[Cardiac assist device with skeletal muscle ventricle--alternate-drive twin pump system as a countermeasure to prevent skeletal muscle fatigue].
Many studies on cardiac assist devices using skeletal muscle ventricle (SMV) require preconditioning for 6-9 weeks as a countermeasure to prevent skeletal muscle fatigue. Therefore this method does not seem to be indicated in cases of acute heart failure. However we performed experiments to develop Alternate-Drive Twin SMVs as a cardiac assist device without preconditioning. Adult mongrel dogs were used. In order to obtain adequate alternating SMV during pattern, fundamental experiments were performed. The function of SMVs prepared by rolled pedunculated sartial muscle was studied hydrodynamically in three groups; continuous driving for one hour in group a (n = 3): intermittent driving for 3 hours in group b (n = 15): intermittent driving for 12 hours in group c (n = 3). Group b was divided into three subgroups with interval for 10 minutes in subgroup I (n = 5), for 20 minutes in subgroup II (n = 5), for 30 minutes in subgroup III (n = 5). In group b and c, the recess interval between driving was set the same as the driving interval in each subgroup. All SMVs were stimulated by electrical bursts. In every experiment pump pressure, pump max dp/dt and pump stroke work index/10 kg body weight were measured for 3 hours. In subgroups I and II, pump function decreased gradually, however, the parameters did not show any change for up to 3 hours in subgroup III. We defined the reduction ratio as the difference of parameters before and after driving divided by the value at the start of driving.(ABSTRACT TRUNCATED AT 250 WORDS)
Suesada
H
H
Department of Surgery, Tokyo Medical College, Japan.
Hirayama
T
T
Fujikawa
T
T
Osada
K
K
Shimizu
H
H
Ishimaru
S
S
Furukawa
K
K
D000818:Animals; D004285:Dogs; D004867:Equipment Design; D005221:Fatigue / Q000517:prevention & control*; D006353:Heart-Assist Devices; D009132:Muscles; D009135:Muscular Diseases / Q000517:prevention & control*