Ex vivo heart preparation
A total of 4 mongrel dogs (25-40 kg in weight) were placed under deep
sedation with isoflurane inhalational anesthesia. A left lateral
thoracotomy allowed visualization of the heart and great vessels.
Therapeutic heparinization was confirmed (activated clotting time
> 300 s) after which the aorta was cannulated to allow
cardioplegia solution to be administered in a retrograde fashion. After
asystole was achieved, cardiectomy was performed and the heart was
immediately cooled to 4°C. A large animal Langendorff perfusion
apparatus (Radnoti, Covina, CA, USA) was used to perfuse the heartex vivo in a warmed basin (Figure
1 )(14). The hearts were perfused with a
modified Krebs‐Henseleit solution which was oxygenated with 95% O2 and
buffered to 5% CO2(15). The perfusate
solution consisted of the following: NaCl (118 mmol/L),
NaHCO3 (25 mmol/L), mannitol (16 mmol/L), d-glucose (11
mmol/L), KCl (4.7 mmol/L), sodium pyruvate (2.3 mmol/L),
CaCl2 (2.0 mmol/L),
KH2PO4 (1.18 mmol/L),
MgSO4 (1.17 mmol/L), and human insulin (10 U/L; Novolin;
Novo Nordisk, Plainsboro, NJ). The perfusate temperature was maintained
at 37°C±1°C.