Development of a direct mechanical left ventricular assist device for left ventricular failure.
We have developed a direct mechanical left ventricular assist device (DMLVAD) for severe left ventricular failure. The DMLVAD was attached to the left ventricle and compressed the heart by a pneumatic driving unit. In a mock circulation model with an extracted nonbeating heart, a cardiac output (CO) of 1.93 L/min was obtained at a driving pressure of 200 mm Hg. In a canine left ventricular failure model induced by injection of sodium hydroxide into the myocardium, the systolic arterial pressure, systolic left ventricular pressure, maximum LV dP/dt, peak flow, and CO increased by 21, 24, 58, 144, and 37%, respectively. The mean left atrial pressure also decreased by 15% when the DMLVAD was driven. These effects were most prominent when the mean left atrial pressure was over 15 mm Hg, and the driving pressure was over 100 mm Hg. Compression at late systole was more effective in obtaining greater CO. We suggest that the DMLVAD could be an optional circulatory assist device for patients with left ventricular failure awaiting heart transplantation.
Hotei
H
H
First Department of Surgery, Hiroshima University School of Medicine, Japan.
Koura
Y
Y
Orihashi
K
K
Sueda
T
T
Fukunaga
S
S
Matsuura
Y
Y
D000818:Animals; D001794:Blood Pressure; D002302:Cardiac Output; D002424:Caustics; D004195:Disease Models, Animal; D004285:Dogs; D004562:Electrocardiography; D006321:Heart / Q000503:physiopathology; D006353:Heart-Assist Devices; D012972:Sodium Hydroxide; D018487:Ventricular Dysfunction, Left / Q000139:chemically induced / Q000503:physiopathology / Q000628:therapy*
D002424:Caustics; D012972:Sodium Hydroxide