Incidence Of Patent Foramen Ovale Research Articles

Presence of patent foramen ovale increases risk of filamentous thrombi on interatrial septum in atrial fibrillation/flutter patients

Abstract Introduction The presence of interatrial septum (IAS) strands in atrial fibrillation or flutter (Afi/Afl) patients is frequently overlooked despite being a common occurrence. Purpose The study aims to understand the prevalence and possible pathological nature of these strands. Methods The study included 454 consecutive Afi/Afl patients who underwent transesophageal echocardiography from June 2019 to January 2020. Patients were divided into two groups based on the presence of strands on the IAS (strand and non-strand group). The echocardiograms and clinical characteristics of the patients were reviewed. The difference between the two groups was compared using independent t or chi-square test. Univariate and multivariate logistic regression analyses were performed to identify factors associated with the IAS strands. The study also examined surgical samples of the IAS strands of a patient pathologically. Results The study found that 127 (28%) of the enrolled patients had strands on the right atrial side of the IAS. The strand group had a significantly higher incidence of patent foramen ovale (PFO) (p<0.0001) than the non-strand group. Patients in the strand group were also more likely to be over 60 years of age(p=0.085), obese(p=0.073), and have abnormal renal function(p=0.086). Multivariate analysis revealed that PFO was independently associated with the presence of IAS strands (OR=64.51, 95% CI: 31.35-132.76, p<0.0001). The pathological examination of the IAS strands in a patient revealed filamentous thrombi. Conclusions The study highlights the high prevalence of IAS strands in Afi/Afl patients. The presence of PFO significantly increases the risk of IAS filamentous thrombi. This study is the first report on the pathological nature of IAS filaments in Afi/Afl patients, offering important insights into the causes of Afi/Afl-induced cardiogenic embolism other than left atrial appendage thrombi.

Analysis of the value of echocardiographic parameters in the early diagnosis of preterm infants with bronchopulmonary dysplasia.

The objective of this study was to investigate the role of echocardiographic parameters in diagnosing bronchopulmonary dysplasia (BPD) in preterm infants. Ninety preterm infants with a gestational age of less than 32 weeks and a weight less than 1.5 kg, admitted to the neonatal intensive care unit of the hospital between January 2020 and January 2021, were selected for the study. The study subjects were divided into two groups: a BPD group (54 cases, observation group) and a non-BPD group (36 cases, control group). The correlation between tricuspid regurgitation (TR) velocity and BPD was investigated by detecting the cardiac function of preterm infants in both groups using a color Doppler ultrasound diagnostic instrument and analyzing the cardiac ultrasound results. The early prediction efficiency of TR velocity (m/s) for BPD was evaluated using the receiver operator characteristic (ROC) curve. The incidence of patent ductus arteriosus (PDA) and pulmonary hypertension (PH) in the observation group was significantly higher than that in the control group. The levels of left ventricular ejection fraction (LVEF) and left ventricular shorting fraction (LVFS) were significantly lower than those in the control group (p < 0.05). The incidence of patent foramen ovale (PFO), atrial septal defect (ASD), and ventricular septal defect (VSD) in the observation group were not significantly different from the control group (p > 0.05). The proportion of tricuspid regurgitation in the observation group was significantly higher than that in the control group, and the TR velocity was significantly higher than that in the control group. The Spearman correlation analysis showed that TR velocity (m/s) was positively correlated to BPD severity (r = 0.379, p < 0.05). The area under the curve (AUC) for predicting BPD with TR velocity was 0.735. The sensitivity and specificity were 88.0% and 62.6%, respectively, when the TR velocity was 1.45 m/s. Echocardiography is useful for understanding the degree of impaired cardiac function in preterm infants and for early detection of PH, which may reduce the mortality rate to a certain extent. The risk of BPD is significantly increased when TR velocity is higher than 1.45 m/s.

Patent foramen ovale in carcinoid heart disease: The potential role for and risks of percutaneous closure prior to cardiothoracic surgery.

