A valveless counterpulsation left ventricular assist pump in the descending aorta: hemodynamic benefit with a reduced risk of XXXX .

@entity64 @entity235 @entity999 @entity33863 @entity340
Because of @entity340 and @entity999 reported with use of the total artificial heart, the descending aorta was reexamined as a site for a valveless counterpulsation left ventricular assist pump. The pump was introduced into the thoracic aorta at the level of the eight thoracic vertebra in 11 @entity235 right-heart bypass preparations. Heart rate (110 beats per minute), @entity64 volume (20 ml), and mean arterial pressure (80 or 100 mm Hg) were precisely controlled. The pump ejection volume was adjusted to equal 1 time or 2 times the @entity64 volume of the @entity235 . A 20-ml ejection led to an 11% reduction in left atrial pressure, an 11% reduction in peak left ventricular pressure, and a 20% reduction in tension time index (all, p less than .05 at a mean arterial pressure of 80 mm Hg). Systolic shortening (ultrasonic crystals) increased by 5% (p less than .05 at a mean arterial pressure of 80 mm Hg). A 40-ml pump ejection led to an 11% reduction in mean left atrial pressure, a 17% reduction in peak left ventricular pressure, and a 21% reduction in tension time index (all, p less than .05 at a mean arterial pressure of 80 mm Hg). The systolic shortening increased by 15% (p less than .05). To assess the relative risk of @entity999 , albumin spheres (40 to 60 micrograms) labeled with @entity33863 were injected into the pump chamber in 5 @entity235 (40-ml ejection, 2.1 +/- 0.1 times the @entity235 's @entity64 volume).(ABSTRACT TRUNCATED AT 250 WORDS)
