Despite recent reports describing survival after
cardiac rupture, the effectiveness of circulatory support while awaiting definitive surgical treatment is controversial. To assess the efficacy of volume expansion and pharmacologic support in
cardiac tamponade due to
cardiac rupture, a model of hemorrhagic
cardiac tamponade was developed and treatment with rapid saline infusion and
dobutamine was compared with rapid saline infusion alone in 15 closed chest dogs. A right ventricular
wound of reproducible size was produced by deflating an aortic valvuloplasty balloon that had previously been passed by way of the internal jugular vein into the pericardial space and through a
stab wound in the right ventricular free wall. Hemodynamic values were compared at baseline, during tamponade and after a rapid infusion (1 liter at 100 ml/min) of either
saline solution alone or
saline solution plus
dobutamine (20 micrograms/kg per min). Atrial and pericardial pressures increased significantly in both groups. Mean arterial pressure, cardiac output and stroke volume increased with combined saline and
dobutamine infusion to values similar to those at baseline (91 +/- 19%, 114 +/- 43% and 94 +/- 37% of baseline, respectively). In contrast, saline infusion alone caused a small increase in cardiac output but failed to significantly increase mean arterial pressure or stroke volume (76.8 +/- 14.2%, 55 +/- 18% and 51 +/- 17% of baseline, respectively). Combined rapid infusion of
saline solution and
dobutamine infusion has a more beneficial hemodynamic effect and may be more effective than rapid saline infusion alone in resuscitating patients with hemorrhagic
cardiac tamponade due to
cardiac rupture.