The Journal of Thoracic and Cardiovascular Surgery, Vol 74, 907-912, Copyright © 1977 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The effects of thoracotomy on coronary blood flow in the dog
JC Yeager and FJ Haddy
A velocity-sensitive catheter-tip flowmeter was used to measure left
coronary arterial blood flow prior to, during, and following left lateral
thoracotomy in the artificially ventilated dog anesthetized with sodium
pentobarbital. Thoracotomy was performed with (six dogs) and without (10
dogs) the addition of an increased expiratory airway resistance. Opening
the chest without the increased airway resistance had no effect on coronary
blood flow, despite a fall in arterial pressure, because coronary vascular
resistance decreased. This was associated with a fall in arterial PO2.
Thoracotomy with the airway resistance in place caused a transient slight
fall in coronary flow owing to decreased arterial pressure and increased
coronary resistance. All changes disappeared by the twelfth minute.
Arterial PO2 was unaffected. Under the conditions of this experiment,
thoracotomy had surprisingly little effect on coronary blood flow.