Intraoperative detection of patent foramen ovale by transesophageal echocardiography

This study reports the intraoperative use of contrast and Doppler echocardiography techniques to diagnose patent foramen ovale (PFO). Fifty patients without known atrial septal defects undergoing elective cardiovascular surgery were studied. A 5-MHz esophageal echocardiographic probe was used to image the fossa ovalis (FO) and 10 ml agitated saline was injected into the right atrium during apnea. Echocardiographic contrast was then injected during end-inspiration at 20-cmH2O airway pressure. When opacification of the right atrium was complete, the airway pressure was released. During these maneuvers, color and pulsed-wave Doppler interrogation of the atrial septum were also performed. Right-to-left passage of saline contrast across the interatrial septum was seen in 11 of 50 patients (22%). Doppler echocardiography demonstrated a PFO in 2 patients without contrast evidence of shunting. Thus, the combination of contrast and Doppler echocardiography identified a 26% (13 of 50) prevalence of PFO, approximating the previously reported autopsy rate of 25%. These contrast and Doppler techniques may be useful in detecting patients at risk for paradoxical emboli and in identifying candidates for closure of the PFO.     

Timing of transesophageal echocardiography in diagnosing patent foramen ovale in patients supported with left ventricular assist device

Left ventricular assist devices unload the left ventricle and decrease left atrial pressure. This hemodynamic change may cause a right to left atrial shunt and hypoxemia in patients with patent foramen ovale. We prospectively studied the best time for performing diagnostic transesophageal echocardiography in left ventricular assist device patients. Intraoperative transesophageal echocardiography was performed in 14 patients before cardiopulmonary bypass was initiated and after left ventricular assist device was implanted. No patent foramen ovale was detected when transesophageal echocardiography was done before bypass, but a patent foramen ovale was found in 3 patients when transesophageal echocardiography was performed after left ventricular assist device was activated. Patent foramen ovale was confirmed by inspection in all three patients and surgically closed during the same procedure. There were no patent foramen ovale closure-related complications.     

Improved technique to diagnose a patent foramen ovale during left ventricular assist device insertion

Diagnosis of a patent foramen ovale prior to left ventricular assist device placement can be quite difficult, and if missed may result in a significant hypoxemia due to a right to left shunt. We describe a simple and precise way to increase the diagnostic accuracy of patent foramen ovale detection prior to initiating cardiopulmonary bypass for left ventricular assist device placement.     

Paradoxical embolus caught in transit through a patent foramen ovale

Diagnosing a paradoxical embolism is challenging, and it can be proven only if the thrombus is identified across the intracardiac defect. Very few cases have been diagnosed as an impending paradoxical embolism. Recently, the diagnosis and management of these entities have greatly improved with the advent of transesophageal echocardiography (compared with transthoracic echocardiography). Pulmonary hypertension may cause right-to-left shunting across a patent foramen ovale and predispose development of a paradoxical embolism. We report a patient with an impending paradoxical embolism that was caught in transit across the patent foramen ovale. The patient was treated successfully with emergent surgery.     

Transcatheter closure of patent foramen ovale for hypoxemia during left ventricular assist device support

The diagnosis of a patent foramen ovale (PFO) is a dynamic process and it is based on the detection of blood shunting at the atrial level. Only under abnormal physiologic conditions, such as with a left ventricular assist device (LVAD), when right atrial pressure (RAP) exceeds left atrial pressure (LAP) the PFO may cause hypoxemia due to a right-to-left shunt. We report the closure of a PFO using a transcatheter approach in a patient on LVAD support.     

Transcatheter closure of patent foramen ovale for hypoxemia during left ventricular assist device support.

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.     

Contrast echocardiography and transcranial Doppler sonography for detection of a patent foramen ovale

We report the case of a patient, in whom a patent foramen ovale was detected. For the detection of a patent foramen ovale simulation of Valsalva's manoeuvre with a positive airway pressure of 20 cm H2O was applied. Change of ventilation manoeuvre by ventilation with positive airway pressure of 35/30/15 cm H2O at a tidal volume of 1200 ml make a distinct increase in passage of contrast medium from the right to the left atrium. These findings were detected by contrast transesophageal echocardiography and indirectly by transcranial Doppler sonography and were reproducible. This may stress the importance of preoperative screening of patent foramen ovale in patients to be operated on in the sitting position. Contrast echocardiography and the ventilatory manoeuvre with high airway pressure and PEEP might increase the detection rate of patent foramen ovale with a right to left shunt during general anaesthesia.     

Diagnosis and management of entrapped embolus through a patent foramen ovale

The diagnosis of impending paradoxical embolus by echocardiography is exceptional and its management remains unclear. Through a personal case, we performed an exhaustive review of the medical literature of this rare finding. Since the first report, only 43 cases have ever been reported. The superiority of transesophageal echocardiography is underlined. The clinical features are complex. The classical simultaneous pulmonary and paradoxical embolism is often absent. Therapeutic options are cardiac surgery, thrombolysis or anticoagulation. The early mortality rate is high (21%). In addition, recurrent embolisms are reported when a medical treatment is chosen. The cumulative results of each possibility are described.     

Septic paradoxical embolus through a patent foramen ovale after pacemaker implantation

A case of a septic paradoxic embolus due to an infected pacemaker lead associated with a patent foramen ovale (PFO) is described. Treatment consisted of immediate intracardiac embolectomy, pericardial patch closure of the PFO, total removal of the infected pacemaker lead and generator, and placement of a new permanent epicardial lead pacemaker system.     

Removal of a left atrial thrombus adherent to a patent foramen ovale occluder

A 62-year-old man presented with bilateral thromboembolic occlusion of the lower leg arteries 8 months after closure of a patent foramen ovale with an Amplatzer patent-foramen-ovale occluder (AGA Medical Corporation, Plymouth, MN). Then he developed an acute myocardial ischemia. A left heart catheter revealed thromboembolic occlusion of the right coronary artery, and echocardiography demonstrated a thrombus attached to the device within the left atrium. Cerebral computer tomography showed a new ischemic lesion. In an emergency procedure, the device and the left atrial thrombus were removed, the septal defect was closed, and a coronary artery bypass grafting was performed. The patient was discharged from the hospital in stable condition.     

经胸超声心动图声学造影评价隐源性脑卒中与卵圆孔未闭的关系

目的应用经胸超声心动图声学造影(cTTE)技术探讨隐源性脑卒中(CS)与卵圆孔未闭(PFO)的关系。方法收集190例CS患者(CS组)及190例年龄、性别相匹配的非卒中对照组患者,并根据年龄分为中青年亚组(≤55岁)及老年亚组(55岁)。应用cTTE技术检查CS组及对照组PFO发生率,对PFO的发生率及缺血性脑卒中危险因素进行组间对照分析,Logistic回归分析PFO与CS的关系。结果中青年CS亚组及老年CS亚组的PFO检出率及PFO合并房间隔瘤(ASA)检出率均高于同年龄段对照组(P0.05)。二元Logistic回归分析PFO是CS的独立危险因素。PFO检出率在中青年CS亚组与老年CS亚组间差异无统计学意义(P0.05)。cTTE检查可显著提高PFO检出率。cTTE检查中CS组右向左分流分级为2、3级的例数较同年龄段对照组明显增多(P0.05)。结论 PFO在不同年龄人群CS的发病中起着重要作用,PFO合并ASA及cTTE检出右向左中到大量的分流能增加脑卒中的风险。经胸超声心动图结合cTTE可作为PFO的常规检查方法。