Neuroendocrine tumours (NETs) are rare but once metastasised, can lead to the release of vasoactive substances into the systemic circulation, and the classical features of carcinoid syndrome (CS) such as flushing and diarrhoea. A consequence of CS is carcinoid heart disease (CHD) which primarily affects the right-sided heart valves and can eventually lead to right heart failure. In this cohort, tricuspid and/or pulmonary valve replacement provides symptomatic relief. A patent foramen ovale (PFO) in patients with CHD can lead to the shunting of oxygen deficient blood to the systemic circulation causing hypoxaemia and reduced exercise tolerance. Additionally, the haemodynamic changes caused by regurgitant right-sided heart valves can increase the patency of a PFO allowing the passage of vasoactive substances to the systemic circulation thereby affecting the left-sided heart valves. We present data on the incidence of PFO in patients referred for surgery at our centre, in which the standard approach is to close the defect at time of cardiothoracic surgery. In addition, we present a series of four cases that highlight how the option of percutaneous PFO closure prior to open valve surgery may reduce haemodynamic instability and open a window of opportunity to enhance preoperative status. Percutaneous PFO closure then acts as a bridge to definitive cardiothoracic surgery, although there are risks in such an approach.

Re-conceptualization of the “Chinese Expert Guidelines for the Prevention of Stroke Associated with Patent Foramen Ovale” for the Management of Perioperative Stroke in Patients with Lung Cancer

The Chinese Heart Journal published the “Chinese Expert Guidelines for the Prevention of Stroke Associated with Patent Foramen Ovale” (hereafter referred to as “the Guidelines”) in 2021. The Guidelines were initiated by Professor Yushun Zhang of the No.1 Affiliated Hospital of Xi’an Jiaotong University, and 55 domestic experts participated in their discussion and formulation. The Guidelines focus on eight key issues in the prevention of stroke associated with patent foramen ovale (PFO), including definition and epidemiology, anatomical features, ultrasound diagnosis, clinical screening, and prevention and treatment of PFO-associated stroke. The prevention and treatment of PFO-associated stroke include pharmacological prevention, prevention of PFO with transcatheter occlusion and transcatheter occlusion of PFO. Patients with PFO are at elevated risk of perioperative stroke. In China, lung cancer ranks first in incidence among malignant tumors. The number of lung cancer surgeries is increasing each year, and the incidence of PFO in the population is approximately 25%. Although perioperative stroke in patients with lung cancer due to the presence of PFO has rarely been reported, given the high disability rate of stroke, incidence of PFO, and incidence of lung cancer, herein, we consider the Guidelines for the management of perioperative stroke in lung cancer. Our aim is to provide further perspectives in decreasing the risk of perioperative stroke in patients with lung cancer and PFO, to improve their quality of life and increase the safety of surgery.

Editors' note: Atrial cardiopathy in patients with embolic strokes of unknown source and other stroke etiologies

