The Annals of Thoracic Surgery, Vol 31, 214-223, Copyright © 1981 by The Society of Thoracic Surgeons
Influence of potassium cardioplegia versus ischemic arrest on regional left ventricular diastolic compliance in humans
JD Slack, JV Zeok, JS Cole, HG Hanley, AL Cornish and HE McKean
To compare the effects of hypothermic ischemic arrest versus hypothermic
potassium cardioplegia, regional left ventricular performance was monitored
in 20 adult male patients undergoing saphenous vein bypass operation.
Twelve patients received ischemic arrest (Group 1), and 8 received
potassium cardioplegia (Group 2). Groups 1 and 2 did not differ in left
ventricular ejection fraction (0.62 versus 0.60), number of bypassed
vessels (3.7 versus 3.4), mean cross-clamp time (75 versus 63 minutes), or
mean cardiopulmonary bypass time (182 versus 170 minutes). Before
cardiopulmonary bypass was begun, a pair of ultrasonic crystals was secured
in the left ventricular anterior myocardium to measure segment motion and a
micromanometer- tipped catheter was placed in the left ventricular chamber.
All patients received a saphenous vein bypass graft to a vessel supplying
the anterior left ventricular wall in the region of the ultrasonic
crystals. Comparison of changes in systolic measurements revealed no
significant differences between Groups 1 and 2. After saphenous vein bypass
grafting, the left ventricular end-diastolic pressure (11.4 to 17.0 mm HG)
and modulus of left ventricular segment stiffness (0.37 to 0.67, p less
than 0.02) were elevated in Group 1 but no changes were observed in Group 2
(14.0 to 15.6 mm Hg, and 0.16 to 0.24, respectively). Compared with
hypothermic ischemic arrest, hypothermic potassium cardioplegia is not
associated with an increased left ventricular diastolic stiffness shortly
after saphenous vein bypass grafting in humans.
