Prerequisites to salvage profound biventricular failure patients with ventricular assist devices.
We conducted chronic experiments to determine how to treat profound biventricular failure systematically with ventricular assist devices (VADs) and to analyze the factors that affect prognoses for this condition. Anoxic arrest was induced in ten goats by aortic cross-clamping under normothermic conditions (38.5 degrees C) for 30 (n = 3), 45 (n = 1), and 60 (n = 6) minutes. A left ventricular assist device (LVAD) was implanted in eight animals, and a biventricular assist device (BVAD) was used in two. Three goats--two of which had undergone anoxic arrest for 30 minutes and one for 60 minutes--whose right atrial pressure (RAP) was approximately 18 mm Hg during the acute stage, recovered in two to three weeks, and the pumps were successfully removed. Pathological findings in these animals showed scattered areas of surviving myocardium, with connective tissue replacing the degenerated myocardium. The remaining five LVAD goats required higher RAPs to maintain circulation and died from various causes. Maintaining circulation without volume loading, even in the presence of arrhythmias, was easier with the BVAD. One BVAD animal that underwent 45 minutes of anoxic arrest recovered from right ventricular failure, and the right pump was removed. The second goat (anoxic arrest, 60 min) on the BVAD failed to recover. Autopsy of the myocardium revealed a thin ventricular wall. Our studies show that the use of VADs allows time for a failing heart to recover, but the potential for healing is affected by the severity of myocardial damage prior to VAD application.(ABSTRACT TRUNCATED AT 250 WORDS)
Nakatani
T
T
Department of Artificial Organs, National Cardiovascular Center, Osaka, Japan.
Takano
H
H
Noda
H
H
Taenaka
Y
Y
Umezu
M
M
Kinoshita
M
M
Fukuda
S
S
Matsuda
T
T
Iwata
H
H
Takatani
S
S
D000818:Animals; D001243:Assisted Circulation; D004562:Electrocardiography; D006041:Goats; D006324:Heart Arrest, Induced; D006333:Heart Failure / Q000473:pathology*; D006353:Heart-Assist Devices; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000473:pathology; D009206:Myocardium / Q000473:pathology; D009336:Necrosis; D015427:Reperfusion Injury / Q000473:pathology*