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Singh et al. Myocardial protection in cardiac transplantation

depolarization. Intracellular calcium sequestration for cardiac preservation [Table 1] [23] .
occurs via active transport across an ATP-dependent
pump allowing relaxation of the myocardium in diastole. Histidine-tryptophan-ketoglutarate (custodiol/
Repolarization however is prevented by the high bretschneider)
potassium concentration of the cardioplegic solution. Reichenspurner et al. [24] studied the effect of histidine-
Both intracellular and extracellular cardioplegic tryptophan-ketoglutarate (HTK) in a cohort of 600
solutions have similar long-term outcomes [14] . (524 male:76 female) patients undergoing heart
transplantation over a 10-year period (1981-1991).
Norman Shumway first noted the use of topical They reported good results provided the ischaemic
hypothermia to reduce myocardial metabolic times were less than 4 h.
requirements in 1960 when chemical cardioplegia
fell out of favour [15] . Denton Cooley then attempted Sung et al. [25] compared Bretscheinder’s HTK solution
intermittent aortic occlusion and utilized Kay’s work (18 patients) and cold blood cardioplegia (CBC) (49
with intracoronary blood perfusion with cross clamp patients) for myocardial protection in donor heart
fibrillation [16-18] . preservation. Cold HTK solution was infused at low
perfusion pressure after procurement and the donor
Clinical cardioplegia was reintroduced in the 1970s by heart was placed in a sterile bag containing HTK
using a low-sodium solution by Bretschneider et al. [19] solution. The CBC group heart was placed in St
with potassium chloride [20] that was reported as safe Thomas’ Hospital (StH). The heart was covered with
and allowed safer aortic cross-clamping allowing cold ice-cold saline for topical cooling and packed in a
crystalloid cardioplegic solutions to be in favour for container filled with ice. Two patients (11.1%) in the
general cardiac surgery. Blood was later introduced HTK group died within 30 days of surgery due to right
as medium for cardioplegia by Buckberg as it was heart failure and pneumonia with septic shock. There
later discovered that reperfusion injuries occurred were 4 deaths (8.2%) in the CBC group due to acute
in crystalloid cardioplegia due to the associated rejection (n = 2), right heart failure and pneumonia
influence of calcium and oxygen as described with septic shock. There was no statistically significant
by Buckberg [21] and Hearse et al. [22] . There are difference between thebypass time, ischaemic time
intracellular and extracellular types of crystalloid short term outcomes, creatine kinase/CKMB/troponin
cardioplegia which have become the gold standard I values, length of ICU stay, and hospital stay between

Table 1: Comparison of cardioplegic solutions contents
University of St Thomas’s
HTK [15] Celsior [14] Eurocollins [17]
Wisconsin [16] Solution [18]
Intracellular/extracellular Extracellular Intracellular Extracellular Intracellular Extracellular
Na + 10 25 100 10 120
K + 10 120 15 115 16
Ca 2+ 0.015 0 0.25 0 1.2
Mg 2+ 4 5 13 0 16
Cl – 50 20 0 15 160
Glucose – 0 0 180 0
Others a-KG Adenosine 0 0
Glucose 0 0 0 195 0
Impermeant/colloid
Hydroxyl-Ethyl Starch (g/L) 0 0 50 0 0
Lactobionate 0 0 100 80 0
Mannitol 30 0 60 0
Raffinose 0 0 30 0 0
Buffer
Phosphate 0 25 0 100 0
Bicarbonate 0 0 0 10 10
Histidine 180 0 30 00
Osmolarity (mOsm/L) 310 330 320 375 320
Anti-oxidants
Glutothione 0 2 3 0 0
Allopurinol 0 1 0 0 0
Tryptophan 2 0 0 0 0
All units expressed in mmol/L unless otherwise indicated
Vessel Plus ¦ Volume 1 ¦ December 28, 2017 215