The Annals of Thoracic Surgery, Vol 54, 44-49, Copyright © 1992 by The Society of Thoracic Surgeons
Usefulness of right ventricular indices in early diagnosis of cardiac tamponade
JW Jones, NN Izzat, MN Rashad, JI Thornby, TR McLean, LG Svensson and AC Beall Jr
Cora and Webb Mading Department of Surgery, Baylor College of Medicine, Houston, Texas.
Early diagnosis of postoperative cardiac tamponade is impeded by its
clinical similarity to left ventricular failure. Moreover, the hemodynamic
changes necessary to diagnose cardiac tamponade are detected by
conventional monitoring technique only after clinical compromise. Early
signs of cardiac tamponade and left ventricular failure were studied with
emphasis on right ventricular function in anesthetized dogs. One group (n =
20) had cardiac tamponade produced by incrementally increasing pericardial
pressure (2 to 20 mm Hg), and another group (n = 20) had acute left
ventricular failure produced by successive ligation of the anterior
descending coronary artery at the lower, middle, and upper thirds. Besides
standard hemodynamic measurements, right ventricular function was examined
with a rapid- response thermodilution catheter. During cardiac tamponade,
cardiac output, right ventricular ejection fraction, right ventricular
stroke volume, and right ventricular end-diastolic volume were
significantly decreased from baseline values after a pericardial pressure
of 8 mm Hg or more (p less than 0.05). Right atrial and pulmonary arterial
pressures were not significantly elevated until 14 and 20 mm Hg of
pericardial pressure, respectively. Although cardiac function in the left
ventricular failure group was reduced after each ligation, right
ventricular ejection fraction remained unchanged. This study suggests that
right ventricular indices may facilitate earlier diagnosis of cardiac
tamponade with greater accuracy.
