Rubine Gevorgyan

Sensitivity of Transcranial Doppler Versus Intracardiac Echocardiography in the Detection of Right-to-Left Shunt

OBJECTIVES The purpose of this study was to understand the reason for variation in the sensitivity of different methods of detecting right-to-left shunts (RLS). BACKGROUND Patent foramen ovale (PFO) is implicated in the pathogenesis of cryptogenic stroke, decompression illness, and migraine headaches. Intravenous agitated saline injections with tomographic imaging (transthoracic, transesophageal, and intracardiac echocardiography) has been used for detecting intracardiac shunts. Some patients with a high clinical suspicion of PFO have inconclusive echocardiographic study results. Transcranial Doppler (TCD) is an alternative method for detecting RLS that is not dependent on tomographic imaging. METHODS Thirty-eight consecutive patients who were undergoing PFO closure had simultaneous transcranial Doppler and intracardiac echocardiography performed. Agitated saline injections were performed at rest, with Valsalva maneuver, and with forced expiration into a manometer to 40 mm Hg before and after closure, as well as 3 or more months after closure. Right atrial pressures were measured in the periprocedural period, and RLS were graded according to standard methods during these maneuvers. RESULTS Right atrial pressures were significantly higher with Valsalva maneuver compared with rest (before closure 21.6 +/- 11.9 mm Hg vs. 6.6 +/- 2.6 mm Hg, p < 0.001; after closure 28.4 +/- 13.9 mm Hg vs. 6.8 +/- 2.6 mm Hg, p < 0.001) and with manometer compared with Valsalva maneuver (before closure 38.7 +/- 6.6 mm Hg vs. 21.6 +/- 11.9 mm Hg, p < 0.001; after closure 44.0 +/- 9.5 mm Hg vs. 28.4 +/- 13.9 mm Hg, p < 0.001). Intracardiac echocardiography underestimated shunting in 34% of patients with Valsalva maneuver or manometer after closure compared with TCD. CONCLUSIONS Transcranial Doppler with immediate feedback provided by forced expiration against a manometer to 40 mm Hg is more sensitive than echocardiographic imaging for the detection of RLS. These observations have significant implications for determining the incidence of RLS in patients with stroke or migraine.

The Effect of Patent Foramen Ovale Closure on Visual Aura Without Headache or Typical Aura With Migraine Headache

OBJECTIVES The aim of this study was to assess the prevalence of right-to-left (R to L) shunt in patients with visual aura and evaluate the effect of shunt closure on resolution of aura. BACKGROUND Right-to-left shunting is associated with migraine headache (MH) with aura. Some patients present with visual aura without headaches. It is unclear whether visual aura without headache is a form of migraine or a transient neurologic dysfunction. METHODS Of patients referred to the University of California, Los Angeles for suspected patent foramen ovale (PFO), 225 had visual aura with or without MH. Patients were assessed for a shunt and evaluated for MH and/or visual aura. They were divided into 3 groups: 1) visual aura associated with MH; 2) visual aura unrelated in time to MH; and 3) visual aura without MH. The frequency of R to L shunt was compared with a control group of 200 patients. Eighty patients underwent PFO closure. Residual shunts, MH, and visual aura were reassessed after 3 and 12 months. RESULTS The prevalence of R to L shunt in Groups A, B, and C was 96%, 72%, and 67%, respectively, versus 18% in the control group (p < 0.0001). The frequency of shunting was similar in Group B versus Group C, but much higher in all 3 groups compared with control subjects. Twelve months after PFO closure, symptoms of aura were resolved in 52%, 75%, and 80% of patients in Groups A, B, and C, respectively (p = NS). CONCLUSIONS The similar distribution of R to L shunting in all 3 patient groups and the correlation between PFO closure and improvement of aura suggests a similar pathophysiology between the presence of PFO and the visual aura phenomenon, whether or not headache is present in the symptom complex.

The effect of patent foramen ovale closure in patients with platypnea‐orthodeoxia syndrome

Platypnea‐orthodeoxia syndrome is a rare condition characterized by hypoxemia in the upright position that is improved in the supine position. Although several etiologies of platypnea‐orthodeoxia exist, it is frequently associated with right‐to‐left shunting of blood at the cardiac or pulmonary level, usually via a patent foramen ovale (PFO). The aim of this study was to evaluate the incidence of platypnea‐orthodeoxia syndrome in a select patient population with right‐to‐left shunting and to describe the outcomes after PFO closure.

