This study was designed to compare the effects of juxtaaortic balloon counterpulsation (JABC), performed in ascending aorta and the aortic arch, with those yielded by intraaortic balloon counterpulsation (IABC) in descending aorta, in experimental animals during induced cardiac failure. JABC was achieved with a manufactured Dacron prosthesis and a balloon pump placed between the prosthesis and the wrapped aorta. JABC resulted in a significant increase of cardiac output (from 2.33+/-0.82 to 2.61+/-1.12 L/min, p < 0.05), cardiac index (from 0.071+/-0.025 to 0.080+/-0.033 L/min/kg, p < 0.05) and diastolic pressure augmentation evaluated through diastolic and systolic areas beneath the aortic pressure curve (DABAC/SABAC) index (from 0.94+/-0.21 to 1.10+/-0.33, p < 0.01). End diastolic aortic pressure showed a significant decrease with JABC (from 31.90+/-7.09 to 27.83+/-9.72 mm Hg, p < 0.05). A close association between percentage of DABAC/SABAC increases obtained with IABC and JABC was observed (r2 = 0.67; p < 0.001). Counterpulsation obtained by a juxtaaortic catheter placed in the arch and the ascending wrapped aorta results in an effective hemodynamic improvement comparable with that achieved by an intraaortic catheter in open chest sheep.