In the article “Atrial cardiopathy in patients with embolic strokes of unknown source and other stroke etiologies,” Jalini et al. reported atrial cardiopathy in 26.6% of patients meeting the criteria for embolic stroke of unknown source (ESUS) vs 12.1% of patients with large artery atherosclerosis and 16.9% of those with small vessel disease in a cross-sectional study of 846 consecutive patients with ischemic stroke. They also found that patients with ESUS were younger, less hypertensive, and had higher cholesterol and low-density protein levels but fewer left ventricular or atrial abnormalities compared with yet another group with cardioembolism. In response, Drs. Lattanzi and Silvestrini note that they recently found an inverse association between abnormally increased P-wave terminal force in lead V1 (a marker of atrial cardiopathy) and paradoxical or artery-to-artery embolic sources in patients with ESUS. Patients with anterior circulation ESUS more often had ipsilateral (vs contralateral) internal carotid artery plaques with more concerning atherosclerotic findings, whereas younger patients with ESUS had higher incidence of patent foramen ovale (PFO) and lower rates of other vascular risk factors or markers of cardiopathy or atherosclerosis. Stating that ESUS is thus a heterogeneous entity, they encourage the identification of such distinct phenotypes to help guide secondary prevention and potentially targeted interventions. In their reply, the authors agree that the ESUS definition seems too broad and that factors such as PFO, aortic arch, and nonstenotic carotid plaques that were not addressed in their study are important embolic sources in subgroups of patients with ESUS. They note that ongoing trials in subgroups of patients with ESUS will further inform secondary prevention in this population. In the article “Atrial cardiopathy in patients with embolic strokes of unknown source and other stroke etiologies,” Jalini et al. reported atrial cardiopathy in 26.6% of patients meeting the criteria for embolic stroke of unknown source (ESUS) vs 12.1% of patients with large artery atherosclerosis and 16.9% of those with small vessel disease in a cross-sectional study of 846 consecutive patients with ischemic stroke. They also found that patients with ESUS were younger, less hypertensive, and had higher cholesterol and low-density protein levels but fewer left ventricular or atrial abnormalities compared with yet another group with cardioembolism. In response, Drs. Lattanzi and Silvestrini note that they recently found an inverse association between abnormally increased P-wave terminal force in lead V1 (a marker of atrial cardiopathy) and paradoxical or artery-to-artery embolic sources in patients with ESUS. Patients with anterior circulation ESUS more often had ipsilateral (vs contralateral) internal carotid artery plaques with more concerning atherosclerotic findings, whereas younger patients with ESUS had higher incidence of patent foramen ovale (PFO) and lower rates of other vascular risk factors or markers of cardiopathy or atherosclerosis. Stating that ESUS is thus a heterogeneous entity, they encourage the identification of such distinct phenotypes to help guide secondary prevention and potentially targeted interventions. In their reply, the authors agree that the ESUS definition seems too broad and that factors such as PFO, aortic arch, and nonstenotic carotid plaques that were not addressed in their study are important embolic sources in subgroups of patients with ESUS. They note that ongoing trials in subgroups of patients with ESUS will further inform secondary prevention in this population.

Use of Magnetic Resonance Venography in Screening Patients With Cryptogenic Stroke for May-Thurner Syndrome

The purpose of this study was to determine the prevalence of May-Thurner syndrome (MTS) in patients with cryptogenic stroke and to determine the incidence of patent foramen ovale. Magnetic resonance venography of 214 patients with cryptogenic stroke and 50 control patients with abdominopelvic computed tomography scans were evaluated for MTS. Incidence of patent foramen ovale and MTS in the stroke group were significantly greater than the control group (P = 0.0001, P = 0.0023, respectively). In addition, there was significantly greater compression of the left common iliac vein in the stroke group (32%) compared with the control group (13%) (P < 0.00001). In conclusion, there is a significantly higher prevalence of MTS and left common iliac vein compression in patients with cryptogenic stroke. These results indicate that magnetic resonance venography of the pelvis may be appropriate in the evaluation of stroke.

Incidences of aortic and mitral valve strands in patients with migraine with aura.

To analyze the potential association between valvular strands and migraine with aura. During a 1-year period,transesophageal echocardiography was performed in 51 consecutive patients with migraine with aura and 75 control subjects who underwent transesophageal echocardiography for other purposes and had no history of migraine. The presence of aortic and mitral valve strands was evaluated. The incidence of valvular strands was 21.5% (11/51) in migraine patients and 28.0% (21/75) in control subjects (Χ²=0.663, P=0.416). The incidence of patent foramen ovale was significantly higher in patients with migraine with aura than in control subjects (50.9% vs.29.3%) (Χ²=6.302, P=0.012). The incidence of aortic valve strands was significantly higher than that of mitral valve strands in migraine patients (Χ²=4.320,P=0.038). Valvular strands are not associated with migraine with aura and show little clinical significance.

