous strokes (hazard ratio 4.3, 95% CI 2.0-9.2; p < 0.001). Interventional closure of the patent foramen ovale decreased the risk of a recurrent event compared with oral anticoagulation (hazard ratio 0.06, 95% CI 0.12-0.29; p < 0.001), whereas antiplatelet therapy showed a trend to an increased risk (hazard ratio 2.3; 95% CI 0.9-5.5; p = 0.055). Major side effects occurred in 7 anticoagulated patients and in 13 patients after device closure. There were two non-vascular deaths and one fatal hemorrhagic stroke.

CONCLUSIONS

Patients with a large patent foramen ovale and a cryptogenic cerebrovascular event had a substantial risk of recurrence even with medical treatment. Risk of recurrence was lower after device closure of the patent foramen ovale.

The echocardiographer and the diagnosis of patent foramen ovale

PFO is diagnosed by echocardiography using the combination of transthoracic two-dimensional imaging of the interatrial septum, followed by color and spectral Doppler (and if necessary saline contrast) imaging. Transesophageal imaging is an important adjunct when transthoracic imaging is not conclusive or yields suboptimal images.Three-dimensional echocardiography is useful for defining fenestrations within a PFO.

Definitions and pathophysiology of the patent foramen ovale: broad overview

This article presents definitions and discusses pathophysiology pertaining to the patent foramen ovale.

Percutaneous closure of patent foramen ovale guided by intracardiac echocardiography and performed through the transfemoral approach in the presence of previously placed inferior vena cava filters: a case series

We present three patients with cryptogenic stroke who underwent transcatheter closure of a patent foramen ovale. All patients have had history of deep venous thrombosis and pulmonary embolism with placement of inferior vena caval filters. The patients were not initially considered suitable candidates for the procedure because of risk of dislodgment of previously implanted inferior vena cava filter.

Diagnosis of Patent Foramen Ovale Using Contrast-Enhanced Dynamic MRI: A Pilot Study

OBJECTIVE

The aim of this study was to evaluate the feasibility of dynamic contrast-enhanced MRI for detection of patent foramen ovale.

SUBJECTS AND METHODS

Fifteen patients with and five patients without patent foramen ovale underwent transesophageal echocardiography and MRI, which were performed during the Valsalva maneuver. Grading results (grade 0, no patent foramen ovale and grades 1-3, minor to major enhancement due to intracardiac shunt) were assessed visually. Signal-intensity curves in the left atrium and in a pulmonary vein served to underline the diagnosis.

RESULTS

The diagnoses of all patients with (15/15) and without patent foramen ovale (5/5) were correct compared with the findings of the reference transesophageal echocardiography. In 12 (60%) of 20 patients, the grading scores were identical, and in four (20%) of 20 patients, the scores differed by more than one grade. Overall, there was a good correlation of grading scores (r = 0.7, p < 0.05). Using signal-intensity curves, we found that the patients with patent foramen ovale showed an additional signal peak in the left atrium before the enhancement of the pulmonary vein because of an intracardiac shunt. In three of 15 patients with patent foramen ovale, an atrial septal aneurysm was correctly diagnosed.

CONCLUSION

This pilot study shows that MRI is a new noninvasive method to detect patent foramen ovale and atrial septal aneurysm. A grading is possible but warrants further investigation regarding its predictive value and impact on treatment strategies.

Impending Paradoxical Cerebral Embolism in a Patient With Atrial Septal Aneurysm

There is increasing emphasis on the role of interatrial septal abnormalities, including patent foramen ovale and atrial septal aneurysm, in the genesis of stroke. However, a transseptal thrombus located in both atria is rarely visualized by echocardiography or other cardiac imaging techniques. It is also difficult to prove the mechanism of stroke in most clinical settings. In the present case of impending paradoxical cerebral embolism, the thrombus penetrating the atrial septal wall was visualized by transesophageal echocardiography.

Transesophageal Echocardiography as a Guide for Patient Positioning Before Neurosurgical Procedures in Semi-sitting Position

With an incidence of a patent foramen ovale in nearly one fourth of the normal population, neurosurgical procedures in the semi-sitting position are associated with the risk of paradoxical air embolism. The present study was undertaken to evaluate an anesthetic concept to detect a patent foramen ovale with the help of transesophageal echocardiography in anesthetized patients before neurosurgical procedures in the semi-sitting position. Transesophageal echocardiography was performed after induction of anesthesia before surgery to avoid additional physical and psychologic stress for the patients. Thirty-five neurosurgical patients scheduled for elective surgery in the semi-sitting position were examined with help of contrast transesophageal echocardiography. The data of the examined patients were analyzed with respect to efficiency, logistic efforts, and adverse events. Contrast transesophageal echocardiography was combined with a ventilation maneuver to increase right atrial pressure. A patent foramen ovale was detected in 3 of 35 patients. These patients were operated on in a supine position. Oral insertion of the echoprobe was possible in all patients without difficulties. A short-lasting hypertension was observed in 5 patients despite adequate analgesia and sedation. The average time of examination was 25 minutes. None of the patients showed paradoxical air embolism as judged by postoperative neurologic assessment. Contrast transesophageal echocardiography combined with a ventilation maneuver is an effective method in detecting a patent foramen ovale. Moreover, transesophageal echocardiography is a clinical guide to patient positioning. The method of anesthetic management presented to examine anesthetized patients immediately before surgery means less physical and psychologic stress for the patients and causes approximately a 30-minute delay of surgery.

Comparison of intracardiac echocardiography versus transesophageal echocardiography guidance for percutaneous transcatheter closure of atrial septal defect

Transcatheter closure of interatrial septal defects is guided by transesophageal echocardiography (TEE), which requires general anesthesia in most cases. Using a new intracardiac echocardiographic (ICE) catheter may avoid endotracheal and esophageal intubation while using only local anesthesia. Forty-two patients underwent transcatheter interatrial septal defect closure; half of them underwent TEE guidance with general anesthesia and the other half underwent ICE guidance with local anesthesia. Device deployment success rate, adequate 2-dimensional and Doppler visualization of the defect and deployment steps, interatrial communication closure at 24 hours, and at 3 and 6 months, procedure time length, complications, fluoroscopic time, and length of hospitalization were compared between both methods. All interventions were completed successfully with no complications, except for 1 patient in the TEE group who had a minor oral trauma. Echocardiographic visualization of the septal defect and deployment was adequate by both methods. Catheterization laboratory time (92 +/- 18 vs 50 +/- 12 minutes, p <0.001) and interventional procedure length (47 +/- 8 vs 35 +/- 6 minutes, p <0.001) were shortened using ICE. There was no difference in the rate of closure after 6-month follow-up by either method. ICE guidance offers equivalent echocardiographic views compared with TEE and similar rates of closure. ICE is associated with decreased procedure length while eliminating the risks of endotracheal or esophageal intubation and general anesthesia.