**2. Case report 1**

A 59-year-old Asian female referred to our surgical team was admitted to our hospital for investigation of ASA after complaining of frequent palpitations starting eight years previously. ASA had been confirmed two years earlier in an examination for palpitation, to which the patient was very sensitive, making frequent visits to the emergency department. The arrhythmia consisted of paroxysmal atrial fibrillation (AF), which was refractory to antiarrhythmic medication. The medication did not include any anticoagulant or antiplatelet agents. Physical examination was normal. Auscultation detected no murmurs, rubs, or gallops, but a split S1 was noted. Laboratory data on admission were within normal limits except for slightly elevated liver enzyme, possibly due to chronic hepatitis C. Initial EKG showed no abnormality. Chest radiograph demonstrated a cardiothoracic ratio of 0.50 and no remarkable findings. TTE revealed a giant ASA with mobility into the right atrium and nearly prolapsing into the tricuspid orifice (Figure 1). It also showed a mildly dilated right

© 2012 Hosoba et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2012 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

ventricle with no valvular dysfunction. Right ventricular systolic pressure was calculated to be 43 mm Hg. Chest computed tomography (CT) with contrast dye showed 47×22 mm of protruding tissue at the site of the atrial septum. Transesophageal echocardiogram demonstrated PFO at a site close to the superior vena cava and ascending aorta. In view of the enlarged right ventricle and paroxysmal AF, in addition to the high risk of stroke, surgical repair was recommended and performed.

The surgical approach was through medial sternotomy. Cardiopulmonary bypass was established and bilateral pulmonary vein isolation was performed with a bipolar radiofrequency device. Right atriotomy was then carried out. The aneurysm lay next to the fossa ovalis, enabling detection of PFO (Figure 2). The aneurysm in the interatrial septum was removed, a right atrium maze procedure was performed, and the defect was closed with a 4-0 polypropylene running suture.

The patient tolerated surgery very well and had an uneventful postoperative recovery without occasional paroxysmal AF. A postoperative MRI was performed, but no shunt flow was detected. TTE showed the same result. The patient was discharged uneventfully after surgery and remains symptom-free and in good health at two years postoperatively.

Macroscopically, the mass consisted of a thin protrusion of the atrial septum. The histological results from the septum showed a degenerative cardiac muscle with fibrosis. There was no evidence of atherosclerosis, specific inflammation, or tumorous lesion.

**Figure 1.** Giant atrial septal aneurysm (47×23 mm) with mobility into the right atrium nearly prolapsing into the tricuspid orifice

**Figure 2.** Intraoperative picture showing 50×25 mm of protruding tissue at the site of the atrial septum

### **3. Case report 2**

472 Aneurysm

ventricle with no valvular dysfunction. Right ventricular systolic pressure was calculated to be 43 mm Hg. Chest computed tomography (CT) with contrast dye showed 47×22 mm of protruding tissue at the site of the atrial septum. Transesophageal echocardiogram demonstrated PFO at a site close to the superior vena cava and ascending aorta. In view of the enlarged right ventricle and paroxysmal AF, in addition to the high risk of stroke,

The surgical approach was through medial sternotomy. Cardiopulmonary bypass was established and bilateral pulmonary vein isolation was performed with a bipolar radiofrequency device. Right atriotomy was then carried out. The aneurysm lay next to the fossa ovalis, enabling detection of PFO (Figure 2). The aneurysm in the interatrial septum was removed, a right atrium maze procedure was performed, and the defect was closed

The patient tolerated surgery very well and had an uneventful postoperative recovery without occasional paroxysmal AF. A postoperative MRI was performed, but no shunt flow was detected. TTE showed the same result. The patient was discharged uneventfully after

Macroscopically, the mass consisted of a thin protrusion of the atrial septum. The histological results from the septum showed a degenerative cardiac muscle with fibrosis.

**Figure 1.** Giant atrial septal aneurysm (47×23 mm) with mobility into the right atrium nearly prolapsing

surgery and remains symptom-free and in good health at two years postoperatively.

There was no evidence of atherosclerosis, specific inflammation, or tumorous lesion.

surgical repair was recommended and performed.

with a 4-0 polypropylene running suture.

into the tricuspid orifice

A 37-year-old Asian woman with a 10-month history of general malaise and dyspnea was referred to our division. The patient had been well until a month earlier, when she began to have episodes of chest oppression. Transthoracic echocardiography showed almost normal wall motion without valvular dysfunction apart from the unusual feature of atrial septal defect (ASD) (Figure 3). It showed the atrial septum extending into right atrium and multidirectional right to left shunt flow using the color Doppler image. The ejection fraction was 64% and the shunt ratio was 50% (Qp/Qs=2.0). The patient was referred to our surgical team as a case of ASD.

The patient underwent an ASD closure. Following medial sternotomy, cardiopulmonary bypass was established. Right atriotomy was then carried out. The defect appeared to resemble ASD secundum, but protruded as seen in ASA had two large cribriform holes and numerous small pinholes (Figure 4). The aneurysm in the interatrial septum was removed and the defect was closed with a 4-0 polypropylene running suture.

The patient tolerated surgery very well and had an uneventful postoperative recovery without symptoms. The patient was discharged uneventfully after surgery and remains symptom-free and in good health at 12 months postoperatively.

**Figure 3.** Echocardiography showing shunt flow through atrial septal defect. The multiple direction of the flow suggested the presence of a number of holes in the atrial septum.

**Figure 4.** Figure 4. Atrial septum with numerous small pinholes and cribriform atrial septal defect
