Impending Paradoxical Cerebral Embolism in a Patient With Atrial Septal Aneurysm

Abstract

atent foramen ovale (PFO) and atrial septal aneurysm (ASA) have been identified as potential risk factors for stroke; 1-5 when transesophageal echocardiography (TEE) is used, the prevalence of PFO in the normal population is as high as 22-38%. 6 However, it is often difficult to prove that the mechanism of systemic embolism was paradoxical embolism in stroke patients with PFO. 1 We present a case of impending paradoxical cerebral embolism diagnosed by TEE and contrast echocardiography. Case ReportAn 89-year-old man was admitted to the Hokushin General Hospital with hemiparesis of the left limbs and impaired consciousness. On physical examination, he had normal heart sounds, left hemiparesis, and no swelling of the lower limbs. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain showed cerebral infarction in the area of the right middle cerebral artery (Fig 1). Magnetic resonance angiography (MRA) showed no atherosclerotic changes in the large cerebro-vascular walls. Electrocardiogram showed sinus rhythm and he had an episode of chronic atrial fibrillation before admission. The chest X-ray and laboratory data presented no abnormalities.Because there was no definite evidence of artery to artery stroke, we performed transthoracic echocardiography (TTE) to rule out a cardiac source of the emboli. TTE showed a slightly enlarged right ventricle, mild tricuspid regurgitation (max pressure gradient =34 mmHg), atrial septal aneurysm, and a floating mass in the left atrium (Fig 2A). To further examine that mass, we performed TEE, which showed a large string-like mass transiting from the right atrium (RA) to the left atrium (LA) through the atrial septum (Fig 2B), and the absence of any thrombus on the left atrial appendage (Fig 2C).We diagnosed paradoxical cerebral embolism caused by intra-atrial thrombus. Peripheral Doppler echocardiography of the lower extremities revealed normal flow velocities and no existence of deep vein thrombosis. A hypercoagulability profile for intravascular blood stasis was also negative.We chose anticoagulation therapy rather than surgical embolectomy because of the patient's age and poor general condition. After 4 weeks of warfarin therapy, the atrial mass had completely disappeared from the TEE images. Right-to-left shunt flow was not identified with color flow Doppler, although it was proved with a contrast study under the provocative maneuver (Fig 3). We used a microbubble contrast agent (Levovist R , Shering Co Ltd) instead of hand-agitated saline to avoid possible systemic air Circ J 2005; 69: 246 -248 (Received September 10, 2003; revised manuscript received January 19, 2004; accepted February 18, 2004) Departments of Cardiology and *Neurology, Hokushin General Hospital, Nagano, Japan Mailing address: Toshihiko Takamoto, MD, FACC, Department of Cardiology, Hokushin General Hospital, 1-5-63 Nishi, Nakano, Nagano 383-8505, Japan. E-mail: ttakamoto-circ@umin.ac.jp Impending Paradoxical Cerebral Embolism in a PatientWith Atrial Septal Aneurysm

Thromboembolus Crossing Patent Foramen Ovale: Appearance in Multislice Computed Tomography and Echocardiography

“…Transesophageal echocardiography is an efficient tool to investigate a transseptal thrombus and provides together with real-time three-dimensional reconstruction an outstanding method in this situation. [1][2][3][4] Disclosure Statement None.…”

“…The foramen ovale remains patent in about 22%-38% 1) of individuals after the establishment of adult circulation and has been identified as a risk factor for the development of stroke.…”

Does the Morphology of Atrial Septal Aneurysm Influence Cerebral Arterial Embolus Occurrence?

“…4,5 Paradoxical embolism is still considered as the mechanism of embolic events in patients with ASA. [13][14][15][16][17] We focused mainly on the strict, but possible to confirm, diagnosis of endpoints such as ischemic stroke and arterial systemic embolus but TIAs were also evaluated in 20.5%. We found arterial emboli in 13.6% of patients with ASA (almost all had ischemic stroke except for one person) and taking into account the size of our study group the result seems to be similar to that of other investigators.…”

“…Therefore, ASA was found in about 60% of all diagnosed cases, especially in young patients 4,5 . Paradoxical embolism is still considered as the mechanism of embolic events in patients with ASA 13–17 . We focused mainly on the strict, but possible to confirm, diagnosis of endpoints such as ischemic stroke and arterial systemic embolus but TIAs were also evaluated in 20.5%.…”

Postpartum paradoxical cerebral embolism through an unknown patent foramen ovale

“…acute pulmonary embolism or valsalva maneuver during straining at defecation or cough, which causes a reversal of shunt from right to left atrium through a preexisting PFO or a small atrial septal defect (ASD). Potential mechanisms of stroke in patients with atrial septal defects include embolus from a venous source, direct embolisation from thrombi formed within an atrial septal aneurysm and the formation of thrombus as a result of atrial arrhythmias [7,8].…”