'There are no facts, only interpretations'

This editorial refers to ‘Long-term results of a randomized trial comparing three different devices for percutaneous closure of a patent foramen ovale’, by M. Hornung et al. doi:10.1093/eurheartj/eht283 and ‘Patent foramen ovale transcatheter closure vs. medical therapy on recurrent vascular events: a systematic review and meta-analysis of randomized controlled trials’, by P. Rengifo-Moreno et al. doi:10.1093/eurheartj/eht285 Friedrich Nietzsche's quote in the title could be modified to read ‘There are no facts, only believers’. This modification captures and encompasses many of the issues highlighted in the articles by Hornung et al .1 and Pabb et al .2 related to the complex multifaceted field of patent foramen ovale (PFO) closure and stroke. There are several accepted observations which could serve as facts: 1. PFOs are essential in utero and remain frequent during early and adult life, and are documented in ∼20–30% of asymptomatic individuals. The incidence of PFO is significantly increased in patients with cryptogenic stroke.3 2. Stroke is one of the medical disorders most feared by all patients and ourselves alike. 3. Among the list of multiple conditions, many of which may occur either individually or together in an individual patient and may be either associated with stroke or can result in a stroke, is the presence of a PFO, particularly a complex PFO. 4. The causal relationship between PFO and stroke has been controversial.4 5. A variety of percutaneous devices are available which can close or modify PFOs and abolish right-to-left shunt. 6. There are a number of meta-analyses of observational studies of PFO closure and outcome.5,6 The recent articles by Hornung et al. 1 and Pabb et al. 2 shed some light on …

Incidence of patent foramen ovale and migraine headache in adults with congenital heart disease with no known cardiac shunts

The purpose of this study was to understand why patients with adult congenital heart disease (CHD) but no obvious shunt have an increased frequency of migraine headaches (MH). CHD patients with no known cardiac shunts (CHD-NKS), based on their echocardiographic or angiographic procedures, were tested for a right-to-left shunt using agitated saline contrast transcranial Doppler (TCD). Medical records of 2,920 patients from the UCLA Adult CHD Center were screened to participate in a study to evaluate the prevalence of MH in adults with CHD; 182 patients (6.23%) had CHD-NKS; of these, 60 (30%) underwent a TCD; 23 (38%) tested positive and 37 (62%) tested negative for a right-to-left shunt (P = 0.01 compared with controls). The frequency of MH was 43% in CHD-NKS compared with 11% in controls (P < 0.0001). TCD demonstrated right-to-left shunting in approximately 2/3 of patients with pulmonary stenosis, the Marfan syndrome and congenitally corrected transposition of great vessels, 1/4 of patients with bicuspid aortic valve, 1/5 of patients with mitral valve prolapse and all patients with Ebstein's anomaly. Approximately half of these experienced MH. Patients who had MH did not show a higher frequency of right-to-left shunt when compared with patients without MH (P = 0.57). In conclusion, CHD patients with conditions usually not associated with a shunt have a higher than expected prevalence of PFO which permits intermittent right-to-left shunting undetected by standard non-contrast TTE and TEE; the increased prevalence of right-to-left shunting may partially explain the higher than expected frequency of migraines.

Significant Neurological Presentations in Commando Trained Personnel: Case Studies and Consideration of Differential Diagnosis

A 27-year-old Royal Marine presented to his sickbay following two episodes of sudden onset visual disturbance. A subsequent MRI Scan demonstrated ischaemic changes in the territory of his right posterior cerebral artery. Transthoracic echocardiography was normal but a bubble contrast study was strongly positive indicating the presence of a relatively large patent foramen ovale (PFO). He underwent endovascular closure of his patent foramen ovale and was subsequently upgraded back to full duties. A 35-year-old Army Sergeant presented with sudden onset collapse, right sided weakness, dysarthria and confusion. He was airlifted to a Host Nation hospital and following a normal CT head underwent thrombolysis in the Emergency Department. This was unsuccessful but a CT guided embolectomy led to complete resolution of symptoms. Subsequent transthoracic echo revealed a PFO. He underwent endovascular closure and has since been returned to full duties. The incidence of PFO is common affecting 27% of the population but the incidence of ischaemic stroke in young adults (aged 15-45 years old) is rare. This maybe linked to the size of the PFOs in symptomatic individuals. These case reports emphasise the requirement for further investigation of individuals presenting with collapse and persisting neurology. Differential diagnosis and initial management for primary care and pre-hospital clinicians is also reviewed.

