A 61-year-old woman arrived at our emergency department because of the appearance of intense palpitations for 3 days. She denied cardiovascular risk factors or a previous cardiac disease, did not assume pharmacological therapy, and reported only a recent domestic accidental fall without apparent complications. The heart rhythm appeared tachycardic and irregular, and the remaining vital parameters were normal with a good hemodynamic compensation (systemic blood pressure 135/75 mmHg, SaO2 98%). Electrocardiogram reported atrial fibrillation with high ventricular response (136 bpm). The blood tests were all normal, except for a mild and nonspecific increase in the high-sensitivity troponin T.\nThe patient underwent a cardiology consult in order to plan the following therapy procedure. Subsequent transthoracic echocardiogram revealed a dilated LA with an interior septum which extended across the longitudinal length of the atrial chamber, by causing the obstruction to the left ventricular (LV) filling, in the absence of additional pathologic findings. By considering that the atrial fibrillation had begun more than 48 h before and the need of investigating the above findings, we have decided to perform a transesophageal echocardiogram (TEE) the following day.\nThe TEE documented the presence of atrial thrombosis in the appendage, a spherical image with clear margins and fibrin branches inside, and a seamless cleavage with the posterolateral wall of the LA, which determined an obstacle to the ventricular filling [].\nWe decided to perform an urgent contrast-enhanced cardiac computed tomography (CT) which confirmed a capsulated lesion within the posterolateral left atrial wall with sharp margins and a basal density of + 30 HU, without any significant contrast enhancement in the arterial and late phases, features resembling those of a chronic hematoma [].\nAfter a consultation with our cardiac surgeon, and suspecting an atrial dissection, we planned to perform a cardiac magnetic resonance (CMR). CMR was performed with a 1.5T scanner with cine B-TFE, black-blood turbo spin echo, phase-sensitive inversion recovery, and THRIVE sequences before and after a standard 0.2 mmol/kg gadolinium contrast agent dose. CMR confirmed the intramural formation, within the inferolateral wall of the LA, with diameters of 4.3 cm × 6.2 cm × 4.4 cm, characterized by marked hyperintensity in T2-weighted sequences and high signal in both unsuppressed and fat-suppressed T1-weighted images, as well as the absence of signs of local invasiveness; a thin hypointense rim demarcated the lesion in the steady-state cine sequences. In contrast-enhanced images, a thin rim of peripheral enhancement is appreciated, mostly evident on the posterior side. These findings were deemed compatible with the original hypothesis of an intramural hematoma of the wall of the atrium, probably subacute/chronic [].\nIn consideration of the extension of the intramural hematoma and the LV inflow tract obstruction, the patient underwent a surgery to empty the hematoma and reattach the atrial wall.\nHistological examination confirmed the presence of histiocytes, crenated red blood cells, and crystals, hence a chronic hematoma [].
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 ().