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A case of prenatal echocardiographic diagnosis of obstruction of the foramen ovale is described. Presentation was the ultrasound detection of unexplained marked right atrial and right ventricular dilation without fetal hydrops. It is speculated that fetal outcome depends on the severity and time of onset of foramen ovale obstruction in utero.
Hypoxemia can be an early life-threatening complication of orthotopic heart transplantation. Commonly, hypoxemia after orthotopic heart transplantation is due to pulmonary hypertension or pulmonary complications. Rarely, structural defects either in the donor or recipient heart can lead to life-threatening hypoxemia. This case illustrates hypoxemia after orthotopic heart transplantation caused by the development of a right-to-left shunt through a patent foramen ovale in the recipient which had preoperatively been hemodynamically insignificant. The refractory hypoxemia required emergency surgical correction of the patent foramen ovale within the first postoperative week. In addition, this case illustrates the unique application of different methods of echocardiograms providing noninvasive diagnosis of structural defects in orthotopic heart transplantation.
The role of patent foramen ovale (PFO) in cryptogenic stroke is still debated, but from recent follow-up studies it seems that the amount of right-to-left shunt (RLS) and the association with atrial septal aneurysm (ASA) are major determinants of stroke recurrence. PFO and RLS through the atrial chambers have been recently studied in a number of conditions not or marginally related to cerebrovascular disease. Historically the first studies addressed the presence of RLS in scuba divers as a possible abnormality related to decompression sickness (DS) of unknown aetiology. Despite initial debate there is now robust evidence to claim that patency of foramen ovale increases the risk of developing DS by two and half to four times. Patients with PFO-related DS tend to have early occurrence of symptoms after surfacing and a clinical presentation that indicates brain or upper cervical spinal cord involvement. Recent reports suggest that divers with hemodynamically significant RLS may have an increased risk of developing clinically asymptomatic multiple brain lesions. PFO has been found in patients suffering from migraine with aura with approximately the same frequency as that encountered in cryptogenic stroke patients. This finding has prompted speculations on the possible role of RLS in increasing the stroke risk in migraineurs and in the pathophysiology of the aura. Recent reports showing that migraine with aura is dramatically improved after transcatheter closure of PFO suggest that migraine with aura may indeed be triggered by humoral factors that reach the brain by escaping the pulmonary filter. A RLS is involved in a rare condition known as platypnea-orthodeoxia and perhaps underlies an increased risk of cerebral complications after major orthopedic surgery. Valsalva-like activities often precede the occurrence of attacks of transient global amnesia (TGA) and abnormalities consistent with hypoperfusion of deep limbic structures have been reported during a typical TGA episode. This had raised the hypothesis that TGA may be triggered by paradoxical embolism of platelets aggregates in the posterior circulation, but the search for an increased frequency of PFO in TGA patients has yielded conflicting results. Conditions that determine an increase in pulmonary pressure may facilitate the opening of the virtual interatrial valve and thus promoting shunting of blood to the left heart chambers which in turn might contribute to further desaturation of arterial blood. It is therefore not surprising that RLS has been found in 70% of patients with chronic obstructive pulmonary disease and increased pulmonary pressure and in the same proportion of patients with obstructive sleep apnoea, a condition that ultimately may result in pulmonary hypertension. In conclusion, from the evidence gathered so far the picture is emerging of an important role of PFO in a number of non-stroke conditions, either as causative factor or as associated condition predisposing to complications. The availability of simple diagnostic techniques such as transcranial Doppler (TCD) to assess RLS will undoubtedly contribute a great deal of knowledge on the relevance in medicine of this hitherto neglected condition.
We describe two patients who underwent coronary artery bypass grafting complicated by postoperative hypoxemia due to a patent foramen ovale with right-to-left shunting. We discuss different hypotheses to explain the shunt: decreased right ventricular compliance, right atrial geometric changes due to septal distension or ischemia, exceeding filling pressure and localised haemorragic pericardial tamponade and low atrial pressure when correcting aortic stenosis. We emphasize the close interplay of pericardectomy and the four cardiac chambers including the distortion of the heart axis. The contrast echo produced by microbubbles of air is the safest and the most accurate procedure to detect the shunt. The two patients progressed positively with an extracorporeal circulation of short duration and without complications linked to the intervention. We conclude that postoperative unexplained hypoxemia must always exclude diagnosis of right-to-left shunting due to a patent foramen ovale (PFO).