Prevalence of Patent Foramen Ovale and Usefulness of Percutaneous Closure Device in Carcinoid Heart Disease

The aim of this study was to assess (1) the incidence of patent foramen ovale (PFO) in carcinoid syndrome (CS) and (2) the feasibility of percutaneous closure procedure in selected patients with CS. One hundred eight patients were prospectively studied: 54 with CS and an age- and gender-matched control group. All patients underwent conventional and contrast echocardiography. Patients with clinical signs of dyspnea (New York Heart Association class > or =III), cyanosis, carcinoid heart disease (CHD), and severe PFO were referred for the percutaneous closure of PFO. The prevalence of PFO was 41% in patients with CS and 22% in the control group (p = 0.03) and was significantly higher in patients with CHD (59%, p = 0.009). Four patients (14% of those with CHD) were referred for the percutaneous closure of PFO, and 3 patients ultimately underwent PFO closure (using Amplatzer septal occluders). At 6-month follow-up, New York Heart Association class was improved in all patients, as well as arterial blood gas results (p = 0.04) and 6-minute walking distance (p = 0.03), but all patients presented residual right-to-left shunts. In conclusion, this prospective study demonstrates that in patients with CHD, the prevalence of PFO is high and that percutaneous closure of PFO is feasible, with a reduction in symptoms but with residual shunting.

Patent foramen ovale: paradoxical connection to migraine and stroke

In this article we aim to elucidate the relationship between patent foramen ovale, cryptogenic stroke and migraine. Small observational and case-control studies indicate that patients with cryptogenic stroke have a higher incidence of patent foramen ovale. Prospective trials could not show a higher stroke recurrence risk with isolated patent foramen ovale. The combination of patent foramen ovale and atrial septal aneurysm might carry a higher recurrence risk. Secondary prevention with acetylsalicylic acid is as effective as oral anticoagulation, but carries a lower bleeding risk. Whether patent foramen ovale closure prevents recurrent strokes is under investigation. Case-control studies and retrospective analyses indicate comorbidity between patent foramen ovale and migraine, in particular migraine with aura. Recent retrospective studies indicate a reduction in migraine frequency after patent foramen ovale closure (intended for stroke prevention). These studies, however, have major methodological limitations. Therefore patent foramen ovale closure cannot be recommended for the prevention of migraine with aura. At present routine percutaneous closure of isolated patent foramen ovale cannot be recommended for patients with cryptogenic stroke. Patent foramen ovale closure should not be used for the prevention of migraine.

Patent foramen ovale and hypercoagulability as combined risk factors for stroke

The presence of a patent foramen ovale (PFO) is associated with a high incidence of cryptogenic stroke. Hypercoagulable states contribute to venous thromboembolism. The combination of both conditions may greatly increase the risk of stroke, and may indicate the need for long term anticoagulation. This study aimed to determine the incidence of both risk factors (PFO and hypercoagulable state) in a cohort of patients admitted with the diagnosis of stroke. We performed a retrospective chart review of 2028 consecutive patients admitted to the Massachusetts General Hospital through the emergency room who received an initial triage diagnosis of cerebrovascular event between October 1, 1994 and March 17, 1999. Of the 645 patients who had an echocardiogram searching for atrial shunting, 172 (26.7%) had a documented PFO. Of 472 patients who had a hypercoagulability study, an abnormality was identified in 112 (23.7%). Of the 280 patients who had both procedures, 14 (5.0%) were found to have both a PFO and a hypercoagulation abnormality; this represents 17.3% (14/81) of the patients with PFO who underwent a hypercoagulability study. In comparison, 22.1% (44/199) of patients without PFO had a hypercoagulation abnormality. In our series, the incidence of PFO was comparable to that of other reported series. A hypercoagulation abnormality was detected in one fourth of patients who underwent a diagnostic study. The frequency of hypercoagulation abnormality was not higher among patients with a PFO compared to patients without one.

