Fatal pulmonary embolism from large right atrial thrombus.

An 88-year-old woman experienced altered consciousness. Her caregiver noticed that she was unresponsive to calls an hour before the visit. Her symptoms had already disappeared upon arrival at the hospital, but prior to discharge, stroke-like symptoms such as left facial paresis, pronator drift and abnormal speech suddenly occurred. However, her symptoms disappeared within minutes, and the laboratory examinations, computed tomography and magnetic resonance imaging of the brain did not reveal any specific findings. She was dismissed only to return the next day with severely impaired consciousness, agitation, tachypnea (40/min) and livedo on both legs. A large free-floating mass (69 × 11 mm; Fig. 1A and B and video upon request), which looked like a tumor, in the right atrium protruding into the right ventricle on echocardiography and pulmonary hypertension with a mean pulmonary artery pressure of 45 mmHg supported the clinical diagnosis of pulmonary embolism. Treatment was initiated immediately but was unsuccessful, and the patient died 5 h later. An autopsy revealed a right atrial thrombus (Fig. 1C) and large bilateral pulmonary emboli (Fig. 1D). We concluded that this combination led to reduced cardiac output, altered consciousness, stroke-like symptoms and, ultimately, death.

Figure 1

(A and B) Transthoracic echocardiography showing the right atrial thrombus (arrows) extending into the right ventricle: apical five-chamber view. RA, right atrium; RV, right ventricle; LV, left ventricle; AV, aortic valve. (C and D) Autopsy findings of the right atrium and ventricle thrombus and bilateral pulmonary thromboembolism. (C) Thrombus adherent to the wall of the right chamber (arrow); (D) blood clots in both pulmonary arteries (arrows).

Intracardiac thrombi are more common in the left (15–20%) than the right atrium (3–6%), but the latter might be underdiagnosed [1]. These right-heart thrombi are commonly in transit, having migrated from the venous system [2]. Pulmonary embolism is often accompanied by a right heart thrombus, which is associated with an over 40% mortality rate [2, 3]. Echocardiography is the key diagnostic examination [3]. We missed this life-threatening condition in our patient because of the nonspecific symptoms and the rarity of her condition. A high level of awareness of this fatal condition may save future patients with similar conditions.

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