OBJECTIVE: To define therapeutic strategy for management of patients with ischemic stroke due to a high probability of paradoxical embolism through a Patent Foramen Ovale (PFO). METHODS: Since 1988 all consecutive patients with cerebrovascular events and PFO from the Stroke Registry of our population-based primary-care center are prospectively studied and followed. Since 1992, among 118 patients with cryptogenic embolic brain infarct or transient ischemic attack (TIA) and PFO, 32 consecutive patients younger than 60 years who presented at least two of the following criteria were admitted for surgery: history of Valsalva strain before stroke (11); multiple clinical events (13); multiple infarcts on brain Magnetic Resonance Imaging (MRI) (15); atrial septal aneurysm (ASA) (16); large right-to-left shunt (> 50 microbubbles) (12). RESULTS: Operative time 135' +/- 33'. CPB time 34' +/- 14'. Aortic crossclamping time 16' +/- 6'. Post-operative bleeding 485 +/- 170 ml. No homologous blood transfusion required. No neurological, cardiac or renal complications. All patients were followed-up corresponding to a cumulative time of 601 patient-months. This revealed no recurrent vascular events nor silent new brain lesions on brain MRI. Systematic simultaneous contrast Trans Esophageal Echocardiography (TEE)-Trans Cranial Doppler showed a small residual interatrial shunt in two patients. CONCLUSION: Surgical closure of a patent foramen ovale can be accomplished with very low morbidity and reduce efficiently the risk of stroke recurrence. It seems to be the option of choice in selected patients with a higher (> 1.5%/year) risk of stroke recurrence.
A patent foramen ovale with right-to-left shunting was responsible, in part, for profound hypoxemia in a patient who required mechanical support with a left ventricular assist device for cardiogenic shock. The patent foramen ovale was detected with contrast transesophageal echocardiography, and the defect was closed successfully with a transcatheter septal defect closure device.
BACKGROUND: It is unclear whether medical or invasive (surgical or catheter interventional) treatment is preferable to prevent recurrence of cerebral ischemia in patients with patent foramen ovale (PFO) as the suspected cause of stroke and what the role of concomitant risk factors is in stroke recurrence. METHODS: Over a period of ten years, 124 patients (mean age 51 +/- 15 years) with cryptogenic cerebral ischemia and PFO were included into the study and prospectively followed over a mean of 52 +/- 32 months. Of these, 83 were treated medically, 34 underwent transcatheter closure, and seven had surgical closure of the foramen. Of the medically treated patients, 11 stopped medication during follow-up. Recurrent ischemic events and risk factors for recurrence were analyzed. RESULTS: Annual stroke recurrence rates were generally low and comparable in catheter and medically treated patients, and in patients who had stopped medication (2.9%/2.1%2.2%/year). Patients suffering from recurrence after transcatheter closure (n = 2) both had residual shunts. No stroke recurrence was observed in the few surgically treated patients. An atrial septal aneurysm was not a predictor of recurrent or multiple strokes (p > 0.05, OR = 0.31, and OR = 0.74). Large shunts and a history of previous ischemic events were considerably more frequent in patients with recurrent strokes (p < 0.05, OR = 5.0, and OR = 4.4). Pulmonary embolism and case fatality rates were significantly higher in patients with stroke recurrence (p < 0.001, and p < 0.01). CONCLUSIONS: The absolute risk of recurrent cerebrovascular events in patients with PFO receiving medical or catheter interventional therapy is low. The small group of untreated patients had a comparably low rate of stroke recurrences. Previous ischemic events and shunt size were risk factors in this observational study. Given conflicting findings across multiple studies, enrollment into a randomized controlled trial would be the optimal choice.
We present a male infant, born at term, who collapsed and died at 30 minutes of age. Autopsy demonstrated concordant atrioventricular and discordant ventriculo-arterial connections with premature closure of the oval foramen, which bulged markedly into the left atrium. Premature closure of the oval foramen is rare in the setting of transposition. As far as we know, there have been only three previously reported cases.
