The Annals of Thoracic Surgery, Vol 34, 58-65, Copyright © 1982 by The Society of Thoracic Surgeons
Functional and metabolic preservation of the immature myocardium with verapamil following global ischemia
VA Starnes, JW Hammon Jr, FM Lupinetti, RD Olson, RJ Boucek Jr and HW Bender Jr
This study investigated the effects of the calcium antagonist verapamil on
the functional and biochemical recovery of the immature heart following 30
minutes of normothermic ischemia. Verapamil (0.2 mg per kilogram of body
weight) was infused into the aortic root in 5 puppies (8 to 10 weeks of
age) prior to cardiopulmonary bypass. Five additional puppies received
saline solution as a control. Left ventricular developed pressure, rate of
rise of left ventricular pressure (dP/dt), left ventricular endsystolic
pressure-diameter relationship (emax), compliance, and water content were
assessed before and after bypass. Serial myocardial biopsies for adenosine
triphosphate (ATP) and creatine phosphate were obtained. Puppies pretreated
with verapamil recovered more than 80% of the preischemic left ventricular
developed pressure, dP/dt, and emax in contrast to 50% recovery in the
controls (p less than 0.05). The ATP content declined 40% during the
interval of ischemia in the control puppies, versus 14.6% in the
verapamil-treated puppies (p less than 0.05). Myocardial compliance was
preserved in the verapamil-treated puppies and was associated with
significantly less myocardial water content (78% versus 80.1% in the
controls)(p less than 0.01). This study demonstrates the protective effects
of verapamil on the immature heart during ischemic arrest. These results
suggest that verapamil may be a useful adjunct to current methods of
protecting the infant heart during cardiopulmonary bypass.