The incidence of patent foramen ovale in 1,000 consecutive patients: A contrast transesophageal echocardiography study: D.C. Fisher, E.A. Fisher, J.H. Budd, S.E. Rosen, M.E. Goldman. Mt. Sinai Medical Center, New York, NY. Chest 1995;107:1504–9

The incidence of patent foramen ovale in 1,000 consecutive patients: A contrast transesophageal echocardiography study: D.C. Fisher, E.A. Fisher, J.H. Budd, S.E. Rosen, M.E. Goldman. Mt. Sinai Medical Center, New York, NY. Chest 1995;107:1504–9

Identification of patent foramen ovale permitting paradoxic embolism

We sought to analyze the morphologic and functional characteristics of the patent foramen ovale in patients with different clinical likelihoods for paradoxic embolism. The incidence of patent foramen ovale is increased in patients with otherwise unexplained arterial ischemic events. Because signs of venous thrombosis are absent in most patients, the diagnosis of paradoxic embolism is often questioned, even when patent foramen ovale is the only potential explanation for the ischemic event. Seventy-eight patients with a patent foramen ovale detected by contrast transesophageal echocardiography were studied: 21 patients with an otherwise unexplained arterial ischemic event and clinical evidence implying paradoxic embolism (group I), 30 patients with an unexplained ischemic event but no clinical evidence for paradoxic embolism (group II) and 27 patients without an ischemic event (group III). During transesophageal contrast echocardiography, patients in group I had more severe right to left shunting (mean +/- SD 52 +/- 16% of the left atrial area filled with contrast medium) and a wider opening of the patent foramen ovale (7.1 +/- 3.6-mm separation between the septum primum and the septum secundum) than did patients in group II (35 +/- 15% and 4.4 +/- 3.2 mm, respectively, p < 0.001) or group III (23 +/- 12% and 3.0 +/- 2.0 mm, respectively, p < 0.001). The incidence of atrial septal aneurysm was similar in the three groups. Severe contrast shunting (> or = 50% of the left atrial area filled with contrast medium) and wide opening of the patent foramen ovale (> or = 5-mm separation) revealed a high sensitivity (71% and 86%, respectively) and high specificity (86% and 96%, respectively) for identification of group I patients. Right to left contrast shunting is more severe and opening of the patent foramen ovale is larger in patients with ischemic arterial events considered to be due to paradoxic embolism. In patients with a patent foramen ovale as the only potential cause for ischemic events and no signs of venous thrombosis, morphologic and functional variables assessed by transesophageal echocardiography may be helpful in estimating the likelihood of paradoxic embolism.

The Incidence of Patent Foramen Ovale in 1,000 Consecutive Patients: A Contrast Transesophageal Echocardiography Study

