Frequency and Clinical Significance of Atrial Cavities in situ Thrombosis: A Large-Scale Study and Literature Review.

BACKGROUND

Atrial tachyarrhythmias are the main cause of atrial thrombosis, and are usually in the left appendage. The prevalence and causes of endocavitarian thrombosis have not been investigated in recent large-scale studies. Aim of our work was to describe the epidemiology, the clinical characteristics and predisposing factors of "extra-appendicular" atrial thrombosis and to report a systematic review of recent literature.

METHODS AND

RESULTS

5,862 consecutive adult patients referred to a transesophageal echocardiographic exam, were enrolled. A total of 175 subjects with Atrial Thrombosis were found with a prevalence of 2.98%; among those 22 was found in left (0.38%) and 2 in the right (0.03%) atrium. Among the 22 patients with left atrial thrombosis, 8 were associated with prosthetic valves, 4 with mitral stenosis and the remaining with hypercoagulative conditions (cancer, septic shock, eosinophilic pneumonia, cardiogenic shock and warfarin under-dosage in permanent atrial fibrillation and decompensated heart failure). Cancer was associated in one of the two patients with a right atrial clot. The review of the literature from 2000 to December 2019 revealed conflicting results of 48 case reports of atrial cavity thrombosis; pooling this data proved the rarity of extra-appendage thrombosis and confirmed its association with a valvular heart disease or a systemic hypercoagulable state.

CONCLUSIONS

Atrial "extra-appendage" thrombosis is a rare condition usually associated to "valvular" atrial fibrillation (such as prosthetic valves and mitral stenosis). A minority, but significant, cases are secondary to a thrombophilic conditions. In absence of valvular heart disease an underlying condition should be sought.