Patent foramen ovale (PFO) has been linked to ischemic strokes of undetermined cause (cryptogenic strokes). PFO-a remnant of fetal circulation when the foramen ovale does not seal after birth-can permit microemboli to escape the pulmonary filter into the intracranial circulation, causing stroke. Coexistent atrial septal aneurysm, pelvic deep vein thrombosis and inherited clotting factor deficiencies could potentiate stroke risk in patients with PFO. Transcatheter PFO closure, a minimally invasive procedure, is one technique used to prevent recurrent cerebrovascular events. A connection between PFO and migraine headache has been conceptualized from retrospective evidence of reduced migraine frequency and severity after PFO closure; however, prospective randomized trials are needed to verify the efficacy of PFO closure on migraine prevention. In this review we discuss embryologic origins, diagnostic techniques and treatment options for prevention of paradoxical embolism thought to be related to PFO, and the relation of PFO to cryptogenic stroke and migraine.
AIM: To assess the accuracy of panoramic radiography and spiral or computed tomography for the localisation of the mental foramen. MATERIALS AND METHODS: The distance from the alveolar crest to the mental foramen was measured from panoramic radiographs, spiral tomograms and CT scans. The same distance was measured during implant surgery using a specially designed caliper. RESULTS: Panoramic radiography showed more deviation (+0.6 mm) from the perioperative measurements than either spiral or computed tomography (+0.4 and -0.3 mm respectively). The difference was significant (P<0.05). In general, distances were overestimated on the panoramic radiographs. CONCLUSIONS: Cross-sectional imaging techniques are recommended for the pre-operative planning of implants in the posterior mandible.
Patients who have suffered a transient ischaemic attack or minor stroke are examined thoroughly to determine the aetiology of the cerebrovascular incident. An examination of the carotid arteries is compulsory to detect significant stenosis. In some patients, cardiogenic sources of emboli may be suspected. This study examined the possibilities of screening for patent foramen ovale (PFO) using i.v. injection of a microbubble solution with Doppler monitoring of the internal carotid artery (ICA) and the middle cerebral artery (MCA). Transoesophageal echocardiography (TEE) served as the gold standard. Twenty-three patients with a recent episode of cerebral ischaemia were examined: 12 patients with and 11 without PFO documented by TEE. After i.v. injection, microbubbles were monitored visually in the right and left atria and using Doppler sonography in the right ICA and in the right MCA. In the group with a PFO (n = 12), microbubbles were detected in the ICA in seven patients (7 of 12) and in the MCA in 10 patients (10 of 10). In the group without a PFO, microbubbles were detected in the ICA in one patient and in the MCA in two. This corresponds to a sensitivity and specificity, respectively, of 58% and 91% for the ICA/duplex technique and 100% and 82% for the MCA/transcranial Doppler technique. From this limited sample, it is shown that transcranial Doppler monitoring of the middle cerebral artery, but not ultrasound duplex monitoring of the internal carotid artery, can be used as screening for patent foramen ovale.
The patent foramen ovale (PFO) has been increasingly implicated in the aetiology of stroke, particularly in young patients with no other identifiable cause (cryptogenic stroke). The mechanism is by the passage of venous clots through the patent foramen into the arterial circulation, enabling cerebral embolism. Such patients with cryptogenic stroke and PFO are often treated with life-long anticoagulants or antiplatelet agents in an attempt to decrease the risk of a recurrence. Less commonly, surgical closure of the PFO has been undertaken in these patients. However, the recent evolution of closure devices that are delivered percutaneously by standard cardiac catheter techniques now offer an alternative non-surgical option. These alternative therapies are yet to be compared adequately. Two issues remain to be resolved. First, in determining appropriate therapy, patients with cryptogenic stroke may be divided into three groups: those with no PFO but an alternative unrecognized aetiology, those with an 'innocent' PFO and an alternative unrecognized aetiology and those with a causative PFO. The distinction between these groups clearly has important treatment implications. Second, the risk versus benefit of each available treatment modality must be determined for these different patient subgroups. These two issues require resolution before rational evidence-based treatment can be prescribed for patients with PFO and cryptogenic stroke.
The relationship between foramen ovale flow velocity waveforms and high-amplitude fetal breathing movements was studied in ten normal term pregnancies using Doppler ultrasonography. Peak systolic and averaged flow velocities demonstrated a statistically significant increase during fetal breathing activity, suggesting a raised pressure gradient between the right and left atria. This could be explained by a temporal reduction in pulmonary venous return to the left atrium during the inspiratory phase of the fetal breathing cycle. The breathing-related increase in foramen ovale flow velocity suggests that fetal breathing activity facilitates the distribution of well-oxygenated blood to the aorta and cerebral circulation.
