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 55-year-old man presented with rheumatic heart disease, severe mitral regurgitation, moderate pulmonary arterial hypertension, and good biventricular function. He was scheduled for mitral valve replacement (MVR). After applying standard monitors and preoxygenation, general anesthesia was induced with 2 mg of midazolam, 50 mg of propofol, 200 μg of fentanyl, 60 mg of lidocaine, and 8 mg of vecuronium. Anesthesia was maintained with oxygen: Air, 1% isoflurane, and intermittent doses of fentanyl. The trachea was intubated with an 8.5-mm single-lumen tracheal tube. A right femoral arterial catheter was placed for continuous blood pressure monitoring.\nMVR with 29 mm St. Jude mechanical prosthetic valve with posterior mitral leaflet preservation was performed through transseptal approach on conventional cardiopulmonary bypass (CPB) and cold blood cardioplegia. The patient was weaned off CPB with the optimal inotropic support of 5 μg/kg/min of dopamine and 5 μg/kg/min dobutamine. But, the pressures were on borderline around 80/38 mmHg, and right ventricle appears to be distending with poor myocardial contractions. So, we decided to put transesophageal echocardiography (TEE) probe to see for any abnormality. To our surprise, we saw a circular hypoechoic mass in the left atrial (LA) free wall encroaching onto the mitral valve []. This finding was discussed with the surgeon, who decided to re-explore the LA. LA atriotomy was reopened, the mitral valve appeared to be well seated, and there was no evidence of dissection. Only the LA free wall appeared to have subendocardial blood collection. There were no continuities between the cavity and the LA, left ventricle, posterior pericardial space. Marsupialization of the cavity is done and opened it to the LA cavity [].\nThe patient was then weaned from CPB for the 2nd time with inotropic support of 0.375 μg/kg/min of milrinone, 5 μg/kg/min of dopamine, 5 μg/kg/min dobutamine, and 0.05 μg/kg/min of nor epinephrine. The post-bypass TEE examination showed that LA dissection (LAd) wall appeared to be incised in the middle and drained out the blood.\nThe patient's postoperative course was complicated by intermittent periods of desaturation which required bi-level airway pressure ventilation with which he showed improvement in oxygenation. The patient was discharged from the hospital 15 days after surgery.