The Journal of Thoracic and Cardiovascular Surgery, Vol 84, 762-772, Copyright © 1982 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
How should clear cardioplegia be administered? A method of rapid arrest with high flow and pressure
JE Molina, KS Gani and DM Voss
Most of the currently described methods of administering cardioplegia
appear to be less than optimal because of low flows utilized and slow
cardiac arrest evolving over a period of several minutes. This may account
for some reports of suboptimal protection, namely ventricular dysfunction
and elevation of cardiac isoenzymes in the blood following operation. A
method of pressurized injection of clear cardioplegic solution with
immediate cardiac arrest (6 to 4.1 seconds) is described. The technique
utilizes a 16 Fr. cannula under a driving pressure of 300 mm Hg, which
gives an aortic root pressure of 80 to 105 mm Hg (mean 98 mm Hg).
Monitoring of serum glutamic oxaloacetic transaminase (SGOT), creatine
kinase (CK) MB, and lactate dehydrogenase (LDH1 and LDH2) isoenzymes was
carried out in 200 consecutive cases of aorta-coronary bypass. Myocardial
infarct index (MII), calculated from the CK disappearance value, measured a
mean of 5.3. Peak value of CK-MB occurred immediately after operation (2
hours) and ranged from 10.2 +/- 2.6 IU for 30 minutes of ischemia to 13.3
+/- 4.2 IU for 61 minutes, gradually decreasing to less than 2 IU in 48
hours. None of the patients required inotropic agents postoperatively and
89.9% had spontaneous re-establishment of normal cardiac beat following
coronary reperfusion. The electrocardiogram (ECG) failed to show any
detectable myocardial infarction during this period of time. The system
satisfactorily protected the heart for up to 70 minutes of ischemia. The
total amount of cardioplegic solution used for 60 minutes measured 1,200
+/- 200 ml. Myocardial temperature dropped to 15 degrees C within 12 +/-
4.3 seconds. The method more closely approximates the ideal flows and
pressures for the coronary vascular bed and size of the adult human heart.