Patent foramen ovale (PFO) is present in 10 to 35% of people and has been reported to be an important risk factor for cardioembolic cerebrovascular accidents (CVAs) and transient ischemic attacks (TIAs), especially in younger patients. While contrast transthoracic echocardiography has been used to detect PFO, contrast transesophageal echocardiography (TEE) has a greater sensitivity. Prior studies reported the incidence of PFO in patients presenting with a CVA or TIA. To determine the incidence of PFO in a more general population, we reviewed 1,000 consecutive TEEs performed with contrast and color Doppler for the presence of PFO and other cardioembolic risk factors, including atrial septal aneurysm (ASA), aortic plaque, atrial fibrillation (AFib), and atrial thrombi. While imaging with monoplane or biplane TEE, multiple injections of agitated saline solution were injected during cough or Valsalva maneuver to detect flow through a PFO. There were 482 male and 518 female patients with mean age of 60 +/- 17 years (range 11 to 93 years). Patent foramen ovale was found in 9.2% of all patients and, though seen in all age groups divided by decade, the incidence in patients aged 40 to 49 years was greater than those aged 70 to 79 years (12.96% vs 6.15%, p = 0.03). Contrast TEE had a much higher detection rate than color Doppler alone. Importantly, there was no greater incidence of PFO in patients with CVA vs those without CVA, or in male vs female patients. Also, there was a very strong correlation between the presence of ASA and PFO (p < .001). Thus, PFO detected by TEE, frequently seen with ASA, is seen in all age groups and does not in itself present a risk factor for CVA. The association of PFO with peripheral thrombosis and CVA needs further study.

Patent Foramen Ovale: A Potential Source of Cerebral Embolism?

Since the introduction of contrast transesophageal echocardiography (cTEE) and contrast transcranial Doppler sonography (cTCD) the incidence of patent foramen ovale (PFO) has increased, especially in

Venous and paradoxical air embolism in the sitting position. A prospective study with transoesophageal echocardiography.

This prospective study investigates the frequency of patent foramen ovale (PFO), venous air embolism (VAE) and paradoxical air embolism (PAE) by transoesophageal echocardiography (TOE) in neurosurgical patients operated on in the sitting position. The risk of PAE after exclusion of PFO is assessed. A PFO was identified by pre-operative TOE and VAE and PAE by continuous intraoperative TOE. Sixty-two patients were divided into two groups, 22 patients were studied in group 1 (posterior fossa surgery) and group 2 (cervical surgery) contained 40 patients. Pre-operative TOE demonstrated a PFO in 5 of the 22 patients in group 1 (23%). Patients with proven PFO were excluded from the sitting position. Two further patients of this group (12% of 17 patients), in whom a PFO had been excluded pre-operatively, nevertheless had PAE, air occurring in all cavities of the heart. In group 2 the incidence of PFO was 4 out of 40 patients (10%). No PAE was observed in this group. Three morphological types of VAE with different haemodynamic and ventilation changes were demonstrated. VAE was observed in 76% of all posterior fossa operations and in 25% of cervical laminectomies. We conclude that a pre-operative search for PFO is mandatory considering its incidence of 23% in group 1 and of 10% in group 2, and the risk of PAE. If a PFO is detected, the sitting position should be avoided. A residual risk for PAE remains despite exclusion of PFO because the reliability of TOE is limited. TOE is the method of choice for detecting VAE and PAE.

Accuracy of color Doppler transesophageal echocardiography for diagnosis of patent foramen ovale.

This study assessed the sensitivity of color Doppler as compared with contrast study during transesophageal echocardiography for detection of a patent foramen ovale. We also evaluated the incidence of patent foramen ovale in younger (less than age 50, group 1) as compared with older (greater than age 50, group 2) patients. A total of 114 patients were studied. A patent foramen ovale was found in 17 patients: 7 of 39 (17.9%) in group 1 and 10 of 75 (13.3%) in group 2 (NS). The sensitivity of color Doppler as compared with contrast study was 33%. Our data suggest that color Doppler is a poor method of assessment for the presence of a patent foramen ovale and that patent foramen ovale remains prevalent in older as well as younger patients.

Plantar power: reproducibility of the plantar response.

BMJ 1992;304:482 shunt) in this group. This compares favourably with a postmortem study of normal hearts that showed the incidence of patent foramen ovale to be about 27%.s We conclude that the presence of a right to left shunt in a diver without a history of decompression sickness may be irrelevant. On current information, there is probably not a case for the routine screening of divers (or, indirectly, potential divers) for shunts.