A 68-year-old woman presented to our hospital complaining of dyspnea at rest for approximately 2 months and was classified as New York Heart Association functional class III. She had previously been treated for breast and colon cancers and had not suffered from cardiovascular disease. Her height, weight, and body mass index were 150.0 cm, 91.0 kg, and 40.4 kg/m2, respectively. A grade IV/VI pan-systolic murmur was heard at the apex on cardiac auscultation. Her pulse rate was 105 beats/min and she was diagnosed with an irregularly rapid heartbeat (tachycardia). Her blood pressure was 124/76 mmHg. A chest radiograph revealed severe cardiomegaly with a cardiothoracic ratio of 80%, while an electrocardiogram showed persistent atrial fibrillation with a low-voltage F-wave. Computed tomography demonstrated the retention of pleural fluid or abdominal dropsy and hepatosplenomegaly. No significant coronary stenosis was observed by coronary angiography. Transthoracic echocardiography revealed severe mitral regurgitation with annular enlargement and severe tricuspid regurgitation. The cause of mitral regurgitation was severe tethering due to extreme annular enlargement, and the prolapse of the anterior leaflet. The left ventricular ejection fraction was 49%, the left ventricular diastolic diameter was 63 mm, and the left atrial diameter was 71 mm. Laboratory evaluations did not show any abnormalities, apart from an N-terminal-proB-type natriuretic peptide level of 7439 pg/ml. Because of the medication-refractory heart failure, we decided to perform surgery after a written informed consent was obtained.\nA median sternotomy was performed and standard cardio-pulmonary bypass was initiated with ascending aortic and bicaval cannulation. A left atrial vent was introduced from the right upper pulmonary vein. Myocardial protection was achieved in an antegrade and retrograde fashion. The retrograde cardioplegia cannula was inserted smoothly under direct vision. After aortic cross-clamping, the left atrium was opened through a longitudinal left atriotomy, revealing the tethering mechanism secondary to the prolapse of the anterior leaflet of the mitral valve. The clear zone of the anterior leaflet was excised and the rough zone with its attached chord were divided equally. Each divided structure was transferred to the anterolateral and the posteromedial commissures separately. The posterior leaflet, including the subvalvular apparatus, was wholly preserved. The mitral valve was replaced with a 29-mm St. Jude mechanical valve (St. Jude Medical Inc., St. Paul, MN) in an intra-annular position using everting mattress sutures. Subsequently, tricuspid annuloplasty was performed with a 32-mm Carpentier-Edwards PhysioTricuspid ring (Edwards LifeSciences, Irvine, CA) for annular enlargement. Weaning from the cardio-pulmonary bypass was successful. After closing the thorax, to our surprise, an atrial mass of 3 cm × 2 cm was detected by TEE, which showed an oval hypoechoic appearance extending from the posterior annulus of the mitral valve to the posterior wall of the left atrium (Fig. a). Although it occupied one-third of the left atrium, there was no significant obstruction of the pulmonary venous return and left ventricular filling. The prosthetic valve movement was unobstructed and there were no paravalvular leaks or pericardial effusion. No communication between the mass and the atrial true lumen was detected using color Doppler echocardiogram. We diagnosed the mass as LAD. Because hemodynamic conditions were stable after a consulting with the anesthesiologist, the patient was deemed unsuitable for surgery. She was transferred to the intensive care unit and remained under close observation. On postoperative day 2, TEE showed that the atrial mass had vanished and the broken piece of the endocardium merely remained fluttering in the atrium (Fig. b). On postoperative day 6, the appearance of the left atrium had normalized completely, leaving no traces of LAD (Fig. c). The patient had an uneventful postoperative course, except for prolonged respiratory failure. She was discharged from the hospital on postoperative day 47 and is currently being followed up once a month.
A 51-year-old female presented with a LA mass suggesting myxoma detected by transthoracic echocardiography (TTE) incidentally during a routine check-up. Her past medical history was unremarkable. Her vital sign was stable and blood examinations showed no abnormalities. Her initial electrocardiogram showed normal sinus rhythm without any significant ST-T change, and chest X-ray revealed nothing abnormal. On preoperative TEE, there was a cystic mass (1.7 × 1.3 cm-sized) that was attached to the atrial septum in the LA, without any evidence of valvular insufficiency or stenosis. Similar findings were observed in thoraco-abdominal computed tomography angiography.\nMinimal invasive surgery was planned on patient request and thus incision through right 4th anterior thoracotomy under total cardiopulmonary bypass (CPB) was performed, and myocardial protection was achieved using anterograde cardioplegia. About 1.5 cm-sized yellowish gray mass with cystic cavity was successfully removed from the LA septum, and then inter-atrial septum and right atrium were directly closed without using any prosthetic materials. Weaning of CPB went smoothly, and the postoperative clinical conditions were stable and uneventful without hemodynamic compromise. Pathological review confirmed that the mass removed was cardiac myxoma.\nOn postoperative day 4, TTE was performed to look into her overall postoperative condition, and unexpectedly a new large mass occupying the entire LA was found (). It minimally increased transmitral pressure gradient. Follow-up thoraco-abdominal CT angiographic findings were in line with that found on TTE (). Since newly detected LA mass on CT had 60 Hounsfield units, it was hard to identify what the mass was. It only gave us little information on the real nature of the mass, thrombus versus recent bleeding. For the diagnostic confirmation, thus, CMR was undergone, and showed a 5.4 × 4.4 × 4.0 cm-sized ovoid mass adjacent to the posterior and inferior wall of LA with obtuse angle. It was covered by fibrous smooth wall, meaning intramural rather than intra-atrial condition. Gadolinium enhancement was not observed on early post-contrast T1-weighted images. The mass showed low signal intensity on long-time interval delayed enhancement sequence, and displayed intermediate signal intensity on T1-weighted images and a high signal intensity on T2-weighted images, highly suggestive of acute hematoma, rather than recent bleeding (). Since her vital sign was stable and she was totally asymptomatic, conservative management and close medical follow-up were recommended without additional invasive procedures, and then after a few days of monitoring, she was uneventfully discharged on the post-operative day 8. She has been doing well after discharge, and any other complication was not observed on regular exam. The size of LA intramural hematoma was getting smaller and transmitral pressure gradient decreased on TTE which was performed on the postoperative day 50 (). CMR performed 5 months after index operation demonstrated that LA intramural hematoma finally disappeared ().