Patent foramen ovale: Unanswered questions.

The foramen ovale is a remnant of the fetal circulation that remains patent in 20-25% of the adult population. Although long overlooked as a potential pathway that could produce pathologic conditions, the presence of a patent foramen ovale (PFO) has been associated with a higher than expected frequency in a variety of clinical syndromes including cryptogenic stroke, migraines, sleep apnea, platypnea-orthodeoxia, deep sea diving associated decompression illness, and high altitude pulmonary edema. A unifying hypothesis is that a chemical or particulate matter from the venous circulation crosses the PFO conduit between the right and left atria to produce a variety of clinical syndromes. Although observational studies suggest a therapeutic benefit of PFO closure compared to medical therapy alone in patients with cryptogenic stroke, 3 randomized controlled trials (RCTs) did not confirm the superiority of PFO closure for the secondary prevention of stroke. However, meta-analyses of these RCTs demonstrate a significant benefit of PFO closure over medical therapy alone. Similarly, observational studies provide support for PFO closure for symptomatic relief of migraines. But one controversial randomized study failed to replicate the results of the observational studies while another two demonstrated a partial benefit. The goal of this review is to discuss the clinical conditions associated with PFO and provide internists and primary care physicians with current data on PFO trials, and clinical insight to help guide their patients who are found to have a PFO on echocardiographic testing.

Comparison of residual shunt rates in five devices used to treat patent foramen ovale.

To assess the effective closure rate among devices used for transcatheter patent foramen ovale (PFO) closure, and to discuss the management of patients with large residual shunts.

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 Ebsteins 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.

A Comparison of Methods to Detect and Quantitate PFO: TCD, TTE, ICE and TEE

At the present time, the diagnosis of a patent foramen ovale (PFO) is based on either imaging of the interatrial septal anatomy that allows direct visualization of the septal defect transesophageal echo [TEE], transthoracic echo [TTE], intracardiac echo [ICE], or by physiologic quantification of the right-to-left shunt (RLS) through the PFO using transcranial Doppler [TCD]. Contrast TEE is currently the standard technique for identifying a PFO and visualization of the atrial septal anatomy. TEE permits an assessment of PFO size, RLS severity and differentiation between an intracardiac and intrapulmonary RLS. A TTE bubble study is the most commonly used imaging modality for the detection of PFO. Though cost-effective and readily available, TTE has a low sensitivity with poor differentiating ability between cardiac and pulmonary RLS. ICE allows detailed visualization of the inter-atrial septum at a resolution comparable to that of TEE. TCD is a highly sensitive test for indirectly assessing the presence of a RLS; some studies report a sensitivity higher than that of TEE but a lower specificity due to TCD’s inability to differentiate between cardiac and pulmonary shunts. This chapter will compare the different techniques and describe the benefits and drawbacks of the various imaging options.

Sensitivity of brachial versus femoral vein injection of agitated saline to detect right-to-left shunts with Transcranial Doppler

Transcranial Doppler (TCD) can detect a right‐to‐left shunt (RLS) with high sensitivity but has a 5% chance of a false negative study. TCD is usually performed with injection of agitated saline into an arm vein. We compared the sensitivity of TCD performed from the brachial versus femoral veins.

Visual migraine aura with or without headache: association with right to left shunt and assessment following transcutaneous closure

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CARDIAC CATHETERIZATION IN PATIENTS WITH END STAGE LIVER DISEASE: RISKS AND OUTCOMES

Results: Of the 301 records reviewed, 47 patients (15.5%) were diagnosed with CAD on angiography and 33 (70%) of them had PCI. 106 patients (35%) received an OLT. Of 94 (31%) deaths, the majority (82/94) were from liver disease. Peri-catheterization bleeding episodes occurred in only 4 patients (1%); classified as TIMI Minor (1) and TIMI Minimal (3). The sensitivity and specificity of Lexiscan Myoview Stress Test were 50% and 91%, and for Adenosine Stress Test: 61.5% and 93.5%. The prevalence of patients on dialysis-pre-catheterization was significantly higher in those with CAD compared to those ESLD patients without CAD (p=0.04). The death rate in all patient groups was similar; the mean age at the time of death was the highest in patients who underwent PCI prior to OLT.