The Annals of Thoracic Surgery, Vol 22, 546-556, Copyright © 1976 by The Society of Thoracic Surgeons
A servocontrolled atrial-aortic assist device: experimental findings and clinical experience
H Laks, JD Marco, TL Farmer, JW Standeven, GC Kaiser and VL Willman
A servocontrol system was developed to regulate a single roller pump left
atrial-aortic (La-A) assist device. Responsiveness of the servomechanism to
blood volume changes, myocardial damage, and mitral regurgitation was
evaluated in 5 sheep and 6 dogs. Myocardial damage was induced by occlusion
of coronary arteries. and the hemodynamic effects of La-A assistance were
evaluated. While La-A assistance reduced left atrial pressures to low
levels, the left ventricular end- diastolic pressure remained elevated in
the severely damaged heart. LaA- assistance was used in 3 patients. Two
were weaned from cardiopulmonary bypass after failure of intraaortic
balloon counterpulsation, and 1 is a long-term survivor. The third was
supported for 48 hours after attempt repair of complex congenital heart
disease. The servocontrol device added to the safety of prolonged La-A
assistance. This mode of assistance should be considered when intraaortic
balloon counterpulsation has failed.