PURPOSE: To assess distribution of temporal lobe spikes across different states of sleep and wakefulness in simultaneous scalp and foramen ovale (Fo) recordings. METHODS: The study included 12 patients with mesial temporal lobe epilepsy (MTLE). As part of their presurgical evaluation, patients underwent long-term video-EEG monitoring with combined scalp and foramen ovale electrodes (FoEs). In addition to traditional sleep scoring, waking was subdivided into eyes-opened and eyes-closed states, and rapid-eye-movement (REM) sleep was divided into phasic and tonic states. Spike counts were carried out visually for scalp and FoEs, and spiking rates were determined for each state. A ratio between FoE and scalp spiking rates also was calculated for each state. RESULTS: Scalp spiking showed a significant increase during NREM3,4, whereas FoE spiking increased during NREM2. The scalp/FoE ratio significantly increased during NREM3,4. A significant difference in spiking rate also was found between phasic and tonic REM states as well as between waking with eyes opened and closed in FoE recordings. CONCLUSIONS: Our data provide evidence of a discrepancy in spike distribution across different states of sleep and waking monitored by scalp and FoE recordings. We suggest that these discrepancies may reflect differences in archicortical and neocortical spike synchronization.
Dyspnea and hypoxemia are common postoperative problems following pneumonectomy. Platypnea, the increased dyspnea in the erect position relieved by assuming a prone position, has been reported as a result of right to left inter-atrial shunt. We report here on our experience with a patient who had severe platypnea with remarkable positional arterial desaturation following right pneumonectomy. After establishing the diagnosis with contrast-enhanced transesophageal echocardiography of the preoperatively undetected interatrial right-left shunt, cardiac surgery led to clinical improvement and resumption of platypnea. Given the rarity of the diagnosis, we think interatrial shunt, based on an open foramen ovale, should be taken into consideration when platypnea occurs in patients as a postoperative complication following lung surgery. Transesophageal echocardiography may be helpful in detecting patients with "anatomical closed but functional open" foramen ovale or genuine inter-atrial septal defect prior to lung surgery.
The foramen ovale which is the fetal connection between the right and left atrium persists in about 30 % of the adult population. In the presence of a persistent foramen ovale (PFO) shunting of blood may occur from the right to the left atrium, and bubbles can reach the systemic circulation during or after the decompression phase of a dive with compressed air. Therefore, divers with PFO may have an increased risk to develop ischemic cerebral lesions and neurologic decompression sickness (DCS). Significant right-to-left shunting may be diagnosed using transcranial doppler ultrasound of the medial cerebral artery and echocardiography with echo contrast media and Valsalva provocation. However, there are no official guidelines concerning PFO screening in medical fitness exams for professional or recreational divers in Germany. Therefore, it remains in the diver's choice to be screened for PFO. Divers with a history of DCS should be monitored for PFO, especially when diving strictly adhered to decompression tables. Divers with PFO who refuse to stop diving after DCS should be advised to adhere to very save dive profiles.
PURPOSE: Evaluation of the incidence of a midline sternal foramen, as a developmental anomaly, in order to avoid fatal complications following sternal puncture of sternal acupuncture treatment. MATERIAL AND METHODS: 100 chest computed tomograms were evaluated in reference to the incidence of this anomaly and its various features. RESULTS: The variety of CT aspects ranged from very incomplete types with only sandglass-like retraction of sternal cortex, to a complete foraminal defect. The incidence of midline sternal foramen in a feature bearing a risk of complication, is approximately 6%. CONCLUSION: We conclude that--if sternal acupuncture is planned in the region of corpus--previous radiographs should be done to rule out this anomaly. Furthermore, we strongly recommend the acupuncture technique of the "Wiener Schule", which prescribes a safe superficial-oblique approach to the sternum.
Premature closure of the foramen ovale is a rare cardiac anomaly. Severe right-sided heart failure accounts for the hepatomegaly, ascites, pleural and pericardial effusions, and generalized edema of these hydropic fetuses. Premature closure of the foramen ovale should be a part of the differential diagnosis when unexplained fetal hydrops is encountered.