Postoperative cardiac tamponade due to mediastinal blood clot or fluid under tension may remain latent for some days after open heart surgery. The initial clinical state frequently masquerades as a state of refractory congestive cardiac failure or a mild low cardiac output syndrome producing mental disorientation. When severe tamponade eventuates there is an extreme surgical emergency, but as one to two weeks may have elapsed since surgery the significance is often missed.
The classical picture of tamponade due to pericardial fluid as described by Stewart et al1 may occur, but usually there is mediastinal tamponade similar to the acute traumatic mediastinal hematomata described by Endress2 and Al-Naaman,3 or an encysted collection of clot about the heart producing local compression of one or more cardiac chambers.4
This paper describes seven cases of latent tamponade at Pacific Medical Center which have been instructive in avoiding errors in diagnosis
Hill JD, Johnson DC, Miller GE, Kerth WJ, Gerbode F. Latent Mediastinal Tamponade After Open-Heart Surgery. Arch Surg. 1969;99(6):808-814. doi:10.1001/archsurg.1969.01340180132025