Prediction of functional recovery of 60-minute warm ischemic hearts from asphyxiated canine non-heart-beating donors.
BACKGROUND
Cardiac function of non-heart-beating donors (NHBDs) is uncertain due to severe myocardial damage. We developed an isolated myocardial perfusion system to resuscitate NHBD hearts and attempted to predict functional recovery of 60-minute warm ischemic hearts by analyzing systolic and diastolic functions.


METHODS
Hypoxic cardiac arrest was induced in 8 mongrel dogs without any pre-treatments. After 60-minute ischemia, intracoronary microthrombi were flushed out by retrograde blood cardiopledia with tissue-type plasminogen activator. Coronary arteries were initially perfused from the aortic root with tepid hyperkalemic blood (20 mmol/liter) at low pressure (20 mm Hg) for the first 60 minutes and then with normothermic blood for the next 60 minutes. After 120 minutes of reperfusion, pre-load was increased for ejection against an after-load of 80 mm Hg. Pressure-volume loops were recorded to obtain the end-systolic pressure-volume relationship (ESPVR) and end-diastolic pressure-volume relationship (EDPVR). Stroke volume at a given pre-load was calculated from averaged ESPVR, EDPVR and after-load identical to an averaged baseline value. The Frank-Starling relationship was obtained and cardiac status was classified according to Forrester's hemodynamic sub-set.


RESULTS
End-systolic elastance decreased significantly to about 60% of baseline and the time constant of isovolumic relaxation was prolonged significantly by about 20%. Cardiac index was decreased to about 50% and cardiac status was classified in the Forrester III or IV sub-set.


CONCLUSIONS
The extent of functional recovery of NHBD hearts is predictable by cardiac output. Although 120 minutes of recovery time may be short for 60-minute ischemic damage, this system may be feasible to predict post-transplant cardiac function before transplantation.
Hirota
Masanori
M
Department of Cardiovascular Surgery, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan. mhirota@md.okayama-u.ac.jp
Ishino
Kozo
K
Fukumasu
Ichiro
I
Yoshida
Kazuhiro
K
Mohri
Satoshi
S
Shimizu
Juichiro
J
Kajiya
Fumihiko
F
Sano
Shunji
S
D000818:Animals; D001794:Blood Pressure; D004285:Dogs; D006323:Heart Arrest / Q000139:chemically induced; D006324:Heart Arrest, Induced / Q000379:methods; D016027:Heart Transplantation; D017202:Myocardial Ischemia / Q000503:physiopathology*; D015425:Myocardial Reperfusion / Q000379:methods*; D009926:Organ Preservation / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology